WO2025196670A1

WO2025196670A1 - System and method for power saving generator control

Info

Publication number: WO2025196670A1
Application number: PCT/IB2025/052893
Authority: WO
Inventors: Howard Rosen
Original assignee: Individual
Current assignee: Individual
Priority date: 2024-03-20
Filing date: 2025-03-19
Publication date: 2025-09-25
Anticipated expiration: 2026-09-20

Abstract

A system to control generator that provides power to a facility. The facility has a plurality of powered devices including a critical device that operates to maintain an operating parameter within a predefined range. The system enters an extreme reserve mode (ERM) of operation the remaining capacity of the generator is below an ERM threshold. During ERM, the generator is turned off when the operating parameter value of the meets a first ERM condition and turned on when the operating parameter value meets a second ERM condition. The ERM threshold can be dynamically determined and can be adjusted in response to changing conditions. Prior to entering ERM, the system enters reduced power modes as one intermediate thresholds are reached and selectively disconnects other devices from power.

Description

SYSTEM AND METHOD FOR POWER SAVING GENERATOR CONTROL

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional patent application Serial No. 63/567,640, filed March 20, 2024 and to U.S. Provisional patent application Serial No. 63/725,323, filed November 26, 2024. The entire contents of each are expressly incorporated by reference.

BACKGROUND:

Electrical power is essential for daily living. Most homes, business, and other facilities are connected to supply lines that carry electricity generated by remote power stations. While electrical supply grids are generally reliable, they are subject to disruption, which can result in a power outage. To prepare for this, a building can be coupled to a local emergency generator. Various automatic switching systems are known that operate to detect when main power goes out and, in response, start the generator. The generator is allowed to run until the system detects that main power is restored.

Fig 1 is a high level diagram of a conventional stand-by generator system 100 which is commonly used to provide temporary power during a utility power outage. Main power from the local utility meter 105 is fed through an automatic transfer switch 110 to the main service panel 115 for the facility. The service panel distributes the power to the various electrical loads 120 at the facility, such as HVAC systems, lighting, septic pumps, electric door controls, fire and security devices, etc., as well as the various outlets through which a multitude of other devices can be powered.

Generator 125 is one that can be automatically started and stopped in response to a power outage. The generator is powered by fuel, such as gasoline, diesel, natural gas, or propane, stored in a tank 130. In the event that local utility power fails, the power outage is detected by the transfer switch 110 which signals the generator 125 to turn on and transfers input for power to the service panel 115 from the main power 105 to power supplied by the generator 125. Alternatively, a generator control circuit 135 separate from the transfer switch 110 can monitor the status of main power and, when a power failure is detected, operate to switch the service panel connection from main power to the generator and signal the generator to turn on. When main power is restored, the generator is turned off and then the transfer switch switches the power connection to the service panel 115 from the generator back to the main power 105. Most power outages are relatively short. However, an extended outage, such as the result of a major storm, can last days or even weeks. For extended outages, the possibility of running out of fuel before power is restored can become a major risk. In general, emergency backup generator systems give little concern to how long emergency power can be provided. While an estimated remaining generator run time may be provided, typically the onus is placed on the customer to control how much power is used and, thereby, how long the fuel supply is likely to last. In practice, the risk of running out of fuel is increased with large fuel tanks because an owner may not be proactive about keeping the tank full and so actual run-time will be shorter.

The expected run time of a generator is based on a variety of factors including the size of the generator and its efficiency, the type of fuel used, and the electrical load that is driven by the generator. A generator will typically have a known quiescent or idle fuel consumption rating. Estimates of fuel consumption rates are typically available for commercial generator models and indicate the average fuel consumption of the generator under one-quarter, one-half, three-quarters, and full load. This information can be used to determine how long a generator will run on a full fuel tank in various usage conditions. For example, a common 20kW propane fueled generator can provide enough power to run most systems in a typical 2000-3000 ft² house and consumes between 2 and 4 gallons of propane per hour depending on load. A 120 gallon propane tank will hold enough fuel for a 1-2 day outage while a 500 gallon tank can run the generator for 5-10 days. Various local and remote generator and fuel monitoring systems are available. These can provide estimates of runtime based on remaining fuel and a measure of power consumption and issue an alert when fuel runs low. U.S. Patent No. 7,360,529 discloses one technique for determining remaining run time by monitoring power consumption and fuel usage.

When a power outage initially begins, there may be little concern about conserving generator fuel and so facility systems might be kept on as they would be normally. However, as the power outage continues, the available fuel will dwindle. If a person on-site is monitoring the generator fuel they may try to save power by manually unplugging or turning off unneeded systems, such as various lights or personal electronics, while keeping critical systems powered as long as possible. One example of a critical system is a freezer used to store food or medicine that may be needed for survival of the facility’s occupants. Another example is an HVAC system that may be needed in extreme cold or heat conditions. Some facilities are designed to operate “off grid” and rely on a local generator to supply all of their power needs. In an emergency, it may be impossible to receive regular fuel deliveries. This situation raises the same concerns as those for a backup generator - ensuring that power remains available to critical systems for as long as possible.

Some generator systems can be provided with load shedding functionality. This feature allows lower priority loads to be temporarily disconnected (or “shed”) to make sure that a large power draw from a higher priority system does not overload the generator. The main advantage of load shedding is to allow the use of a smaller generator than would otherwise be needed to power all of the desired systems. While a smaller generator might use less fuel than a larger one (and so could run for longer on the same amount of fuel), the generator itself still remains on until the main power is restored.

If there is a backup generator, it can be used to power a refrigerator / freezer in the user’s home. The fact that temperature within a freezer may remain within safe limits for a period of time when the freezer is unpowered has been exploited to increase how long food can be preserved by turning the generator on and off periodically. While this process reduces the overall amount of time the generator is on relative to running continuously, merely cycling the generator does not allow for flexible generator control wherein power can be provided to a wide variety of devices in a house or other facility while also ensuring that operating requirements for critical systems can be maintained for at least a minimum targeted period of time.

SUMMARY

Disclosed herein is system for controlling a generator used to power a plurality of devices at facility, such as a backup generator used during a power outage. The powered devices include a critical device that operates to maintain a value of an operating parameter within a predefined standard range, and one or more non-critical devices. Device control modules are remotely controllable to connect and disconnect controlled devices from power or otherwise limit the power supplied to a controlled device or drawn by the controlled device.

A generator control (“GC”) module receives generator status data, such as an amount of fuel remaining, sensor data providing a measure of the value of the operating parameter, and can communicate with the device control modules.

During a power outage the fuel remaining for the generator is monitored. As the fuel level drops, device control modules can be signaled to reduce power used by their devices, such as by disconnecting them from power, thereby increase the remaining runtime of the generator. The system has multiple modes of operation in including one or more reduced power tiers and an extreme reserve (ER) mode of operation. Power reduction measures get more aggressive thresholds for reduced power tier are reached. A minimum remaining runtime or fuel threshold is set to define an ER mode (ERM) threshold for entering the ER mode. When the remaining capacity of the generator to provide power reaches the ERM threshold, the ER mode is entered. In this mode of operation, the generator is cycled on and off to provide power to the critical device as necessary to keep the operating parameter within a set range. When the critical device does not need to be powered, the generator is turned off to eliminate idle fuel consumption. The set range could be different from the normal range maintained by the device and different set ranges can be defined for use while in the ERM to further reduce fuel consumption.

Advantageously, this system and method allows flexible control of a generator to power a wide variety of devices in a house or other facility during a power outage while also ensuring that the operating parameter of the critical device can be maintained during an extended power outage.

In an embodiment, remaining capacity is determined based on at least one of a measured amount of remaining fuel and an estimated amount of remaining fuel; and tier and ERM thresholds can be defined with reference to the remaining amount of fuel. The remaining capacity is an indication of an estimated remaining runtime of the generator given current fuel supply and assumptions about future power usage, such as based on a power consumption profile of the generator and load of the circuit during the ERM mode of operation. The ERM threshold can be a time period, such as a number of hours, and where the ER mode is entered when the remaining capacity in hours reaches that threshold. In an embodiment, a user can specify a targeted minimum period of time that the critical device is desired to operate during a power outage. The system can set the ERM threshold to meet this target while also allowing various other devices to be powered by the generator for as long as possible before the ERM is entered. The ERM threshold can be dynamically adjusted relative to the target operating time set by the user to account for external factors that may, for example, impact the duration of the outage or scheduled fuel deliveries. In an embodiment, the ERM threshold is dynamically adjusted based on at least one of time of day, daylight or nighttime status and weather conditions.

In an embodiment, the system can determine remaining capacity based on a fuel consumption profile for the generator and data indicated expected power use in various conditions, low power tier modes of operation, and during the ERM of operation. The power drawn from the generator and fuel consumption of the generator over time can be monitored and used to determine the power consumption profile for the generator. A power consumption profile could also or alternatively be provided by default or retrieved from a remote location.

In an embodiment, the generator has a startup battery that is charged when the generator is running. The startup battery has a minimum charge below which the startup battery cannot restart the generator. The system monitors the charge status of the startup battery. When the system determines that the critical device does not need to be powered, if the startup battery charge is below the minimum, the generator is allowed to continue running until the startup battery is sufficiently charged, after which the generator is turned off. If the critical device is connected to power through a device control module, the device control module can be signaled to disconnect the critical device from power while the battery is being charged.

In an embodiment, a user interface is provided allowing a user to view and change various power tier thresholds and the ERM threshold. Such a user interface can be integrated or connected to the control module and/or accessed remotely, such as a remote computing device through one of a website and an API.

In an embodiment, the critical device is a refrigerator, freezer or heater, the operating parameter is temperature, and the ERM thresholds can be specified temperatures or functions based on temperature and other factors, such as how long a temperature threshold is exceeded and by how much.

In an embodiment, a sensor module is provided that receives sensor data and provides this to the generator control module using a wired or wireless interface. The sensor itself can be integrated within the critical device or separately added by the user. The sensor can be remotely coupled to the sensor module.

In an embodiment, a device control module is provided for the critical device. When the system is not in ERM, the generator control module can selectively connect or disconnect the critical device from power in accordance instead of cycling the generator on and off. In a further embodiment there are a plurality of critical devices, each of which is connected to a respective device control module and operates to maintain a respective operating parameter within a predefined range. The operating parameters of the critical devices are monitored. During ERM, the generator is turned off when the system determines, based on the values of the operating parameters, that all of the critical devices can be unpowered. If any critical device requires power the generator is turned on. For those critical devices where the value of their operating parameter indicates that power is not required at that time, the device control modules for such critical devices are signaled to disconnect those critical devices from power (or otherwise limit the power supplied to the critical device or drawn by the controlled device as may be appropriate).

In an embodiment, the sensor module can be integrated within the device control module. In an alternatively, the sensor module can be coupled to the device control module, such as by wired or wireless means, and the device control module used to relay sensor data to the generator control module.

In an embodiment, the generator control module is configured to poll the sensor on an intermittent basis to read data from the sensor. In an alternative embodiment, the sensor module is configured to transmit data to the generator control module on an intermittent basis. In a particular embodiment, the sensor is a temperature sensor, and the sensor module is configured to send data to the generator control module in response to at least one of the sensed temperature being greater than a maximum predefined temperature and the sensed temperature being less than a minimum predefined temperature.

In a further embodiment, the sensor module can be loaded with predefined sensor data transmission conditions, such when a sensed temperature exceeds a maximum temperature or is less than a minimum temperature, and configured to transmit data to the generator control module in response to a determination within the sensor module that the value of the operating parameter meets a predefined transmission condition. The predefined transmission conditions can be substantially the predefined ERM conditions used during generator cycling when in the ERM.

In yet a further embodiment, a device control module coupled to the critical device can be programmed with the predefined ERM conditions for powering the critical device and configured to selectively connect and disconnect the critical device from power based on the value of the operating parameter and predefined threshold conditions, such as the ERM conditions, when the system is not in ERM. That controller can also be configured to keep the critical device connected to the power line during ERM or operate to disconnect the critical device from the power line when it senses that there is no power available, such as when the generator is turned off, and to reconnect the critical device to the power line after sensing that the generator has been turned on or a predefined period of time after the generator has been turned on.

In an embodiment, the sensor module comprises a temperature sensor, the critical device is a refrigeration device, and the sensor module is either integrated within the refrigerator or removably placed in or on the refrigerator, e.g., by a user. In a further embodiment, the sensor is placed within the refrigeration device and connected by wired or wireless means to a sensor module exterior to the refrigeration device. In another embodiment, the critical device is an air conditioner or a heater and the value of the operating parameter is a measure of air temperature in at least one location. In yet a further embodiment, the sensor is part of a thermostat connected to the critical device.

In an embodiment, the generator control module is configured to enter the ER mode of operation in response to receipt of a manual ERM initiation signal. In an embodiment, the generator control module is configured to enter an ER override mode of operation in response to an ERM override condition and send a start signal to the generator if the generator is off, wherein the generator remains on during the ER override mode of operation, thereby permitting a device to be selectively powered during ER mode of operation without interference from generator cycling.

In an embodiment, the system returns to the ER mode of operation in response to the end of the ERM override condition. The system can also be configured to return to the ER mode of operation after a predetermined maximum override duration. The generator control module can be configured to disable the ER override mode of operation or block the override signal when the remaining capacity of the generator is below a predefined override cutoff threshold.

The override signal can be generated by an override switch or an override circuit that is remotely coupled to the generator control module or a device control module by wired or wireless means. The override switch or circuit can be within a housing configured to be hand-held.

In an embodiment, the override circuit comprises an IR or RF detection circuit responsive to signals from a separate device remote control. The override circuit is configured to detect a specified signal from the device remote control, such as a power on/off signal. In a further embodiment, the override circuit can be configured to broadcast a power on signal to a remotely controllable device, after the generator has been turned on in response to the override condition. In a particular embodiment, the remotely controllable device is a television and the device remote control is the television remote control.

In an embodiment, the override circuit has a unique ID and is configured to output a message indicating that the override switch has been activated, the message including the unique ID. The generator control module is configured to signal a device controller associated with the unique ID to connect its device to power when the ER override mode of operation is entered in response to activation of the override switch.

In an embodiment, the system comprises an override sensor connectable to a non-critical device that is connected to the circuit, the ERM override condition is initiated in response to a detection by the override sensor of an attempt to use the non-critical device. The attempt to use the non-critical device can be detected by sensing at least one of a change in load, resistance, inductance, and impedance on a power line connected to the non-critical device. In a particular embodiment, the override sensor is contained in a housing configured to clamp onto the power line connected to the non-critical device. In another embodiment, the override sensor is contained a device control module wherein the attempt to use the non-critical device is evaluated when the device is disconnected from the power circuit or power restricted and wherein the device control module reconnects the device to full power after detecting that the generator has been turned on during an ERM override state of operation.

In an embodiment, the override switch comprises a water level detection sensor. In an embodiment, the override switch senses water level in a sump pump.

In an embodiment, the device control modules each have a unique ID and can be independently addressed using the communication protocol.

In an embodiment, a device control module is configured to connect to a first power outlet on the circuit and has a second power outlet to which a non-critical device can be connected to receive power from the circuit. The device control module can be configured to selectively stop power from being supplied from the circuit to the second power outlet, reduce a power voltage at the second power outlet relative to a power voltage at the first power outlet, and/or limit the amount of power supplied to the second power outlet. In a particular embodiment, a non-critical device is a lighting system and the device control module, which can be integrated within the lighting system is configured to selectively dim the light to reduce power draw from the lighting device.

In an embodiment, the generator control circuit is configured to send an alert signal to a device control module prior to signaling the device control module to disconnect from power and the device control module is configured to output a user alert in response to receipt of the alert signal. In an alternative embodiment, the device control module can be configured to issue an alert signal after being instructed to disconnect from power and then disconnect the power after predefined period of time. The user alert can be a human perceivable audio and/or visual signal. The user alert can be a message sent over a communication network to a designated user. The user alert could also comprise a shutdown signal issued to a non-critical device connected to the device control module.

The system can be configured to associate each device control module with a power mode of operation, wherein when entering a power mode, such as a tier 1 or tier 2 mode, the device controllers for that mode are signaled to disconnect from power. Each device control module can have a unique ID and be independently addressable by the GC module, wherein the association between the device controller and power mode is maintained in a memory of the GC control module. In an embodiment, each device controller can be configured to respond to one more specified power modes in which the system can operate. The power mode for a device control module can be defined using a switch or user interface of the device controller. The generator control module broadcasts a current power mode to the device controllers and each device controller responds to disconnect from power in accordance with its defined power mode. In an embodiment, the system further comprises a transfer switch connected to the generator and to a primary power supply. The transfer switch is operative to automatically start the generator upon detection by the transfer switch of a loss of power on the primary power supply. The generator control module is connected to the transfer switch and signals the generator to start and stop through the transfer switch. The generator control module can be separate from or integrated with the transfer switch. In an alternative embodiment, when power does not need to be provided to the critical device, the generator can be disconnected from the service panel so all of the generated power can be used to charge the battery. When the battery is sufficiently charged, the generator can be stopped and the connection to the service panel can be restored.

In an embodiment, a system is provided for controlling a generator providing power to a refrigeration device. The generator has a fuel supply and is remotely controllable to start and stop. The refrigeration device operates to maintain a temperature of a chamber below a predefined maximum temperature. A sensor module comprises a sensor to measure the temperature in the chamber. A generator control module comprises a power supply and a programmed computer system. A device control module can selectively connect and disconnect a device to power in response to signals from the generator control module.

The generator control module has a plurality of increasingly aggressive power modes, including one or more power tiers and an extreme reserve (ER) mode of operation. The generator control module determines a remaining capacity of the generator based in received generator status data. It also monitors the temperature data provided by the sensor. Each tier has a trigger condition based on the remaining capacity. When the remaining capacity drops below the threshold for a given tier, the device control modules associated with that tier are signaled to disconnect power to a connected device. When the remaining capacity drops below an ERM threshold, the system enters an extreme reserve mode (ERM) of operation.

When in the ERM, the generator control module monitors temperature data from the sensor module. The generator is signaled to stop when temperature of the chamber is below a predefined ERM minimum temperature and the generator is signaled to start when the temperature of the chamber is greater than a predefined ERM maximum temperature. The ERM threshold can be dynamically determined or adjusted based on factors including operating conditions, ambient conditions within or external to the facility, and historic data. One or both of the predefined ERM minimum and maximum can be increased during ERM as the remaining capacity of the generator continues to drop.

In an embodiment, the refrigeration device is signaled to disable one or more sub-systems, such as ice maker or anti-frost heater, in response to a signal from the generator control module that the ER mode of operation has been entered. The sensor module can be integrated with the refrigerator in whole or part. The sensor module can comprise two separate portions, one with the sensor and that can be placed within the chamber, and one with circuitry to read the sensor and communicate sensor data and that can be positioned outside of the chamber. The sensor module can communicate the sensor data directly to the generator control module or can communicate sensor data to a relay in communication with the generator control module. In an embodiment, the relay can be a device control module connected between the refrigeration device and a power supply.

In an embodiment a system comprises a smart transfer switch that can selectively connect a power distribution panel for a facility between a primary power supply and a power from a backup generator. The transfer switch has a generator interface connectable to the generator and over which signals can be sent to the generator to start the generator and stop the generator. The transfer switch can receive fuel status and/or estimated remaining runtime from the generator. The transfer switch can also receive data indicating a value of an operating parameter of a critical device in the facility and that, when powered, operates to maintain the operating parameter within a predefined range.

A control module in the transfer switch operates in a plurality of operating modes including a normal mode, a backup operating mode, and an extreme reserve (ER) mode of operation. In the normal operating mode, the transfer switch connects primary power to the distribution panel. When a loss of power on the primary power input is detected, the control module enters a backup operating mode.

In the backup operating mode, a start signal to the generator and the distribution panel is connected to receive power from the generator. A remaining capacity of the generator is determined. When the remaining capacity is below a predefined ERM threshold, the extreme reserve (ER) mode of operation is entered.

In the ER mode of operation, the value of the operating parameter of the critical device is monitored. A stop signal is sent to the generator when the value of the operating parameter meets a first ERM predefined condition relative to a predefined control range and a start signal is sent to the generator when the value of the operating parameter meets a second ERM predefined condition relative to the predefined control range.

The ERM threshold can be one or more of an amount of remaining fuel for the generator, a percentage of remaining fuel for the generator, and a calculated remaining runtime of the generator. The ERM threshold can be dynamically determined or adjusted based on operating, ambient, and historic data. One or both of the predefined ERM minimum and maximum can be increased during ERM as the remaining capacity of the generator continues to drop.

A plurality of device controllers can be provided, each of which can selectively connect and disconnect a load to power. One or more intermediate power tiers entered into prior to ERM can be defined with reference to remaining capacity. Each device controller can be associated with a particular tier and signaled to disconnect its load from power when its power tier is entered.

DESCRIPTION OF THE FIGURES

Further features and advantages of the invention, as well as structure and operation of various implementations of the invention, are disclosed in detail below with references to the accompanying drawings in which:

Fig. 1 is a high level diagram of a prior art generator backup system;

Fig. 2 is a high level diagram of an embodiment of an improved generator control system;

Fig. 3 a high level diagram of a second embodiment of an improved generator control system;

Fig. 4 is a high level diagram of a third embodiment of an improved generator control system;

Fig. 5 is a high level schematic diagram of an embodiment of a generator control module;

Fig. 6 is an exemplary display of configuration and system monitoring information for an embodiment of an improved generator control system

Figs. 7A -7C are high level flowcharts of a method of operation of an improved generator control system;

Fig. 8 is a high level diagram of a generator control module integrated with a transfer switch;

Fig. 9 is a high level diagram of a multi-function device control module;

Fig. 10 is a block diagram of a control module and override system for use with remote controlled devices; and

Fig. 11 is an illustration of a critical device coupled with a sensor, a device control module, and an intermediate sensor booster.

DETAILED DESCRIPTION Fig. 2 is a high level diagram of an improved generator control system 200. A generator 125 with fuel source 130 provides electrical power 205 to a critical device 210 and can also provide power to one or more additional load devices 215.1, 215.2, ... 215. n, each of which can be a discrete device or plural devices connected to the same circuit or power outlet. The system 200 can be used with a backup generator system that operates during a power outage or a stand-alone systems, such as at an off-grid location. A generator control (“GC”) module 220 monitors the fuel available to the generator. As the fuel level drops, selected devices in the powered facility can be disconnected, provided with a reduced or limited amount of power, and/or allowed to connect to power and be operated only during a specified time or for a maximum duration. Reducing power demand on the generator 115 decreases fuel consumption over time. As the amount of remaining fuel drops, the power reduction steps become more aggressive.

Ultimately, system 200 enters an extreme reserve mode of operation (“ERM” or “ER mode”) When operating in the extreme reserve mode non-critical devices can be disconnected from power. The GC module 220 monitors the value(s) of the operating parameter(s) of critical device 210 and selectively turns off and on generator 115 as needed to maintain a status of the operating parameters within predefined ERM conditions, such as remaining within a first predefined range or not being outside a second range value for more than a maximum period of time. The targeted ERM conditions for the value of the operating parameter may differ from the standard operating range of the critical device under normal continuously powered conditions. Periodically tuning off the generator during the ER mode of operation saves substantially more fuel than simply turning the critical device itself on and off because it eliminates idle fuel consumption by the generator.

The transition point to the ER mode can be specified in a variety of ways. In one embodiment, a user can define an ER mode threshold based on a percentage of remaining fuel. In another embodiment, a transition threshold can be defined based on remaining runtime. In a particular embodiment, a user can specify a minimum period of time they want the critical device to maintain the operating state during an extended power outage. The system 200 estimates remaining generator runtime and dynamically determines the appropriate ER mode transition point(s) to reduced power tiers and the ER mode to meet the specified minimum time period. The resulting system 200 will thus allow the critical device operating state to be maintained for at least the specified minimum period of time while also flexibly providing power to other devices for periods of time prior to entering the ER mode.

In an embodiment, generator 125 operates as a backup generator to provide power when utility power is not available. For simplicity, a transfer switch that selectively connects local utility power or generator power to the load devices is not shown in Fig. 2. In a backup generator configuration, when a power outage is detected, the generator 125 is activated and the transfer switch will shift load from the utility power source to the generator. The system 200 can also operate in embodiments in which the generator 125 is the primary power supply, such as at a remote facility that is not connected to a utility power grid. In this embodiment a transfer switch to selectively connect to utility power or generator power would not be required. A critical device 210 can be one that functions under normal powered operation to maintain a designated operating parameter, such as a temperature, within a standard operating range and where the value of the operating parameter can remain within at least an emergency range for a period of time when the critical device 210 is not powered.

The GC module 220 is in communication with the generator 125 so as to allow the GC module 220 to start and stop the generator 125 on demand. The remote start connection to the generator 125 can be via a wired or a wireless connection. The signaling required to start and stop the generator is dependent on the configuration of the remote start functionality of the generator 125 and appropriate connections and control signaling will be known to those of ordinary skill in the art. For example, in an embodiment, GC module 220 can be configured to send a momentary start signal to start the generator 125 and a momentary stop signal to stop the generator 125.

Various ways to determine remaining runtime for a generator under various operating conditions are known to those of ordinary skill in the art. Where the intention is to allow the critical device to maintain its operating conditions for at least a minimum specified time period, a conservative runtime estimate can be used erring on underestimating the runtime available when in various operating states, such as one or more reduced power tiers of operation and then during the GC mode of operation. As the generator runs, GC module 220 monitors the amount of remaining fuel, either directly, such as by a fuel gauge reading, or indirectly based on known fuel consumption rates of the generator. GC module 220 estimates the remaining run-time of the generator given available fuel. More specifically, the GC module 220 can be configured to determine the actual or an estimated amount of fuel remaining in tank 130. Other data, such as power demand over time can also be collected. This information, combined with known, calculated, or otherwise estimated fuel consumption rates for the generator 125 under different loads allows the GC module 220 to estimate the remaining available runtime of the generator.

The amount of fuel remaining in tank 130 can be directly indicated by a fuel sensor 225 connected to the tank 130 and the GC module 220. Available fuel can also be determined by other means, such as indirectly by a fuel flow monitor 230 or by monitoring the load drawn from the generator and estimating fuel consumption based on the fuel consumption of the generator 125 under various loads as detailed in the generator specifications or as learned over time by monitoring the generator load and fuel consumption during operation. Some generator systems may include a fuel monitor and in such a configuration the GC module 220 can obtain fuel status via a communication link with the generator.

Generator fuel consumption rates for various makes and models of generators are conventionally provided by the generator manufacturer and typically indicate fuel consumption at least in the states when the generator is idling, and when it is at 50% and 100% of rated load. In an embodiment, during an initialization process, GC module 220 receives data indicating the model of generator 125 to which it is attached and rated fuel consumption rates for that generator 125. The generator model information may be available directly through the interface with the generator 125 to which the GC module is connected or this information can be provided separately, such as by an operator during an initialization process. Fuel consumption information may be available in a locally stored table of specifications for common generators, or retrieved by remotely accessing such information, such as via a remote internet web service.

In an embodiment, GC module 220 may also be configured to monitor the amount of power being supplied by the generator 125 over time and remaining fuel. This data can be used to learn the actual fuel consumption rates over time under various conditions at the facility. Where manufacturer provided fuel consumption specifications are available, those can be used initially for runtime predictions and the specifications refined over time within the system to allow for more accurate remaining run-time determinations. This data can also be used to generate fuel consumption vs load for the specific generator even if manufacturer specifications for this are not available.

As the generator 125 runs, the amount of fuel remaining, and therefore the remaining generator run time, drops. To extend the duration during which power can be provided to the critical device 210, an operator in the facility may manually turn off or unplug various other devices, such as devices 215.1, 215.2, to reduce the load on the generator and thus its fuel consumption. As discussed further below, in an embodiment, system 200 further comprises various device controllers that can be signaled by the GC module 220 to automatically disconnect, turn off, or reduce the power load of various devices in a staged manner as the available fuel supply drops to thereby reduce the load that needs to be powered by the generator 115. Even so, fuel consumption continues as long as the generator is active. To improve the accuracy of the remaining runtime determinations, the device controllers can also include conventional circuitry to measure the power drawn by various controlled devices over time.

The GC module 220 is configured with an ERM threshold value that indicates when the extreme reserve mode should be entered. This ERM threshold can be related directly or indirectly to the amount of fuel remaining or estimated remaining generator runtime. When the ERM threshold is reached, the GC module 220 will enter the extreme reserve mode of operation. Exemplary threshold values, such as 10% fuel remaining or an estimated remaining generator run time of 24 hours, can be predefined during an initial configuration process. The ERM threshold value can also be dynamically or indirectly determined based on a desired minimum period of time that a valid operating state of the critical device 210 should be maintained. For example, a user may specify a minimum period of 10 days in which they desire that the value of operating parameter of the critical device be kept within predefined ERM conditions. The required amount of fuel to operate the critical device for this period of time can then be estimated given known or estimated operating power requirements, and this information used to set an extreme reserve mode threshold value. The transition points for other power reduction states that precede the EM model can also be set in this manner. The ERM threshold can be adjusted as other loads on the generator are added or removed from the system 200.

In an embodiment, the ERM threshold can also be varied based on other factors which may impact the how frequently the generator may need to be run to power the critical device and, therefore, the estimated fuel consumption and remaining runtime. Such factors could include environmental factors including local environment and weather conditions, ambient temperature, time of day or year, location, whether the facility is occupied or not, etc.

For example, a freezer could maintain its internal temperature for a longer period of time if the ambient temperature is 50 F as opposed to 85 F and the estimated runtime adjusted accordingly. Such a freezer embodiment is discussed further below, including with respect to Fig. 3. The value of such static or dynamic additional factors can be obtained by or entered into the system 200 and their impact on power usage of monitored devices over time analyzed. This data can then be used as part of the remaining runtime calculations. In an embodiment, the ERM threshold can be dynamically adjusted based on an assessment or assumption about how long a power outage may last and/or whether scheduled fuel deliveries may be disrupted or refueling otherwise made more difficult. There are various ways in which this can be done and various factors that can be considered, such as geographic location, historical and current weather status, date and time, records of scheduled or expected fuel delivery dates versus actual delivery dates, etc. In an embodiment, a trained Al system can be used to provide predictive analysis based on relevant factors.

As an example, during winter in a snowy region it may be more likely that fuel deliveries will be disrupted and so the ERM threshold can be adjusted to have a longer targeted runtime in winter than in other months. This assessment can be refined by specific location. Certain areas in a region may historically experience greater snowfalls. An access road to a location may be one that is a high or a low priority to clear after a snowfall or is at a greater risk of being impassible due to flooding. In a further example, the system 200 can access external information sources, such as a website or radio signal, to determine if the area is under a state of emergency or a severe storm or other potentially disruptive event watch or warning. In such a case the ERM threshold can be dynamically increased to a longer target runtime. If data is available from the power company, such as through a website, giving estimated time for power to be restored, the ERM threshold can be adjusted accordingly. Likewise, the fuel delivery company may provide status indicating that fuel deliveries may be delayed.

In an embodiment, multiple ERM thresholds can be defined for use during different conditions and the ERM threshold used by the system 200 selected based on the conditions. The conditions can be the same as or different from those discussed above in the context of dynamically adjusting a single ERM threshold. For example, a user may define an ERM threshold for use during winter to have a longer target runtime than those for use during other seasons of the year. The base ERM threshold used would be selected based on time of year. The selected ERM threshold could be further adjusted based on other conditions as discussed above.

In an embodiment, an operator can also manually signal the system 200 to enter ERM. The ERM threshold(s) can also be varied on a time of day or other external factors, such as the weather. For example, ERM thresholds can be adjusted so ERM is initiated sooner during daytime where power for lighting is less critical. It will be appreciated that as conditions change, the system may automatically enter ERM and exit ERM. When in the extreme reserve mode of operation, the GC module 220 will turn off generator 125, cutting power to the critical device 210 (as well as to any other devices that remain powered by the generator 125). The GC module 220 monitors the value of the operating parameter of the critical device 210 via a sensor 235. With no power to critical device 210, the value of the operating parameter may change over time. If the value of operating parameter goes outside of a predefined range, which can be the normal operating range or a different emergency operating range, the GC module 220 reactivates the generator 125, restoring power to the critical device 210. When the generator 125 is turned back on, power to the critical device 210 is restored and it operates to bring the operating parameter back within a desired operating range. The GC module 220 continues to monitor the value of the operating parameter. When the operating parameter has been returned to a desired state, the GC module 220 turns the generator 125 off again and the cycle repeats.

The predetermined range can be discrete values, such as a minimum and maximum temperature, or values that depend on evaluating a function. In an exemplary embodiment, the operating parameter may be allowed to exceed a predefined range but only for a limited period of time. This time may be fixed or dependent on how far outside the predefined range the parameter is. For example, if the parameter is temperature, the threshold to reactivate generator 125 can be a degree-minute value where the further the temperature is above a predefined temperature, the sooner threshold value will be reached.

The operating parameter sensor 235 and GC Module 220 communicate using a wireless or wired connection. Sensor 235 may be configured to automatically provide the measured value to the GC module 220 on a periodic basis. For example, the sensor can broadcast the value periodically. Alternatively or in addition the GC module 220 may poll the sensor 235 at various intervals to read the currently sensed value or request that the value be transmitted. In yet a further embodiment, various threshold values for the operating parameter can be programmed into the sensor 235 and the sensor operative to autonomously signal the GC module 220 when the sensed operating parameter crosses a threshold, or when it crosses the threshold in a specified direction. The GC module and sensor 235 can each have a battery backup power source so that they can continue to operate even when the generator is turned off and no power is available. In another embodiment, the sensor is connected by wired or wireless means to a local device control module 240 that itself is in communication with the GC module 220 and can relay the sensor data. The type of sensor 235 that is used and its location is dependent on the type of critical device 210 and the operating parameter or parameters to monitor. For example, if the critical device 210 is a freezer, the sensor 235 can be a temperature sensor that indicates the temperature within the freezer. If critical device 210 is an air conditioner, sensor 235 may be a sensor that measures the temperature and/or humidity in a specific room. Various exemplary embodiments are discussed further below. While a single sensor 235 is shown, multiple sensors can be used to measure the operating parameter in different locations. The operating parameter may also be a combination of a plurality of different types of operating parameters. In addition, more than one device can be deemed to be a critical device and each has its own operating range. The generator can be turned off a determination is made that none of the critical devices need to powered at that time to maintain the relevant operating parameter. If one of the critical devices needs to be powered but another does not, power can be cut to the device that does not need it using its control module 240.

With further reference to Fig. 2, in a typical configuration, the generator 125 is used to supply power not only to the critical device 210 but also to various other load devices 215.1, 215.2, ... 215. n in the facility. System 200 can be further provided with various types of device control modules, such as modules 240.1, and 240.2. Each device control module 240.x is operative to control an aspect of a connected device in a way that allows for selective reduction of power use, directly or indirectly under control of the GC module 220, by a controlled device. The device control modules 240 are in communication with the GC module 220. The communication between a given device control module 240.x and the GC module 220 may be via a direct wired connection, a wireless data connection, or other means, such as a powerline data transmission over the facility’s electrical distribution lines. The communication interface may be the same as used to communicate with sensor 235 or different communication protocols can be used. Different control modules 240.x can use different communication means to communicate with the GC module 220.

One or more intermediate states or tiers of operation for the GC module 220 can be defined to activate at a specified threshold before or when the GC module 220 enters the extreme reserve mode of operation. Each device control module 240.x can be associated with a corresponding threshold. In one embodiment, during a configuration process each control module 240.x used in the system 200 can be assigned to a given tier and each tier has corresponding activation threshold conditions. As the generator runs and fuel is consumed, the thresholds for the various tiers will be reached and in response the GC module 220 signals relevant device control modules associated with that tier to enter or exit a power saving state as may be appropriate wherein power use is reduced. The tier activation thresholds can be defined in a manner similar to the extreme reserve mode threshold value or otherwise based on a direct or indirect measure of fuel or runtime for the generator 125. The tier activation thresholds can be predefined, can be set as a function of the extreme reserve mode threshold value, or independently specified. Certain control modules or tiers can also operate to disconnect power at the activation threshold but where power is periodically cycled on to allow connected devices to run for a period of time. A multi-stage configuration can be provided wherein below a second threshold the periodic power cycling is disabled so that connected devices remain off.

In an embodiment, the threshold condition(s) to enter and/or exit various tier operating modes can be adjusted by system 200 in a manner similar to adjusting the ERM threshold discussed above such that, for example, lower power operating modes can be entered sooner if conditions suggest that the power outage will be for an extended period and/or it may be difficult to refuel. Likewise, alternative tier activation thresholds can be defined for a given tier, with the particular threshold selected based on specified conditions. Returning to Fig. 2, one type of control module 240.1 connects between the power supply and one or more devices 215.1 and operates as a switch to reduce power used by a connected device by selectively connecting or disconnecting power to the connected devices 215.1 in response to signals from the GC module 220. Such a device control module 240.1 can have a standard connection allowing it to be plugged into a wall outlet and one or more switched outlets into which devices 215.1 can be plugged. Where plural switched outlets are provided, the outlets can be controlled so that all are turned on and off together or each outlet can be selectively turned on and off by the GC module 220.

A second type of device control module 240.2 can connect between the power supply and one or more devices 215.2 and comprises a power reduction circuit, such as current limiter, step-down transformer, voltage converter, resistor, or other mechanism that can be selectively engaged to reduce the amount of power and/or voltage supplied to a connected device 215.2 by a fixed amount or by a variable amount. Limiting the power draw can allow devices to remain in standby mode when they draw a small amount of power, but prevent the device from drawing larger amounts of power if use is attempted when not permitted. Reducing the voltage provided can be suitable for use with electronic components that can operate over a range of input voltages and where reducing the supply voltage reduces the power used. Examples include resistive devices such as an incandescent light and certain electric heaters. Different types of device control modules can be provided depending on the type of device that will be controlled. A device controller could also support multiple different power limiting features and the appropriate one for a connected device be configurable in a setup process. For devices that can be permitted to remain in a standby mode, a training session can be implemented wherein the power drawn during different operating states of the device can be monitored and this data used to set the maximum power permitted to be drawn in a low power state.

While device control modules 240.1 and 240.2 are discussed as being connected at the wall outlet, they can alternatively be configured to be connected at the service panel to control an entire circuit. In such a configuration, the device control module can selectively control power to all devices on the controlled circuit.

A further device control module embodiment can be provided that combines the functionality of device control modules 240.1 and 240.2 to allow power to a device or circuit to selectively be limited and/or reduced and selectively disabled under the control of GC module 220. Where a device control model has multiple power saving states, each state can be assigned its own activation tier.

Certain types of devices may include functionality that can be remotely triggered to force a device or system into a standby mode and/or prevent it from leaving a low power operating state. A device control module can include appropriate controls to interact with such a device, such as by transmitting appropriate control codes, to selectively place the device into a low power standby state and selectively allow the device to be fully powered up.

Some devices have settings that can be remotely changed via a WiFi connection or other wireless connection. The device can be remotely controlled by a device control module programmed to convert the control signals from the GC module into an appropriate control protocol for the device. It may also be possible to remotely control the device directly from the GC module. For example, a smart thermostat may be remotely configurable. The thermostat can be controlled to enable or disable the air conditioning or heating systems and to adjust the activation temperature set points consistent with the power operating mode in which the system is operating e.g, full power, a reduced power tier, or ECM.

In an example, two tier thresholds are defined in addition to the ERM threshold. The device control modules 240.x are each associated with specific tier or the ERM wherein they operate to reduce or disconnect power to a connected device depending on the tier. As the generator 125 runs, the tier 1 threshold will first be reached and the GC module 220 will enter the tier 1 mode of operation. In this mode, the device control modules 240 assigned to tier 1 are signaled to enter a power saving state.

As the generator 125 continues to run, the tier 2 threshold will next be reached and the GC module 220 enters the tier 2 operating mode. Control 240 assigned to tier 2 are signaled to enter a power saving state. Eventually, as the generator 125 continues to run, the ERM mode threshold will be reached and the GC module 220 will enter the extreme reserve mode of operation and the control modules 240 signaled accordingly.

A device control module 240 can be set by default to enter its lowest power state when ERM is entered. The operating state of a device control module 240 could be expressly defined for each operating mode. Alternatively, or by default, a control module assigned to a specific power tier will remain in the power saving state for lower tiers. If a control module 240 has multiple power settings, such as a reduced voltage or max power limit, and a power cut-off, each setting can be assigned a different tier. For example, such a control module 240 can be set to reduce the power supplied to a connected resistive load when tier 1 mode is entered and to disconnect power when tier 2 mode is entered.

While it is anticipated that in the various device control modules 240 will all be signaled to place their connected device into a low or no power state prior before the extreme reserve mode threshold is reached, one or more device control modules 240 could be assigned the extreme reserve mode threshold as an activation tier. In such a case, when the GC module 220 enters the extreme reserve mode of operation, any device control modules assigned to that threshold will also be signaled to enter power save mode.

The manner in which the signaling is sent to the modules can vary. In one embodiment, the GC module 220 can signal each control module 240 individually, such as by a unique control module ID. In another embodiment, the GC module 220 can broadcast an indication of the current operating mode or change of operating mode. Receiving control modules will respond to the broadcast tier in which the system is operating in accordance with the tier to which the control module is assigned.

In an embodiment, the GC module 220 is configured to issue a shutdown alert signal a period of time, such as 1 or 5 minutes, prior to turning off the generator when entering the emergency reserve mode to allow preparation for the shutdown, such as a controlled shut down of various equipment. In such an embodiment, the generator shutdown threshold can trigger the alert first and the generator shutdown signal be sent after a specified period of time has elapsed. Thus, for example, if such a feature is provided and enabled, upon entering ERM, the system may issue the shutdown alert and then delay for a predefined period of time before a generator shutdown is permitted even if the state of the critical device allows the generator to be turned off. Certain device control modules 240.x can be designated as having devices for which a pre-shutdown alert is desired. On entering ERM, a shutdown alert signal is sent and control modules 240.x without a shutdown alert designation can be signaled to disconnect power. After a predefined period of time, the shutdown alert designated control modules can be signaled to disconnect power.

In an alternative embodiment, the GC control module can signal entry into the ERM mode and defer turning off the generator for at least the predefined shutdown alert period of time. Control modules that are configured to disconnect power on entry into the ERM can disconnect power immediately while control module configured for use with devices that need a shutdown alert could delay disconnecting power for the predefined shutdown alert period and then disconnect power automatically. While shutdown alert functionality has been discussed herein in the context of entering ERM during which the generator may be turned off, similar shutdown functionality can be implemented to be triggered in response to entering other tier modes of operation, wherein when a particular device control module is assigned or configured to disconnect power on entry into that tier and is configured to issue a shutdown alert, the disconnection of power at that control module can be deferred by the predefined shutdown alert period.

In an embodiment, the sensor 235 and/or device control modules 240.x are configured to detect a shutdown alert signal sent by the GC module 220 and take responsive action. The critical device or other connected device, such as a computer, may support a remote shutdown feature and a responsive action comprises the sensor 235 and/or device control modules 240.x issuing an automatic controlled shutdown signal to such a connected device. In another embodiment, a responsive action is for the sensor 235 and/or device control modules 240.x to emit an audible or visible signal that will alert people that ERM has been entered and/or of the upcoming generator shutdown so they can take appropriate action. An alert signal can also be sent over a network to a smart device associated with a designated user, such as sending a text message to a designated phone number.

A generator will typically have a startup battery. The startup battery needs to provide enough power for the generator to start when a startup signal is received. The startup battery is charged while the generator is running. According to a further embodiment, when the system is operating in ERM, the determination of when the generator can be turned off includes consideration of the state of the startup battery. If the ERM thresholds for the critical device(s) indicate that the generator can be turned off, before the generator is turned off a further check is made to determine if the startup battery has sufficient charge to restart the generator. If the startup battery does not have sufficient charge, the generator is not turned off at that time. Instead, it is allowed to keep running until the startup battery charge status meets a minimum requirement, after which the generator can then be turned off.

A similar process can be used if there are other situations during which the generator needs to remain running during ERM even when the generator control system 220 determines it can be turned off until a generator maintenance condition is met. For example, there may be requirement that the generator be allowed to run without a load for a period of time to cool off.

Since there may be no need during the startup battery recharge and/or cool-down period to supply power to the critical devices, in a further embodiment, if power does not need to be supplied to any of the devices in the facility but it is determined that the generator needs to remain on for a period of time, the generator can be disconnected from some or all of the powered facility. This will reduce potential power draws and thereby the fuel consumption of the generator. There are various ways to selectively connect and disconnect a generator from the powered system. One option is to use a transfer switch. A separate circuit breaker could also or alternatively be provided between the generator and the facility and that can be controlled by the GC module.

The determination that the charge status of the startup battery is sufficient for a generator restart can be made using various techniques and different options may be better suited for different battery types and/or battery charging systems. The generator itself may have functionality that can provide the charge status information to the generator control system 220. The battery itself may have an battery management or battery monitoring circuitry integrated into or attached outside of the battery and that can provide an estimate of the state of charge for the battery. In an alternative approach, the voltage on the startup battery can be read directly. In some cases, the startup battery voltage while the generator is running will not provide an accurate measure of the battery’s current charge status. To address this, in a further alternative a voltage reading can be taken while the generator is being started up and the battery is under a startup load. A voltage that falls below a minimum value at that time can signal that there is at least a risk of the battery not having enough remaining charge for a second restart cycle. In such a case, the generator control system 220 can defer triggering a generator shutoff until the generator has been running long enough that the startup battery should have been sufficiently recharged. The charge status of the startup battery is thus based, at least in part, on the runtime of the generator. Specifications for the startup battery and the rate of charge by the generator can be used to estimate a recharge rate and time period. In yet a further alternative, a default minimum run time for the generator can be set and the charge state of the startup battery presumed to be adequate if the generator has been running and charging the startup battery for at least the minimum period of time.

During ERM, when all but critical devices may be disconnected from power, there may still be a desire to use an unpowered device. To accommodate this, a manual override switch can be provided. Activating the switch signals the GC module 220 to enter an ER override mode of operation during which the generator 125 is turned on even if it is not presently needed to maintain the value of the critical device operating parameter. The generator can remain on until the override is manually ended or remain on until another override end condition is met, such as an expiration of a period of time. The manual override switch can be contained within an override module that also includes a wireless communication interface to signal the GC module when the switch has been activated. The module can be contained in a housing with an externally accessible button. Pressing the button activates the override. In an alternative to a physical button, the manual override can be controlled remotely, such as through a radio or optical interface. A control module 240 can be selectively designated as one that will power a device during an override period. During an ER override mode of operation, such a control module can be configured to switch power on for a connected device during the override period and then disconnect from power when the override period is ended.

Analogous functionality can be implemented to allow an override of a power disconnect state of one or more selected control modules in operating modes outside of the ERM to selectively cause the control module to reconnect its device to power. If the override functionality is intended for use during periods when the generator is not cycling (i.e., in modes other than ERM), the override functionality could be implemented wholly within the control module itself and without having to signal the GC module 220 that an override is desired.

Fig. 9 is a high level block diagram of a control module 900, which is a multi-function embodiment of control module 240. Control module 900 has a housing 902 that encloses various components of the control module 900. Module 900 can be connected the power supply using a conventional plug 904 that engages a wall socket. Module 900 has one or more outlets 906 to which the devices to be controlled can be connected. Internal control circuitry 910 is connected to a switch 914 that operates to selectively connect and disconnect the outlet 906 from power 904. If there are multiple outlets 906, each can be coupled to the same switch or each outlet or outlet group can be connected to separate switches, which in an embodiment can be independently controlled by control circuit 912. Alternatively, or in addition, switch 914 can function to reduce the amount of power that is made available to a connected device, such as for example limiting the maximum number of amps that can be drawn so a device can remain in a standby state but be prevented from drawing full power if turned on during a period when use that the device is not permitted.

The control circuitry 910 can comprise a conventional microcontroller or microprocessor driven system. The control circuitry 910 is coupled to communication circuitry 912 that supports a wired or wireless communication protocol to allow data communication with the GC module. More than one protocol can be supported. The communication circuitry 912 can be separate from or integrated in whole or part in the control circuitry 910 and comprise one or more wired or wireless methods of communication. Communication circuity 912 and/or microcontroller 910 can also include circuitry for communicating with one more sensors, such as a thermometer, to receive sensor readings. Separate sensor interface circuits could also be included.

The control module 900 needs to function when no local power is available, e.g., when there is a power outage and the generator is off. Accordingly, the control circuitry 910, communication circuit 912, and other functions can be powered by a battery 922 when wall power is not available. A charging circuit (not shown) can be provided to charge the battery 922 when wall power is available. Likewise, the communication protocol used for communication with the GC module should be operable on battery power during times when the generator is off. Various suitable low power microcontroller / microprocessor systems and communication channels and protocols are known to those of ordinary skill in the art. Control modules of different complexity and with different features can be provided depending on intended use and on the type of device for which it will be used, including whether the control module is intended for use with a critical device. Certain functionality of the control module 900 can be turned off or disabled when running on battery power to reduce power consumption.

Control module 900 can include a user interface 920 to allow a user to check status and/or configure one or more settings for the control module 900. Interface 920 can include a display and keyboard, keypad, touchscreen or other method of user control. Alternatively or in addition, some or all of the settings can be remotely configurable through the GC module or an external device, such as a smartphone, PC, or tablet via an App that can communicate, e.g., over bluetooth or WiFi, with the module 900. In a particular embodiment, interface 920 comprises one or more selectors through which the user can define various settings. For example, if system 200 has a defined number of power tiers, such as three, in addition to GC mode, the switch can be used to specify which of tiers 1, 2, or 3 the particular control module 900 is in. A critical device setting may also be provided. Other options, such as enabling shutoff alert, may also be selectable.

Control module 900 may be provide with an override switch 930 through which a user can initiate an override as discussed below. Override switch 930 can be a physical switch or one that can be triggered through a wireless signal, such as an RF or optical signal from a separate controller. Switch 930 can be integrated into the housing 902 of the control module and/or connected through an external connection so that switch 930 can be positioned separately from the control module 900. Where an override option is available, an output indicating the time remaining for the override can be produced. The remaining override time can be output on display 920 and/or on a separate external display 940 which can be positioned separate from the control module 900. So, for example, a user may want to be able to trigger a power override so they can use their stove. The control module 900 may be positioned behind the stove while the override switch 930 is positioned where a user can reach it easily and display 940 is positioned where it is easily visible.

In a further embodiment, an override sensor can be connected to a specific device and coupled to an override module. The override sensor is used to detect when there is a power demand associated with the device. When the demand is detected, the override module can signal the GC module of the power demand condition. In response, the GR module 220 can turn on the generator and keep the generator on until a specified condition is met, such as elapsing of a period of time or a detecting that power is no longer being demanded from the device, e.g., it has been turned off. For example, for various types of devices, even when no power is being supplied activating the device power switch will cause a measurable change on the power line connected to the device, such as a change in the line load, resistance, inductance, impedance, etc. Detection of this change indicates a power demand and can be used to signal the GC module 220 to turn on the generator 125.

In an embodiment, the override sensor can be in a module integrated within the device that can detect when the device is turned on. Power demand can be detected indirectly or directly, such as by detecting when an “on” switch is flipped or when an “override” button is pressed. Alternatively, the override sensor can be part of a separate override sensor module (not shown) and which can be connected by a user to the device. The override sensor module 242 can be linked to the GC module 220 in a manner similar to that used for device control modules 240 and can include circuitry to detect a device power demand and/or a user selectable override switch. In a particular configuration, the override sensor is contained in a housing configured to clamp onto the power line of the non-critical device that plugs into a wall outlet or other power source.

In one embodiment, an override sensor can be configured to plug into a wall outlet and have a power outlet that the device can be plugged into and through which a power demand from the device can be detected. The override sensor can be configured so that when power is being supplied, the power simply passes through to the device outlet. However, when power is not available, the sensor circuitry operates to decouple the device from the power circuitry of the facility. Isolating the attached device in this manner may make it easier to indirectly detect a power demand.

Similarly, for a device control module that is limiting power supplied to a device to that needed for a standby state, an attempt to turn on the device may be detectable by monitoring the power demand for changes consistent with a power on attempt. For example, limited power can be provided to an electric range to allow the control circuitry to remain active but not to power a heating element. When a user turns on a heating element, the range will try to draw more power than the device control module will allow. This change can be detected. The device control module can then provide full power if use of the device is allowed at that time. The usage detection can be treated as an override signal wherein if the system is in ERM and use of the device is allowed, the generator will be turned on if needed and power cycling of the generator deferred during the override state.

An override sensor can be integrated with or separate from a device control module. An override module can be assigned a unique ID that is included in the override switch activation signal to the GC module. The override module ID can be associated with specific sub-circuits or devices and the GC module operative to selectively connect power to those associated sub-circuits and/or devices during the override mode of operation.

A particular implementation of an override system is configured for use of a device that is responsive to a conventional IR or RF remote control, such as used for a television, and where detection of an “on” signal from a remote control is an indication of a demand for power. Fig. 10 is a high level diagram of a control module and override system for use with such a system. A control module 1000, which is analogous to the control modules discussed previously, is used to control power input to a device 1002, such as a television, which can be turned on using a remote control 1004. A manual override module 1010 includes an IR or RF detector 1012, as appropriate for the type of remote control at issue, and an emitter 1014 that can output signals to control device 1002. The manual override module 1010 can include a housing which is suitable to be placed in the vicinity of a television or other device for which the remote control is to be used and comprises a battery, and circuitry to detect and identify one or more signals from the remote and to generate output signals using the protocol recognized by the device 1002. Conventional techniques known to those of ordinary skill in the art can be used as needed to configure the override module 1010 to be responsive to the particular remote control protocol at issue and to emit control signals.

The override module 1010 is in communication with control module 1000 and/or the GC module, through a wired or wireless interface. When the override module 1010 detects an “on” signal from the remote control 1004, it signals the control module and/or GC module to initiate an override so that power is available for device 1002. Once override is in place and the device 1002 is powered, the override module 1010 emits appropriate control signals through emitter 1014 to turn on the device 1002. While the emitter 1012 and detector 1014 are shown in a single device 1010, the emitter and detector can be separate from each other so that they can be placed in different locations.

While the embodiment of Fig. 10 is specifically useful to detect when a user wants to power on a device that is designed to be operated using a remote control associated with a device, such as a television, in alternative embodiments, the remotely controllable manual override system can be used to override the ER mode to provide power to other user devices or circuits. A dedicated remote control may be used.

In another example, the need to supply power to one device can be signaled by a change in condition of a separate device. By way of example, a below-ground toilet may require a sump pump to transfer waste water into a septic system. A sensor, such as a float switch, can be used to detect when the toilet has been flushed or when water in the system reaches a level that the pump needs to be activated. An inductive coupler, such as a snap on winding of wire on a ferrite form on the pump motor power source wire could be used to detect when the motor has been connected to power, such as by a motor activation float switch in the sump pump system. In response, the GC module 220 turns on the generator 125 to provide power to the sump pump while needed, such as until the float switch state indicates that no more water needs to be pumped out. Instead of a float switch, the need to power the sump pump can be detected other ways, such as by detecting a drop in the water in the toilet tank, or even detecting the sound of a flush.

In some instances, even if the generator is active, the device may be on a circuit that has been disabled as part of pre ERM power saving tiers. Detection of an override signal or a power demand for the device can be used to signal the GC module 220 to temporarily activate that circuit or to signal the appropriate device control module to connect its controlled device to power. While such an override system can be used to signal the GC module 220 to turn on the generator to provide power, e.g., to a non-critical device, the conditions where such an override is permitted may be limited. For example, an override that results in the generator being turned on may be permitted when the system is in an early stage of ERM but not permitted in a late stage ERM when remaining fuel or runtime is further depleted. Such an override disable threshold can be device dependent so that overrides for devices that consume a lot of power are disabled before overrides for devices that only consume a small amount of power.

In an embodiment, the system can be configured with one or more operating tiers in which all critical and non-critical controlled devices can be disconnected or put into low power state and the device only activated when a demand for its use is detected and use of the device is permitted at that time. During ERM, disconnecting all devices by default, even critical devices, can allow devices to be powered on in a staged process to reduce power surges and to ensure that power is provide only to designated devices. Remaining disconnected by default can also give time for the generator output to stabilize before a device that should be powered on is connected to power. Even outside of ERM, a default setting can be to disconnect all controlled devices and only enable them when a demand for their use is detected, such as by detecting an attempt to power on or wake up a device, or in response to an override signal, or, for a critical device, when the device needs to be powered to maintain the operating parameter value. Enabling of devices can be further restricted by factors such as the tier of operation, time of day, prior duration of use, etc. If use is not permitted, an output can be generated, e.g., through the device control module, with an indication that use has been blocked. Further information, such as why the use has been blocked and when use is permitted, can also be output.

In an exemplary embodiment, and with reference to Fig. 3, the critical device 210 is freezer 305 that can be stocked with food. In a disaster scenario where municipal power is out for an extended period it may be critical that such food remains frozen to allow for long duration storage while remaining safe to eat. A temperature sensor module 310 is associated with the freezer and is in communication with the GC module 220, such as by a wireless or wired interface. In one configuration, a temperature sensor module 310 comprises control circuitry (which may be a programmed microprocessor connected to data and program storage), a communication interface 315 for communication with the GC module 220, a temperature sensor 320 that can be positioned within the freezer 305, and an independent power supply (not shown). The entire module 310 can be configured to be placed inside the freezer 305. If the construction of freezer 305 does not allow the sensor module 310 to communicate with the GC Module 220 through the freezer wall, the sensor module 310 can be configured as physically separate components wherein the temperature sensor 320 can be placed within the freezer 305 and at least a portion of the communication interface 315, such as an antenna, positioned outside the freezer housing. The remaining components of the sensor module 310 can be located either inside or outside of the freezer. In an alternative configuration, the temperature sensor and an interface allowing communication with the GC Module 220 is integrated within the freezer 305.

In the system 300 of Fig. 3 power is normally provided from the local utility 105 and passes through transfer switch 350 to a distribution panel 115 and therethrough over one or more circuits to provide power to the freezer 305 and other devices 215.1, 215. n. When a failure of the utility power is detected, the transfer switch 350 operates to shift the load to the generator 220. In an embodiment, the GC module 220 is operative to detect the power outage, for example by means of a signal provided by the transfer switch 350 or a separate line monitor, and in response turns on the generator 125. Alternatively, the transfer switch 350 may itself operate to initially turn on the generator 125 in an initial response to a power outage. The GC module 220 can subsequently and independently turn the generator off and on.

During the power outage, the GC module 220 will monitor the remaining fuel and/or runtime of the generator as discussed above and will enter the extreme reserve mode of operation when that threshold is reached, at which point the GC module 220 will cycle the generator on and off to maintain the temperature in the freezer within the defined extreme reserve mode range of temperatures.

A typical home freezer is set to maintain an internal temperature of about 0 F (-18C) during normal operation. While the generator 125 is off, the freezer temperature will slowly rise. The GC Module 220 monitors the temperature of the freezer to detect when the temperature reaches a predefined maximum temperature for the extreme reserve mode operation such as 30F (-1C). When this threshold is reached or exceeded, the GC module 220 turns the generator on. The predefined ERM maximum temperature can be set by default and/or set or modified by a user during a system configuration process. With the generator 125 on, the freezer 305 is powered and the internal temperature drops. The temperature is monitored to detect when it reaches a predefined ERM minimum value, which can be the normal set temperature of OF or another predefined value used in the extreme reserve mode. For example, studies have shown that, such as 5F or 10F, which values can also be set by default and/or by a user. The generator 125 is then turned off and the cycle repeats. In a variation of this embodiment, the GC module 220 may require that the internal temperature be at or below the predefined minimum for at least a set period of time before the generator is turned off again. This allows for the temperature to equalize within the freezer to avoid local ‘hot spots’.

Freezer 305 can be a stand-alone freezer or a conventional refrigerator / freezer combination. In an embodiment, the sensor module 310 may measure the temperature of the both the freezer and the refrigerator and the GC module 220 be operative to power the generator on an off in order to keep both the refrigerator and freezer sections with defined ERM operating thresholds. The sensor module 310 can also be configured to disable features of the freezer 305 in response to a signal from the GC module 220 that the emergency reserve mode has been entered. For example, the freezer 305 may have an automatic ice maker or be equipped with an anti-frost and/or an “anti-sweat” heater that cycles on and off to keep condensation off of the interior and exterior, respectively. Disabling this equipment can substantially reduce the power consumption by the freezer 305. Instead of being signaled through sensor module 310, the freezer 305 may be signaled directly by the GC module 220 to enter a power save mode of operation. Such remote control may be provided through a WiFi or bluetooth connection available on a “smart” freezer system.

In a further exemplary embodiment, the critical device can be a deep freeze or refrigerator containing, for example, medical samples or medicines which must be stored at or below a specific temperature, such as -20F (-30C) or 35F (2C). The samples or medicines may remain viable at higher temperatures but only for a limited period of time. The system can be configured so that the generator is reactivated if the freezer temperature is above a predefined threshold value temperature, such as 10F (-12C), for more than a set period of time or if the freezer temperature reaches a predefined maximum, such as 20F (-7C). The system can also or alternatively determine when to cycle the generator off and on based on a degree-hour calculation relative to a predefined value and wherein the generator will turn on when the degree-hour total reaches a predefined maximum.

In yet a further exemplary embodiment, and with reference to Fig. 4, the critical device is an air conditioner 405 that provides cooled and/or dehumidified air to one more areas, such as rooms 410.1, 410.2,... , 41O.n. One or more temperature sensing modules 415 in communication with the GC module 220 are used to monitor temperature in one or several locations and provide that data to the GC module. For example, each room can have an associated temperature sensor 415.1, 415.2,... , 415. n. The GC module 220 receives the temperature readings and operates to cycle generator 125 on and off in a manner similar to that of the freezer system to keep the sensed temperature within an ERM range. The temperature thresholds used can be based on the measured temperature in one location or the temperature in several locations, for example to maintain an average temperature, to power the generator so that none of the monitored temperatures exceed a maximum threshold, or to meet other specified temperature requirements.

In a particular embodiment, the sensor may be integrated within a smart thermostat used to control the air conditioner system during normal operations. In such a configuration, there may be a central smart thermostat that collects temperature data from multiple remote thermostats and the GC module 220 can obtain the temperature data by communication with the central smart thermostat instead of directly from each separate thermostat.

Alternatively or in addition, humidity sensors can be provided to measure the humidity at one or several locations and the GC module 220 configured to cycle the generator 115 on and off to keep the measured humidity within a predefined range. Human tolerance for high temperatures is impacted in high humidity environments because the efficiency of evaporative cooling from sweat is reduced. In an embodiment, the threshold values used by the GC module 220 to cycle the generator 115 on and off can be heat index values that are functions of temperature and humidity.

In another exemplary embodiment, the critical device is a heating system and the GC module 220 is configured to maintain a minimum temperature in one or more locations within a predefined ERM threshold. In a variation, the GC module 220 is configured to cycle the generator and provide power to various HVAC components to run heating or cooling systems as needed to maintain the measured temperature within predefined ERM range(s).

In some situations, more than one critical device 210 may need to be driven by the generator 125. Each critical device will have an associated operating parameter that should be kept within a defined range of values. In one embodiment, the GC module 220 monitors the operating parameter of each critical device. If the operating parameter for each of the critical devices is within the specified operating range for the extreme reserve mode of operation, the generator 125 can be turned off by the GC module 220. The generator 125 is turned on again when the value of the operating parameter for any of the critical devices 210 moves outside the respective extreme reserve mode operating range.

Although a critical device can be controlled by generator cycling, during ERM, a critical device can also be coupled to a respective device control module 240.x that can selectively cut the power supplied to the attached critical device under control of the GC module 220. The GC module 220 monitors the value of the operating parameters for the critical device. For a given critical device, the GC module 220 can signal the associated device control module to cut power for that critical device during selected non-ER modes of operation if that critical device’s operating parameter is within a specified operating range, and to restore power when the value of that operating parameter moves outside the operating range. The operating range can be the same as the range used for the extreme reserve mode of operation or a different range.

A control module used with a critical device can also provide additional functionality. With reference to Fig. 11, freezer 305 is coupled to power through a control module 240’. The sensor 230 can be coupled to an intermediate booster 312 through wired or wireless means. Booster 312 is in communication with control module 240’ through wired or wireless means. Control module 240’ can be configured to serve as a relay to provide the sensor data to the GC module 220 using the communication link that already exists.

More than one critical device can be controlled, each connected to a respective control module. During ERM The GC module 220 monitors the value of the operating parameters for the critical devices. For a given critical device, the GC module 220 signals the associated device control module to cut power for that critical device if its operating parameter is within the specified operating range for the extreme reserve mode of operation and to restore power when the value of that operating parameter moves outside the respective extreme reserve mode operating range. When the values of the operating parameters for all of the critical devices is within the specified operating ranges, the generator can be turned off. The generator is turned on again when the value of the operating parameter for any one of the critical devices moves outside its specified operating range.

Fig. 5 is a high level schematic diagram of an embodiment of a GC module 220. GC module 220 comprises a programmed computer system with at least one processor or microcontroller 505 and a digital storage medium 510 for storing computer software 515 that controls the operation of the processor, sensor and operating status data 520, and system configuration information 525. A power supply 530 is provided which can include a battery so the GC module 220 can operate when external power is not available.

One or more interfaces 540 allow the GC module 220 to communicate with external devices. Interfaces 540 can include an interface 540.1 to communicate with the Generator to turn it on and off and, if supported by the generator, to retrieve generator status information which may include fuel status and load. Fuel sensor 540.2 provides communication with a fuel sensor 225 to obtain information about the available fuel. Sensor interface 540.3 provides communication with the sensor module 235 to obtain information about the value of the monitored operating parameter(s) of a critical device 210. Interface 540.4 provides communication with device control modules 240 that may be present in the system. Transfer switch interface 540.5 provides communication with a transfer switch as may be needed, e.g., for the GC module 220 to receive status of the utility power supply. Depending on implementation, the signals to turn on and off the generator may be routed through the transfer switch via the transfer switch interface 540.5 instead of being sent through a separate generator control interface 540.1. While multiple separate interfaces 540.x are shown, one or more can be combined into a single interface depending on the various communication protocols used. For example, communication with the critical device sensor 235 and device control modules 215 may all be through the same wireless protocol, such as WiFi, Bluetooth LE, or Z-Wave. Implementation of the various mechanisms for such communications are known to those of ordinary skill in the art.

Network interface 545 provides a communication path that allows a user to access the GC module 220 for purposes of, e.g., an initial configuration, adjustment of various thresholds, monitoring operating status, updating internal software, and for other purposes. The network interface 545 can be a wired or wireless internet connection, a cellular data link, or other connection to a network, such as a LAN, WAN, or the internet. In a particular embodiment, GC module 220 is configured so that such remote access is available via conventional internet browser software or a App that can be run on a smart device, such as a smart phone or tablet computer. The network interface 545 can also be used by the GC module 220 to retrieve from a remote server or network service information about various system components, such as relevant operating and power specifications and available functionality of the generator 125 and critical device 210.

Fig. 6 is an exemplary configuration and system monitoring display 600. The display can present various information including System Configuration 605, extreme reserve mode and various device control module thresholds 610, critical device thresholds 615, and system status, 620. During an initial system configuration a user can be prompted to enter information in the System Configuration window 605 about the generator make and model, size of fuel tank, type of fuel the generator being used. Available device control modules 240 can also be listed and the user prompted to assign each to a tier. A default tier can be assigned. For example, device control modules 240 can be triggered by default when the extreme reserve mode is entered. In an embodiment, the GC module can be configured to automatically detect any device control modules that are connected within the facility and list them. In embodiments where the available amount of fuel is determined indirectly, such as when this information cannot be obtained by remote monitoring of a generator fuel gauge, a user may also be prompted to enter a starting amount of fuel available. Configuration data used by the GC control module 220 can also include data indicating a maximum amount of fuel that can be available to the generator at any given time and provide a mechanism to reset the available fuel value to this amount upon an indication that the fuel tank has been filled.

Various threshold values can be input in the Mode Threshold window 610. In an embodiment, the user may be allowed to enter a threshold using various measures, such as runtime remaining or percent or amount of fuel remaining. Other thresholds can also be references. In the example of Fig. 6, the ERM threshold is 48 hours, the tier 1 and tier 2 thresholds are when the remaining fuel is at 75% and 50% of capacity, respectively, and the Tier 3 is triggered when extreme reserve mode is entered. The various tiers can be assigned default settings that a user can alter. If sufficient information is available, the system may allow entry of either of the measures for a threshold and then calculate and display the alternative measure. E.g., if a user specifies 50% remaining fuel, the estimated runtime for that amount of fuel can be displayed and visa versa.

The Critical Device Threshold window 615 is used to define when the generator is turned on and off. The thresholds can be populated with initial default values selected based on the system configuration. Different types of thresholds may be listed depending on the type (and number) of critical devices. For example, if the critical device is a freezer, predefined ERM maximum and target temperatures can be initially assigned and altered by the user.

The system status window 620 provides current system information, such as the amount of remaining fuel, estimated runtime (which can be based on average power use over a set interval, such as 1 hour, 12 hours, or other period) and the value of the critical device operating parameter(s). Operating mode information can also be displayed, such as whether the generator is on or off, if the system is running in ERM mode, and whether any of the device control module tiers has been triggered.

In an embodiment, a remote management system accessible over the internet is provided and allows a user can register their GC module device and enter at least some of the configuration information, such as the generator make and model, size of fuel tank, type of fuel, and the critical device make and model. As the user enters basic configuration details, relevant operating and power specifications and available functionality can be retrieved and stored a user account configuration database. The configuration information can subsequently be downloaded to the GC module 220, e.g., through the network interface 545. Similarly, existing configuration information stored in the GC module 220 can be uploaded to the management system and stored in the user’s account configuration database.

System configuration, threshold, and status details, such as illustrated in displays 605, 610, 615, 620, and other information collected or generated during operation can be stored in one or more tables or other data formats in the memory 510. Such other information can include current generator and fuel status and sensor readings and historic values over time, calculated values, such as average power demand and estimated remaining run times, and the state of various trigger events and flags, such as the current mode of operation and whether any defined device control module activation tiers have been triggered.

Figs. 7A - 7C are high level flowcharts of a method of operation implemented by the GC Module in the configuration of Fig. 2. During an initial setup and idle process, the system is configured, such as discussed above with respect to Fig. 6, and the configuration details are stored (step 702). Once the system is configured, the system operates in a standby state during which utility power input is monitored to detect a power outage (steps 704, 706). The GC module can monitor the power input directly or indirectly, such as through signals from the transfer switch. When there is a power outage the transfer switch is toggled to connect the generator to the load (step 708) and the generator is turned on (step 710). The system then transitions to a main generator control process. Depending on implementation, one or both of the steps 708, 710 may be implemented in the GC module 220 or the transfer switch. In some auto-changeover implementations, a separate system might initially toggle the transfer switch and startup the generator.

During the power outage, the remaining fuel status for the generator is determined or estimated (step 712) and one or more estimates of the runtime remaining can be made, depending on the conditions used to transition between different tiers and ERM. (Step 714). In an embodiment, an estimate can be based on a expected average power consumption in one or more modes mode of operation, which estimate can be based on factors such as historic data and measurements of power usage during a recent time interval. For example, a runtime estimate can be made for scenarios including running at maximum power, estimated power use in various low power tiers, and an estimate during ERM.

The system then determines if various mode transition thresholds have been reached. In the flowchart, two tier power mode thresholds and the ERM threshold are illustrated. As discussed above, transition thresholds can be based on a quantity of fuel, estimated remaining runtime(s), and/or other factors. If the first power reduction tier threshold has not been reached (step 716), the system can enter a maximum power state (step 718) during which all of the device control modules 240 can be set to power connected devices. If the tier 1 or tier 2 thresholds are reached, the system enters the corresponding tier 1 or tier 2 power operating modes. (Steps 720, 722, 724, 726). If the ERM threshold is met (step 728), the extreme reserve mode of operation is entered (step 730). The system continues to monitor fuel status and check thresholds and transition between modes as appropriate. While 2 tiers are shown in the flowchart, more or fewer tiers can be used. At a minimum only the ERM threshold check is performed.

Fig. 7B is a simplified flowchart for controlling power settings during various power modes. This function can be called from the main loop each time a determination is made about which power is active. Alternatively, the function can be called only during transitions from one mode to another. In a particular power mode X, such a max power, a defined tier, or ERM, the power settings for that mode are accessed (step 732). The device control modules are signaled as appropriate to connect, disconnect, or otherwise modify power to available to their connected device(s). (Step 734). The function can then return to the main loop (step 738). In an alternative implementation, instead of returning to the main loop after the device control modules are signaled, the conditions can be monitored to determine whether the conditions remain within the requirements for that power mode. If the conditions are no longer present, control can then return to the main loop where the appropriate mode of operation is determined. Additional control features to implement override functionality can be included as well.

Fig. 7C is a simplified flow chart illustrating critical device control functionality for a critical device. In this example, the critical device is a freezer, however, the method is applicable to other critical devices. The current temperature of the freezer is obtained (step 740). Depending on the implementation embodiment, this may require querying the sensor to request a current temperature reading, waiting to receive a next periodic temperature report from the sensor, reading a stored temperature in memory (e.g., where a separate program thread independently receives and stores sensor data for later reference) , or if the threshold values are programmed into the sensor, checking to see if the sensor has signaled that the temperature has passed a defined threshold value. If the system is operating in ERM (step 742), the system cycles the generator on and off. ERM threshold checks are made, with the threshold checked dependent on whether the generator is on or off. If the generator is on (step 744), a check is made to determine if the temperature is less than the ERM minimum (step 748). If it is, the generator is turned off (step 750). If the generator is off (Step 744), a check is made to determine if the temperature is greater than the ERM maximum (step 752). If it is, the generator is turned off (step 754). The freezer temperature is then checked again and the loop repeats.

In an embodiment, the freezer can be controlled outside of ERM to reduce power consumption as well. This function can be optional and something that a user could enable or disable. If the feature is available, when the system is not in ERM (step 742), a check is made to determine if the freezer temperature is less than the minimum for that operating mode (step 756). If it is, the freezer device controller is signaled to turn off and disconnect the freezer from power (step 758). If the freezer temperature is greater than the maximum for that operating mode (step 760), the freezer device controller is signaled to turn on (step 760) and reconnect the freezer to power. Instead of completely cutting power to the freezer, the freezer can be set into a lower power operating mode if such as feature is available.

Instead of checking to determine whether the temperature is greater or less than a designed minimum or maximum, more complex threshold determinations can be made as discussed separately herein. The temperature or other threshold ranges used to control power to the freezer or other critical device can vary also depending on the mode of operation for system 200 such that power savings efforts become progressively more aggressive as lower power modes of operation are entered, for example by adjusting the allowable temperature range to be more permissive of higher temperatures as the available fuel / runtime decreases. In some embodiments, more than one ERM temperature range can be specified wherein temperatures even further from ideal are permitted in very low fuel conditions. For example, a freezer that normally is set to maintain OF can be configured with a tier 1 temperature range between 5F to 15F, a tier 2 temperature range between 1 OF and 20F, an initial ERM temperature range between 15F and 3 OF, and a second ERM temperature range of between 33F and 40F that is triggered when in ERM and the remaining fuel or runtime is only a specified fraction of the ERM target.

Fig. 8 shows an embodiment in which the generator control module functionality is integrated with a transfer switch to provide an enhanced generator control transfer switch (“GCTS”) 800. Combining the transfer switch and GC module functionality advantageously may allow more refined control of the power switching. Certain transfer switch designs are configured to delay changeover to generator power until the generator power input is stable. The combined GC module / transfer switch can be configured so that the generator input can be connected or disconnected to the service panel or other downstream load independently from the transfer from utility power to generator power. When the system is operating in extreme reserve mode and the generator 115 is turned off, the connection between the generator and the load can be opened. When the system cycles the generator on again, the power output from the generator is monitored and the generator is reconnected to the load when its power input is stable. As an alternative to actively monitoring the generator, restarting the generator can trigger a timer and the generator can be reconnected to the load after a predefined period of time has elapsed.

Turning to Fig. 8, a generator control / transfer switch module 805 implements GC module and transfer switch module functionality as discussed above. Generator power 810 and utility power 815 are connected to the GCTS 800. A relay or other appropriate switch 820 can be operated by the GCTS module 805 to switch from utility to generator power if a power outage is detected and connect it to a line 830 that sends the power, e.g., to a distribution panel. Switch 820 or an additional switch 825 can be controlled to delay the connection of the generator to the panel until the generator power input has stabilized.

Line sensing circuitry 835, 840 can be provided to monitor the generator and utility power and indicate to the GCTS module 805 when utility power has been interrupted and when power from the generator has reached a steady state at an acceptable voltage and waveform. Various communication interfaces can be provided as discussed above with respect to the GC module 220, including an interface 850 to signal the generator to turn on and off, an interface 855 used to obtain fuel status information, interfaces 860 to the critical device sensor and device control modules, and network interface 865 to provide connectivity with a user or remote system server. One or more of these interfaces can be combined or separated as appropriate to the particular implementation embodiment.

The system has been discussed above in the context of a fossil fuel powered generator. However, it can also be applied to other power generator systems that can only supply a finite amount of energy under given circumstances and where conservation would be required, such as a hydrogen powered fuel cell or a solar “generator”. For a hydrogen fuel cell, the fuel supply is a measure of the hydrogen gas or other consumable used by the cell to generate electricity. A solar “generator” or solar charged battery bank can supply a limited amount of power as determined by the battery capacity. Even though solar power can be used to recharge the batteries, the charge rate may be substantially reduced during bad weather and short winter days and no charging occurs at night. The remaining charge in the battery bank, such as a number of amp-hours, can be determined using conventional battery monitoring equipment and can be treated by the system 200 in a manner similar to remaining fuel in a fuel tank 130. Stopping and starting the solar generator would entail disconnecting and reconnecting the battery bank from the power circuitry in the facility.

In various of the embodiments above, the ER mode of operation is entered when the remaining capacity of the generator is determined to be below a predefined ERM threshold. Alternative embodiments can be provided in which the system always operates in the ER mode of operation or can be selectively set to enter and remain in the ER mode of operation. In one alternative, the generator control system 200 can allow the ERM threshold to be set to a value at which the predefined ERM threshold is always met so that the system remains in the ER mode of operation. Such a system may be useful where the main purpose of the generator is to provide power to one or more critical devices. Various aspects, embodiments, and examples of the invention have been disclosed and described herein. Modifications, additions and alterations may be made by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A generator control system for use in powering a critical device and at least one other device, the generator being remotely controllable to start and stop, the critical device operative when continuously powered to maintain a value of an operating parameter within a standard control range, the system comprising: a generator control module; a first device connected to receive power from the generator; a first device control module associated with the first device and remotely controllable to selectively reduce the first device power use and to allow the first device to operate at full power; and a sensor operative to provide a measure of the value of the operating parameter; the generator control module comprising a power supply, a processor coupled to a memory having computer instructions stored therein, and being configured to receive status information from the generator and receive operating parameter value data from the sensor; the generator control module having a normal mode of operation, a first tier mode of operation, and an extreme reserve (“ER”) mode of operation, the generator control module initially being in the normal mode during which the generator is running; the computer instructions configuring the generator control module to: determine a remaining capacity of the generator based on received generator status information; enter the first tier mode when the remaining capacity drops below a first tier threshold; when in the first tier mode signaling the first control module to reduce the first device power use; enter the ER mode of operation when the remaining capacity is below a predefined ER mode (“ERM”) threshold; when in the ER mode of operation, (i) signal the generator to stop when the value of the operating parameter meets a first ERM predefined condition relative to a predefined control range, and (ii) signal the generator to start when the value of the operating parameter meets a second ERM predefined condition relative to the predefined control range.

2. The system of claim 1, wherein the remaining capacity is related to an estimated remaining runtime of the generator and the ERM threshold is a function of a predefined minimum period of time for maintaining a valid operating state of the critical device.

3. The system of claim 2, wherein the computer instructions further configure the generator control module to dynamically adjust the ERM threshold relative to the predefined minimum duration of time.

4. The system of claim 2, wherein the ERM threshold is dynamically adjusted as a function of one or more of time of day, date, ambient lighting conditions, and weather conditions.

5. The system of claim 1, wherein remaining capacity is determined based on at least one of one of a measured amount of remaining fuel and an estimated amount of remaining fuel, and wherein the ERM threshold is one or more of an amount of remaining fuel, and a percentage of remaining fuel.

6. The system of claim 1, wherein remaining capacity is determined based on a power consumption profile of the generator and load on the generator during the ER mode of operation.

7. The system of claim 1 , wherein the sensor comprises a plurality of sensors and the value of the operating parameter is a function of data received from the plurality of sensors.

8. The system of claim 6, the computer instructions further configuring the generator control module to monitor power drawn from the generator and fuel consumption of the generator over time to determine the power consumption profile for the generator.

9. The system of claim 6, the generator control module connectable to a network, the computer instructions further configuring the generator control module to access a remote location over the network and retrieve the power consumption profile from the remote location.

10. The system of claim 1 , further comprising a user interface through which data can be output to a user and received from a user, the computer instructions further configuring the generator control module to: output through the user interface the predefined ERM threshold and the predefined control range; and receive as input through the user interface values for the predefined ERM threshold and the predefined control range.

11. The system of claim 10, wherein the user interface comprises a display coupled to the generator control module.

12. The system of claim 10, wherein the user interface is accessible by a remote computing device through one of a website and an API.

13. The system of claim 1, wherein the predefined control range is independent of the standard control range.

14. The system of claim 1 , wherein the operating parameter is a temperature and the predefined control range comprises a minimum operating temperature and a maximum operating temperature.

15. The system of claim 14, wherein the first predefined ERM condition is met when the value of the operating parameter is less than the minimum temperature, and the second predefined ERM condition is met when the value of the operating parameter is greater than the maximum operating temperature.

16. The system of claim 14, wherein the second predefined ERM condition is met when the value of the operating parameter is greater than the maximum operating temperature for a predefined period of time.

17. The system of claim 16, wherein the predefined period of time is a function of a difference between the maximum operating temperature and the value of the operating parameter.

18. The system of claim 14, wherein the critical device is a refrigeration device and the value of the operating parameter is a measure of temperature within the refrigeration device.

19. The system of claim 18, wherein the refrigeration device comprises a freezer and the value of the operating parameter is a measure of temperature within the freezer.

20. The system of claim 18 further comprising: a sensor module comprising the sensor; the sensor module in data communication with the generator control module using one of a wired and a wireless data connection, the sensor module configured to provide the measure of the value of the operating parameter to the generator control module.

21. The system of claim 20, wherein the sensor module transmits data to the generator control module on a periodic basis.

22. The system of claim 20, wherein the generator control module is configured to periodically poll the sensor module to read data from the sensor.

23. The system of claim 20, wherein the sensor module is configured to transmit data to the generator control module in response to a determination within the sensor module that the value of the operating parameter meets a predefined transmission condition.

24. The system of claim 23, wherein the predefined transmission condition is met when either the value of the operating parameter meets the first predefined ERM condition or the value of the operating parameter meets the second predefined ERM condition.

25. The system of claim 23, wherein the sensor is a temperature sensor, the sensor module is configured to send data to the generator control module in response to at least one of the sensed temperature being greater than a maximum predefined temperature and the sensed temperature being less than a minimum predefined temperature.

26. The system of claim 20, wherein the sensor module is integrated with the refrigeration device and sensor readings are provided through a wireless communication protocol.

27. The system of claim 14, wherein the critical device is one of an air conditioner or a heater and the value of the operating parameter is a measure of air temperature in at least one location.

28. The system of claim 27, wherein the sensor is integrated within a thermostat connected to the critical device.

29. The system of claim 1, the computer instructions further configuring the generator control module to enter the ER mode of operation in response to receipt of a manual ERM initiation signal.

30. The system of claim 1, the computer instructions further configuring the generator control module to: when in the ER mode of operation, enter an ER override mode of operation in response to an ERM override condition and, if the generator is off, send a start signal to the generator wherein the generator remains on during the ER override mode of operation; and return to the ER mode of operation in response to an end of the ERM override condition.

31. The system of claim 30, the computer instructions further configuring the generator control module to disable the ER override mode of operation when the remaining capacity is below a predefined override cutoff threshold.

32. The system of claim 30, further comprising an override circuit to send an override signal to the generator control module, the ERM override condition triggered by receipt by the generator control module of the override signal.

33. The system of claim 32, the override circuit contained within a housing; the override circuit further comprising a wireless communication system connectable to the generator control module over which the override signal can be sent.

34. The system of claim 33, the override circuit comprising a physical switch that can be activated by a user to initiate the ERM override condition.

35 The system of claim 34, wherein the housing of the override circuit has a form factor allowing it to be hand-held.

36. The system of claim 33, wherein the override circuit is associated with the first device.

37. The system of claim 33, the first device responsive to signals from a device remote control, the override circuit comprising a wireless signal detector responsive to signals from the device remote control, the override circuit configured to detect a specified signal from the device remote control and in response send the override signal to the generator control module.

38. The system of claim 37, wherein the specified signal is a power on signal for the first device.

39. The system of claim 37, the override circuit further comprising a wireless emitter, the override circuit configured, in response to a signal indicating that full power to the first device has been restored, to output on the wireless emitter the power on signal for the first device.

40. The system of claim 33, the computer instructions further configuring the generator control module to signal the first device control module to allow the first device to operate at full power when the ER override mode of operation is entered in response to an ERM override condition being triggered by the override switch.

41. The system of claim 32, wherein the generator control module is configured to exit the ERM override condition a predefined override time period after activation of the ER override mode.

42. The system of claim 30, further comprising an override sensor connectable to the first device, the ERM override condition comprising a detection by the override sensor of an attempt to use the first device.

43. The system of claim 42, the override sensor detecting the attempt to use the first device by detection of at least at least one of a change in load, resistance, inductance, and impedance on a power supply line of the first device.

44. The system of claim 43, wherein the override sensor is contained in a housing configured to clamp onto the power supply line of the first device.

45. The system of claim 42, wherein the override sensor is part of the first device control module, the override sensor operative to detect an attempt to use the first device while the first control module is set to reduce the first device power use.

46. The system of claim 45, the override sensor module configured to detect an attempt to use the first device when the first device is isolated from a power supply.

47. The system of claim 32, the override switch comprising a water level detection sensor.

48. The system of claim 47, the water level detection sensor being in a housing configured to mount within a tank of a flush toilet; wherein the water level detection sensor will detect when the toilet is flushed and wherein a water pump and/or sump pump can be connected to the circuit to receive power when the generator is in the ER override mode of operation and a toilet flush is detected.

49. The system of claim 1 , wherein the first device control module is in communication with the generator control module through one of a direct wired connection, a wireless connection, and a powerline data transmission system.

50. The system of claim 1, wherein the first device is connected to power through the first device control module, and the first device control module selectively reduces the first device power use by disconnecting the first device from power.

51. The system of claim 1, wherein the first device is connected to power through the first device control module, and the first device control module selectively reduce the first device power use by limiting the amount power provided to the first device through the first control module.

52. The system of claim 1, the first device control module configured to be connectable to a first power outlet and having a second power outlet to which the first device can be connected to receive power, the device control module configured to reduce the first device power use by one of stopping power from being supplied to the second power outlet, limiting the power supplied to the second power outlet to a maximum amperage, and reducing a voltage at the second power outlet relative to a voltage at the first power outlet.

53. The system of claim 1, wherein the first device control module is integrated with the first device.

54. The system of claim 1, wherein the first device is a lighting device and the first device control module is configured to reduce power draw from the lighting device by lowering an intensity of light provided by the lighting device.

55. The system of claim 1, the computer instructions further configuring the generator control module to send an alert signal to the first device control module prior to signaling the first device control module to reduce the first device power use; the device control module configured to output a user alert in response to receipt of the alert signal.

56. The system of claim 55, wherein the user alert is a human perceivable audio and/or visual signal.

57. The system of claim 55, wherein the user alert is message sent over a communication network to a designated user.

58. The system of claiml, the first device control module is configured to output a user alert in response to the signal from the generator control module to reduce the first device power use, wherein the device control module operates to reduce the first device power use a predefined period of time after output of the alert signal.

59. The system of claim 58, wherein the user alert is a human perceivable audio and/or visual signal.

60. The system of claim 58, wherein the user alert is message sent over a communication network to a designated user.

61. The system of claim 1, the first device control module configured to issue a shutdown signal to the first device in response to the signal from the generator control module to reduce the first device power use.

62. The system of claim 1, further comprising: a plurality of device control modules, each device control module associated with a respective device and remotely controllable to selectively reduce the respective device power use and to allow the respective device to operate at full power; the generator control module further having a plurality of tier modes of operation, each tier mode of operation having a respective tier threshold; each of the plurality of device control modules assigned to a respective tier threshold; the computer instructions further configuring the generator control module to, in response to detection of the remaining capacity going below the tier threshold for a particular tier mode, signal each respective device control module associated with the particular tier mode to reduce the power use by the respective devices connected to the respective device control modules.

63. The system of claim 62, the computer instructions further configuring the generator control module to signal the respective device control modules by broadcasting a tier entry message to the plurality of device control modules indicating a particular tier mode that has been entered; a respective device control module comprising a mode selection switch to assign the respective device control module to a specific tier, the respective device control module responsive to receipt of a tier entry message for the assigned specific tier.

64. The system of claim 62, each device control module having a unique device ID; the memory having a device tier table stored therein associating each device control module with at least one tier; the computer instructions configuring the generator control module to signal the device control modules associated with the particular tier by sending a respective message to each of the plurality of device control module IDs associated with the particular tier as indicated by the device tier table.

65. The system of claim 62, further comprising a user interface through which data can be output to a user and received from a user, the computer instructions further configuring the generator control module to: indicate the device control modules assigned to each defined tier ; receive input to assign a device control module to a selected tier; indicate for each tier mode the corresponding tier threshold; and receive input to set a tier threshold for a selected tier.

66. The system of claim 1, the generator control module connected to the generator through a wired or wireless generator interface, the generator control module sending the stop and start signals to the generator over the generator interface.

67. The system of claim 1 , further comprising a transfer switch connectable to the generator and a primary power supply; the transfer switch operative to automatically start the generator upon detection by the transfer switch of a loss of power on the primary power supply; the generator control module connected to the transfer switch, wherein the generator control module sends the stop signal and start signal to the generator through the transfer switch.

68. The system of claim 67, wherein the generator control module is integrated with the transfer switch.

69. The system of claim 1 , the system comprising a plurality of circuits connected to a service panel through which power from the generator can be distributed to the plurality of circuits, the first device connected to a first circuit, the first device control module controlling power use by components on the first circuit.

70. The system of claim 1, the generator further having a startup battery that is charged when the generator is running and that has a minimum charge deemed insufficient to start the generator; the computer instructions configuring the generator control module to signal the generator to stop when in the ER mode of operation further comprise instructions to defer signaling the generator to stop if a charge status of the startup battery is less than the minimum charge.

71. The system of claim 70, the computer instructions further configuring the generator control module to: disconnect the generator from powered devices when the value of the operating parameter meets the first ERM predefined condition relative to the predefined control range and the charge status of the battery is below the minimum charge; and if the generator is disconnected, reconnect the generator after the charge status of the battery returns to at least the minimum charge.

72. A system for controlling a generator providing power to a refrigeration device and at least one additional device, the generator having a fuel supply and being remotely controllable to start and stop, the refrigeration device when powered operative to maintain a temperature of a chamber in the refrigeration device below a predefined maximum temperature; the system comprising: a generator control module; at least one device control module, each device control module remotely controllable to selectively reduce the power use by a respective additional device associated with the respective device control module and to allow the respective additional device to operate at full power; and a sensor module comprising a temperature sensor providing a measure of the temperature in the chamber, the sensor module in data communication with the generator control module; the generator control module comprising a power supply, a processor coupled to a memory having computer instructions stored therein, and being configured to receive status information from the generator and receive temperature data from the temperature sensing module; the generator control module having a normal mode of operation, at least one tier mode of operation, and an extreme reserve (“ER”) mode of operation, each device control module associated with a respective tier; the computer instructions configuring the generator control module to: determine a remaining capacity of the generator based on received generator status information; and enter a respective tier mode of operation when the remaining capacity drops below a respective tier threshold; when in a respective tier mode of operation signaling the device control modules associated with the respective tier to reduce power use by the respective additional devices associated with the signaled device control modules; enter the ER mode of operation when the remaining capacity is below a predefined ER mode (“ERM”) threshold;

(ii) when in the ER mode of operation: monitor temperature data from the sensor module; send a stop signal to the generator when the temperature of the chamber is below a predefined ERM minimum temperature; and send a start signal to the generator when the temperature of the chamber is greater than a predefined ERM maximum temperature.

73. The system of claim 72, wherein the remaining capacity is related to an estimated remaining runtime of the generator and the ERM threshold is a function of a predefined minimum period of time for maintaining the temperature in the chamber below a predefined maximum.

74. The system of claim 73, wherein the computer instructions further configure the generator control module to dynamically adjust the ERM threshold relative to the predefined minimum duration of time.

75. The system of claim 73, wherein the ERM threshold is dynamically adjusted as a function of one or more of time of day, date, ambient lighting conditions, and weather conditions.

76. The system of claim 72, wherein the sensor module is configured to signal the refrigeration device to disable one or more refrigeration device sub-systems in response to a signal from the generator control module that the ER mode of operation has been entered.

77. The system of claim 74, wherein the sub-systems comprise at least one of an ice maker and an anti-frost system.

78. The system of claim 72, wherein the sensor module is integrated with the refrigeration device.

79. The system of claim 72, the sensor module comprising a first portion positioned outside of the refrigeration device and a second portion positioned inside of the chamber, wherein the temperature sensor is in the second portion.

80. The system of claim 72, further comprising a refrigerator control module configured to selectively reduce power use by the refrigeration device and allow the refrigeration device to operate at full power; the sensor module in data communication with the generator control module through the refrigerator control module.

81. A transfer switching system to selectively connect a primary power supply and a generator to a load circuit and for controlling the generator to power a critical device on the load circuit, the system comprising: a primary power input connectable to the primary power supply; a backup power input connectable to the generator; a power output connectable to the load; a power switch having a switch output selectively connectable to the primary power input and the backup power input; a generator interface connectable to the generator and over which signals can be sent to the generator to start the generator and stop the generator; a generator fuel status input; a critical device interface; and a control module; the control module having a normal operating mode, a backup operating mode, and an extreme reserve (“ER”) mode of operation, the control module operative to:

(i) in the normal operating mode: connect the power switch to the primary power input; and enter the backup operating mode when detecting a loss of power on the primary power input;

(ii) in the backup operating mode: send a start signal to the generator; determine a remaining capacity of the generator based fuel status; and enter the extreme reserve (“ER”) mode of operation when the remaining capacity is below a predefined ER mode (“ERM”) threshold; wherein the generator remains on during the backup mode;

(iii) when in the ER mode of operation: monitor the value of an operating parameter of the critical device over the critical device interface; send a stop signal to the generator when the value of the operating parameter meets a first ERM predefined condition relative to a predefined control range; and send a start signal to the generator when the value of the operating parameter meets a second ERM predefined condition relative to the predefined control range.

82. The system of claim 81, wherein the ERM threshold is one or more of an amount of remaining fuel for the generator, a percentage of remaining fuel for the generator, and a calculated remaining capacity of the generator.

83. The system of claim 82, wherein the remaining capacity is related to an estimated remaining runtime of the generator and the ERM threshold is a function of a predefined minimum period of time for maintaining a valid operating state of the critical device.

84. The system of claim 82, wherein the computer instructions further configure the generator control module to dynamically adjust the ERM threshold relative to the predefined minimum duration of time.

85. The system of claim 82, wherein the ERM threshold is dynamically adjusted as a function of one or more of time of day, date, ambient lighting conditions, and weather conditions.

86. The system of claim 79, further comprising a user interface, the system operative to: output through the user interface the predefined ERM threshold and the predefined control range; and receive as input through the user interface values for the predefined ERM threshold and the predefined control range.

87. The system of claim 86, wherein the user interface is accessible by a remote computing device through one of a website and an API.

88. The system of claim 86, wherein the operating parameter is a temperature and the predefined control range comprises a minimum temperature and a maximum temperature.

89. A system for controlling a generator electrically connected to first and second critical devices through a circuit, the generator having a fuel supply and being remotely controllable to start and stop, each critical device when powered operative to maintain a respective value of a respective operating parameter within a respective predefined standard range, wherein the value of the operating parameter can drift outside the predefined standard range when the respective critical device is unpowered, the system comprising: a generator control module; a first sensor to provide a measure of the value of the first operating parameter to the generator control module; a second sensor to provide a measure of the value of the second operating parameter to the generator control module; a first device control module associated with the first critical device and remotely controllable to selectively reduce the first critical device power use while power is available and to allow the first critical device to operate at full power; a second device control module associated with the second critical device and remotely controllable to selectively reduce the first critical power use while power is available and to allow the second critical device to operate at full power; and a third device control module associated with a non-critical device and remotely controllable to selectively reduce the non-critical device power use while power is available and to allow the non-critical device to operate at full power; the generator control module comprising a power supply, a processor coupled to a memory having computer instructions stored therein, and being configured to receive status information from the generator and receive operating parameter value data from the sensors; the generator control module having a normal mode of operation, a first tier mode of operation, and an extreme reserve (“ER”) mode of operation, the generator control module initially being in the normal mode during which the generator is running; the computer instructions configuring the generator control module to: determine a remaining capacity of the generator based on received generator status information; enter the first tier mode when the remaining capacity drops below a first tier threshold; when in the first tier mode signaling the third control module to reduce the non- critical device power use; enter the extreme reserve (“ER”) mode of operation when the remaining capacity is below a predefined ER mode (“ERM”) threshold; when in the ER mode of operation: monitor the value of the first operating parameter and the value of the second operating parameter; determine if the value of the first operating parameter meets a first power on condition and determine if the value of the first operating parameter meets a first power off condition; determine if the value of the second operating parameter meets a second power on condition and determine if the value of the first operating parameter meets a second power off condition; send a stop signal to the generator when the generator is on and both the first power off condition and the second power off condition are met; send a start signal to the generator when at least one of the first power on condition and second power on condition is met.

90. The system of claim 89, wherein the remaining capacity is related to an estimated remaining runtime of the generator and the ERM threshold is a function of a predefined minimum period of time for maintaining a valid operating state of the critical device.

91. The system of claim 90, wherein the computer instructions further configure the generator control module to dynamically adjust the ERM threshold relative to the predefined minimum duration of time.

92. The system of claim 90, wherein the ERM threshold is dynamically adjusted as a function of one or more of time of day, date, ambient lighting conditions, and weather conditions.

93. The system of claim 90, the computer instructions configuring the generator control module to: signal the first device control module to reduce the first critical device power use when the value of the first operating parameter meets the first power off condition; signal the first device control module to allow the first critical device to operate at full power when the value of the first operating parameter meets the first power on condition; signal the second device control module to reduce the second critical device power use when the value of the second operating parameter meets the second power off condition; and signal the second device control module to allow the second critical device to operate at full power when the value of the second operating parameter meets the second power on condition.

94. The system of claim 91, wherein each respective control module operates to reduce power use by a respective controlled device by disconnecting the respective controlled device from generator power.