WO2014005616A1

WO2014005616A1 - Energy scheduling to a load in building automation system

Info

Publication number: WO2014005616A1
Application number: PCT/EP2012/062834
Authority: WO
Inventors: Ewa Hansen; Tomas Lennvall; Larisa RIZVANOVIC; Judith Rossebø; Pia Stoll
Original assignee: ABB Research Ltd Switzerland
Current assignee: ABB Research Ltd Switzerland
Priority date: 2012-07-02
Filing date: 2012-07-02
Publication date: 2014-01-09
Anticipated expiration: 2015-01-02

Description

ENERGY SCHEDULING TO A LOAD IN BUILDING AUTOMATION SYSTEM

TECHNICAL FIELD

The present disclosure generally relates to building automation systems and in particular to a method, a computer program, and an energy management unit for determining a schedule for energy delivery to at least one load in a building automation system.

BACKGROUND

According to the European Council (European Commission Research), the energy consumption of houses and buildings, taking into account the whole life cycle, corresponds to 40% of total EU energy consumption. Both transportation and food production consume less energy than our buildings.

Energy consumption of the residential building sector and the commercial building sector thus forms a non-negligible portion of all sectors' energy consumption. To that end, the energy costs of and the environmental impact provided by buildings are substantial. For the purpose of reducing energy costs, demand response programs for large-scale consumers such as industrial plants or commercial buildings are today in existence. The possibilities for an end-user of a building automation system to change settings/parameters of the building automation system are, particularly in contrast to the possibilities of building technicians and building engineers, limited to set preferences and actions, like setting thermostats or setting up a weekly scheme for blinds, based on information from sensors connected to the building automation system.

The publication "Wireless Sensor Networks for Cost-Efficient Residential Energy Management in the Smart Grid" by Erol-Kantarci et al., published in IEEE Transactions on smart grid, vol. 2, no. 2, June 2011, evaluates the performance of an in-home energy management system (iHEM) application. The performance of iHEM is compared with an optimization-based

residential energy management scheme whose object is to minimize the energy expenses of the consumers by scheduling appliances to less expensive hours according to time-of-use tariffs. The possibility to control energy costs and the environmental impact of energy consumption is however still limited.

There is hence a need to improve existing solutions for end-user control of building automation systems.

SUMMARY

In view of the above, a general object of the present disclosure is to provide a method, a computer program and an energy management unit for energy delivery to at least one load in a building automation system.

The ideas presented in the disclosure are based on the understanding that in order to reduce electricity consumption, visualization and control of the electricity consumption for individual outlets could advantageously be provided.

Hence, according to a first aspect of the present disclosure there is provided a method of determining a schedule for energy delivery to at least one load in a building automation system. The method comprises: acquiring an

association between at least two parameters and a schedule for delivery of energy to at least one load in accordance with acquired energy need for the at least one load, each one of the at least two parameters relating to priority of a respective property associated with the delivery of energy. The method further comprises receiving end-user selection data relating to weighting of the at least two parameters for the at least one load. The method further comprises determining the schedule for the energy delivery to the at least one load based on the weighting of the at least two parameters.

Advantageously this enables the energy delivery to the at least one load based on end-users' preference A first parameter of the at least two parameters may relate to carbon dioxide emission statistics associated with the energy to be delivered to the at least one load. A second parameter of the at least two parameters may relate to a cost per time unit of the energy to be delivered to the at least one load, the cost being payable by an end-user of the building automation system.

Advantageously this enables the end-user to optimize between emission and cost.

The energy delivery may comprise delivery of a first kind of energy, the first kind of energy being associated with high priority of the first parameter and low priority of the second parameter. The energy delivery may comprise delivery of a second kind of energy, the second kind of energy being associated with high priority of the second parameter and low priority of the first parameter. Amounts of the first kind of energy and the second kind of energy may be delivered in accordance with the weighting. Advantageously this enables the end-user to optimize between different kinds of energy to be delivered.

The building automation system is preferably a building automation system for use in a residential home or in an office building, a shopping mall, a factory, etc. According to a second aspect of the present disclosure there is provided a computer program for determining a schedule for energy delivery to at least one load in a building automation system, the computer program comprising computer program code which, when run on a energy management unit, causes the energy management unit to perform a method according to the first aspect

According to a third aspect of the present disclosure there is provided a computer program product comprising a computer program according to the second aspect and a computer readable means on which the computer program is stored. According to a fourth aspect of the present disclosure there is provided an energy management unit for determining a schedule for energy delivery to at least one load in a building automation system, comprising a processing unit arranged to acquire an association between at least two parameters and a schedule for delivery of energy to at least one load in accordance with acquired energy need for the at least one load, each one of the at least two parameters relating to priority of a respective property associated with the delivery of energy; an input unit arranged to receive end-user selection data relating to weighting of the at least two parameters for the at least one load; and the processing unit further being arranged to determine the schedule for the energy delivery to the at least one load based on the weighting of the at least two parameters.

It is to be noted that any feature of the first, second, third and fourth aspects may be applied to any other aspect, wherever appropriate. Likewise, any advantage of the first aspect may equally apply to the second, third, and/or fourth aspect, respectively, and vice versa. Other objectives, features and advantages of the enclosed embodiments will be apparent from the following detailed disclosure, from the attached dependent claims as well as from the drawings. Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a/an/the element, apparatus, component, means, etc. are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, etc., unless explicitly stated otherwise. Moreover, any step in a method need not necessarily have to be carried out in the presented order, unless explicitly stated otherwise.

BRIEF DESCRIPTION OF THE DRAWINGS

The specific embodiments of the inventive concept will now be described, by way of example, with reference to the accompanying drawings, in which: Fig. l is a schematic diagram of an energy management unit; Fig. 2 depicts a building automation system including the energy

management unit in Fig. l;

Figs. 3a-d are schematic view of displays of a user interface for determining a schedule for energy delivery by means of the energy management unit in Fig. l; and

Fig. 4 is a flowchart of a method for scheduling the operation of a load in a building automation system.

DETAILED DESCRIPTION

The inventive concept will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplifying

embodiments are shown. The inventive concept may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided by way of example so that this disclosure will be thorough and complete, and will fully convey the scope of the inventive concept to those skilled in the art. Like numbers refer to like elements throughout.

Home automation energy management strategies as herein defined and as executed by the herein defined an energy management unit may operate using different principles. The energy management strategies could for instance optimize energy consumption based on low price, or C0₂ emissions for producing the energy which is delivered to a load in the building automation system.

Energy with low emission (so-called "green energy") is generally more expensive than energy with high emission. Furthermore, it may be desirable by the end-user to be informed of, or even be able to control, the production location of the energy being delivered. For example, the end-user may prefer locally produced energy over remotely produced energy. As the skilled person understands, emission, cost, and location are just three parameters of the energy delivered that the end-user may wish to control. The relation between price, location and C0₂ is generally considered to be complicated and thus optimizing for C0₂ might not result in a low cost or locally produced energy and vice versa. Therefore, the determined energy management strategy directly influences the cost or environmental impact preference for the end- user. Thus, it is desirable that the end-user is informed on what basis the current energy management strategy is based on, or even that the end-user, by means of providing end-user selection data through a user interface can control or at least influence the strategy used. The desired strategy can vary from time to time and thus end-user control of the strategy may be beneficial or in some situations even required.

The disclosed embodiments enable the end-user not only to become aware of but also control the basic principles of the energy management strategy through interaction with a user interface. The user interface preferably provides a simple and intuitive way to select which parameters and how much each parameter should influence the strategy. Particularly, the disclosed energy management unit enables a weighting between cost and emission. The disclosed embodiments thus enable an end-user to select how much different parameters influence the energy management strategy for the building through interaction with a user interface, instead of the end-user being restricted to a building automation system that only has a pre-set end- user strategy.

Fig. l is an example of an energy management unit l for use in a building automation system for load scheduling/control. A building in this context may be a commercial building such as an office building, a sports arena, an airport, or a factory. Building may alternatively refer to a residential home, wherein the building automation system is a home automation system.

Examples of building automation systems for the purpose of this disclosure are the Building Automation and Control System (BACS) and the Home and Building Electronic System (HBES).

As defined herein a load relates to a heating functionality, a lighting functionality, and/or electricity consumption of the building automation system. Particularly the load may take the form of an electricity consuming entity that may be connected to the energy management unit l, e.g. for scheduling and controlling of how and when the load should be operated. A load may for example be a lighting system, a heating, ventilation and air conditioning (HVAC) unit, a thermostat or home appliances such as a washing machine, a tumble dryer, or a dishwasher.

Returning now to Fig. l, the energy management unit l comprises an input unit 3, an output unit 5 and a processing unit 4 operatively connected to the input unit 3 and the output unit 5.

The energy management unit 1 may act as a network node between a first communications network that is external to the building automation system in which the energy management unit 1 may be arranged, and a second communications network which is internal to the building(s) with which the energy management unit 1 is associated. The energy management unit 1 may hence be seen as a gateway acting as an interface between the first communications network and the second communications network.

The energy management unit 1 may be configured by means of a user interface UI, as schematically illustrated in Fig. 2. The user interface UI may be integrated with the energy management unit 1, or the user interface UI may be separate from the energy management unit 1. The user interface UI may for example be provided in the form of an application in a smart phone, a tablet computer, or it may be accessible through a web browser.

The input unit 3 of the energy management unit 1 is arranged to receive data determined and/or generated by other devices, units and entities operatively connected to the input unit 3 and to provide the processing unit 4 with the received data.

The output unit 5 of the energy management unit 1 is arranged to provide other devices, units and entities operatively connected thereto with data determined and/or generated by the processing unit 4. The processing unit 4 is arranged to receive input data from the input unit 3, generate output data based on the input data and provide the output unit 5 with the output data.

Fig. 2 shows a building automation system 9 comprising an energy management unit 1, a user interface UI arranged to be in communication with the energy management unit 1, and a plurality of loads L arranged to be in communication with the energy management unit 1. The energy

management unit 1 is arranged to communicate with e.g. a service provider SP via a first communications network Ni. The energy management unit 1, the user interface UI and the plurality of loads L form part of a second communications network N2 that is internal to the building automation system 9 in the sense that it is a local network. Each of the first

communications network Ni and the second communications network N2 may be a wireless network or a wired network. Hence, the energy

management unit 1 may be arranged to communicate wirelessly, by means of wires, or a combination of wireless and wired communication. Examples of suitable wired communications standards are IEEE P1901, ITU-T G.Hn, ANSI/CEA 709.2, and KNX (a standardized (EN 50090, ISO/IEC 14543), OSI-based network communications protocol for intelligent buildings), and examples of suitable wireless communications standards are Zigbee, Wi-Fi, and Z-wave.

The operation of the energy management unit 1, including performing a method of determining a schedule for energy delivery to at least one load in a building automation system, will now be described in more detail with reference to the energy management unit of Fig 1, the building automation system of Fig 2, the user interfaces of Figs. 3a-d and the flowchart of Fig. 4.

Typically, upon installation of the energy management unit 1 in a building automation system 9, the energy management unit 1 acquires, in a step Si, an association between at least two parameters and a schedule for delivery of energy. The delivery of energy relates to delivery of energy to at least one load in accordance with acquired energy need for the at least one load. According to embodiments the delivery of energy may comprise delivering zero energy to at least one of the at least one loads. Each one of the at least two

parameters relates to priority of a respective property associated with the delivery of energy to the at least one load. A first parameter of the at least two parameters may relate to carbon dioxide emission statistics associated with the energy to be delivered to the at least one load. A second parameter of the at least two parameters may relate to a cost per time unit of the energy to be delivered to the at least one load. As herein defined the cost is preferably defined as the cost for the energy consumed by the building automation system being payable by the end-user of the building automation system. A third parameter of the at least two parameters may relate to location of production of the energy to be delivered to the at least one load.

The carbon dioxide emission levels may be generated based on carbon dioxide emission statistics that may be stored in the energy management unit. The carbon dioxide emission statistics can be stored in the energy management unit l e.g. during manufacturing, or it may be received by the energy management unit l via for example the first communications network Ni upon installation in a building automation system. Carbon dioxide emission statistics (for at least a pre-determined time period) may for example be received from a service provider, e.g. a retailer or the utility, prior to determining the schedule. Alternatively, the carbon dioxide emission statistics may be stored in the energy management unit l based on for example country specific statistics concerning carbon dioxide emission. To this end, the carbon dioxide emission data may be dynamic if delivered by a service provider or static in case country specific statistics are utilised. Thus, the energy management unit l may be arranged to receive, in a step S2, carbon dioxide emission statistics from a service provider SP of the energy to be delivered. The statistics may comprise historical data of as well as predictions for future carbon dioxide emission. According to embodiments the statistics are received prior to acquiring the association between the at least two parameters and the schedule. The first parameter may thereby be associated with a carbon dioxide emission level (Ci, C2, C3, C4). The energy management unit l may further be provided with energy cost level data comprising a plurality of energy cost levels. The energy cost levels may be generated based on energy cost statistics that may be stored in the energy management unit l. The energy cost statistics can be stored in the energy management unit l e.g. during manufacturing, or may be received by the energy management unit l via for example the first communications network Ni upon installation in the building automation system l. The energy cost statistics (for at least a pre-determined time period) may for example be received from a service provider, e.g. a retailer or the utility, prior to determining the schedule. Alternatively, the energy cost statistics may be stored in the energy management unit l based on for example country specific statistics concerning energy costs. To this end, the energy cost statistics may be dynamic if delivered by a service provider or static in case country specific statistics are utilised. Thus, the energy management unit l may be arranged to receive, in a step S3, cost per time unit statistics from a service provider SP of the energy to be delivered. The statistics may comprise historical data of as well as predictions for future cost per time unit. The second parameter may thereby be associated with an end-user cost level (Li, L2, L3, L4). According to embodiments the carbon dioxide emission statistics and the energy cost statistics are received prior to acquiring the association between the at least two parameters and the schedule. The input unit 3 may thus be arranged to receive data representing carbon dioxide emission statistics and energy cost statistics from one or more service providers. In a step S7a, a current energy consumption level of the load may be provided to the user interface.

The at least two parameters are preferably provided to a user interface UI. Fig. 3a shows an example of user interface graphics 11a presented to an end- user by means of the user interface UI. Although the example is provided in a home automation context, it is to be noted that similar principles also apply for commercial building automation. The user interface graphics 11a comprises icons I1-I4 of home appliances, i.e. loads, such as a washing machine in icon Ii, a charger for an electric vehicle in icon I2, a lighting system in icon I3 and HVAC in icon I4. The end-user may select any of the icons presented in the user interface graphics 11a and relate the icon to the at least two parameters associated with a schedule for delivery of energy to a load represented by the icon. The end-user is the able to, via the user input determine a priority between the at least two parameters. The input unit 3 is therefore arranged to, via a user interface UI, receive end-user selection data concerning priority between the at least two parameters.

Figs 3b and 3c illustrate user interfaces by means of which and end-user could select a preferred strategy for energy management. Fig. 3b illustrates user interface graphics lib arranged to receiver user input relating to priority of cost in relation to carbon dioxide emission of the energy to be delivered to the selected load. In Fig. 3b user input may be received from user actuation of the slider bar 7. The slider bar 7 may thus be used by the end-user to select how much of cost and carbon dioxide emission should be weighted as basis for the energy management. Similarly, in Fig 3c, which illustrates user interface graphics 11c, the end-user is able to prioritize between three parameters; cost, carbon dioxide emission and production location of the energy to be delivered to the selected load. In Fig. 3c user input may be received from user actuation of a movable cursor 9. As the skilled person understands the user interface graphics 11b, 11c are just two examples of how user input relating to the at least two parameters may be received. For example, instead of being provided as a slider bar the user interface may be provided with a rotatable button. Further, as the skilled person understands the user interface graphics 11b, 11c are easily extendable to more than three parameters. Common to both the user interface graphics 11b and the user interface graphics 11c is that there is provided one single end-user control (a slider bar 7 or a movable cursor 9) for receiving both the first and the second parameter. The one single end-user control thus enables weighting of the at least two parameters. The user interface UI is thus further arranged to allow an end-user to configure a constraint concerning a level of importance between the different parameters. Data concerning the weighting of the at least two parameters for the at least one load is provided to the energy management unit l in the form of end-user selection data. Thus, the energy management unit 1 is arranged to receive, in a step S4, end-user selection data relating to weighting of the at least two parameters for the at least one load. The user interface provides a simple and intuitive way of setting and changing end-user preferences.

The energy management unit 1 is then arranged to in a step S5 determine the schedule for the energy delivery to the at least one load based on the weighting of the at least two parameters. The processing unit 4 is therefore arranged to process end-user selection data. In embodiments where at least one of carbon dioxide emission data and energy cost data is received from a service provider, the processing unit 4 is also arranged to process such data. Based on the values of the at least two parameters determined by the weighting determined from end-user input the processing unit 4 is arranged to determine the schedule for the energy delivery to the at least one load that provides optimal operation of the loads.

The determining is generally based on an optimisation of a scheduling function based on the at least two parameters associated with the at least one load. The energy management unit 1 is preferably arranged to, once the schedule for the energy delivery has been determined, deliver, in a step S6 energy to the at least one load according to the determined schedule. In a step Syb, a current energy consumption level of the load may be provided to the user interface.

The user interface may further be arranged to display the effect of the one single end-user control regarding the preferred strategy for energy

management (e.g. between price and carbon dioxide emission). Thereby the amount of carbon dioxide emission to be emitted can be determined based on the determined configuration. This determination may also be based on what kind of loads that are to be provided with the delivered energy. Hence also an indication of what loads that will be run under a certain price per carbon dioxide emission level may be determined and provided to the user interface. Since carbon dioxide emission statistics and cost per time unit statistics may be provided, a forecast (say, for the next 24 hours or so) for future price per carbon dioxide emission level may be determined. The current energy consumption level may thus further comprise a forecast for a future energy consumption level based on the current end-user selection data. Thereby the effect of the currently determined configuration (as based on the current end- user selection data) may be simulated. The values may be re-calculated if further end-user control input is received. Furthermore, a number of scenarios for different weightings of the first parameter and the second parameter could be pre-calculated in order to facilitate for the end-user how to determine the end-user control input.

Depending on the determined schedule there may be different kinds of energy delivered. For example, each one of the at least two parameters may be associated with one kind of preferred kind of energy. For example, the energy delivery may comprises delivery of a first kind of energy, where the first kind of energy is associated with high priority of the first parameter and optionally also a low priority of the second parameter. Likewise, the energy delivery may comprise delivery of a second kind of energy, wherein the second kind of energy is associated with high priority of the second

parameter and optionally also low priority of the first parameter. In case the first of the at least two parameters correspond to prioritizing a low level of carbon dioxide emission one example of the first kind of energy may be energy produced by wind power or water power. In case the second of the at least two parameters correspond to prioritizing a low cost for the end-user one example of the second kind of energy may be energy produced by a nuclear power plant or from coal. Amounts of the first kind of energy and the second kind of energy may be delivered in accordance with the weighting.

The determined schedule for the energy delivery may be related to any of the carbon dioxide emission levels C1-C4. Similarly, the determined schedule for the energy delivery may be related to any of the end-user cost levels (Li, L2, L3, L4). This is illustrated by the user interface graphics lid of Fig. 3d. The output unit 5 may thus be arranged, based on carbon dioxide emission statistics stored in the energy management unit l, to provide carbon dioxide emission control parameters to the user interface UI. Likewise, the output unit 5 may thus be arranged, based on energy cost statistics stored in the energy management unit l, to provide energy cost level data of a plurality of energy cost levels to the user interface UI. The end-user is thereby provided with information regarding which carbon dioxide emission level and energy cost level the determined schedule for the energy delivery to the load corresponds to.

The carbon dioxide emission levels may for example be displayed according to the amount of emission, e.g. the highest emission level Ci on top, with the lower levels C2-C4 being presented in decreasing order. Similarly the end- user cost level may be displayed from highest cost to lowest cost.

The end-user may for example drag those icons I1-I4 which he/she selects and would like to schedule, to a preferred carbon dioxide emission level for that icon to thereby associate the loads with at least one carbon dioxide emission level C1-C4. The end-user may for example be able to configure at which intensity a lighting system should be allowed operate at a determined carbon dioxide emission level. Similarly the end-user may for example drag those icons I1-I4 which he/she selects and would like to schedule, to a preferred end-user cost levels for that icon to thereby associate the loads with at least one end-user cost level L1-L4. The end-user may for example be able to configure at which intensity a lighting system should be allowed operate at a determined end-user cost level.

The user interface graphics lid may, when the schedule for the energy delivery to the at least one load has been determined, further indicate an operating pair P comprising a carbon dioxide emission level C1-C4 and an end-user cost level L1-L4 that corresponds to the determined schedule. One operating pair Pi may be based on the combination (Ci, L4), a second operating pair P2 may be may be based on the combination (C2, L3), a third operating pair P3 may be may be based on the combination (C3, L2), and a fourth operating pair P4 may be may be based on the combination (C4, Li). However, as the skilled person understands there may be more than four levels of carbon dioxide emission levels, more than four levels of end-user cost levels, and more than four operating pairs. Further, these are just example of some possible pairs. Hence, since the icons associated with, say, Ci do not necessary correspond to the icons associated with, say, L4 the icons in the operating pair are preferably determined from the weighting. Hence, if the carbon dioxide emission level has a higher weight than the end-user cost level, the icons represented by the operating pair (Ci, L4) would weighted in favour of carbon dioxide emission level, as for the operating pair P in Fig 3d. The indicated operating pair P is thus a consequence of the weighting determined from the user input as disclosed above with references to Figs 3b and 3c. The end-user is thereby made aware of which strategy is used for the energy management (e.g., based on price, C0₂ emission, etc.).

The determined schedule may be associated with a start time and a stop time. The input unit 3 may thus be arranged to receive the start time and the stop time from the user interface. Likewise, the input unit 3 may be arranged to receive starting time requests from the loads which the energy management unit 1 is arranged to schedule operating times for. When the energy

management unit 1 receives requests of starting times from user-input, the energy management unit 1 can provide starting time data to the loads based on the determined schedule to thereby obtain operation according to the end- user's preferences. An example of a suitable time period may for example be 24 hours. The schedule may comprise a plurality of time slots which together form the time period. A time slot may for example be one hour. An end-user may also by means of interaction with the user interface UI generate a revised scheduling of the selected load. Thus, in a step S8, a starting time for delivery of energy to the at least one load associated with the determined schedule may be provided. A user input of revised scheduling for one or more loads of the at least one load can thereby be received by the energy management unit 1, wherein the above steps associated with determining is repeated based on the end-user input so as to determine a revised schedule for the energy delivery to the at least one load based on the weighting of the at least two parameters. The end-user is thereby enabled at any time to change his/her preference of strategy. For each time slot, the loads may thus operate according to a specific schedule. Additionally, different schedules for energy delivery may be devised for different kinds of loads. For example, lighting devices may be associated with a first schedule for energy delivery and heating devices may be associated with a second schedule for energy delivery. The first and second schedule for energy delivery may be determined as outlined above and implemented and run simultaneously in the same building automation system.

It is envisaged that the methods and energy management unit presented herein may be used in existing grid system as well as in future smart grid systems.

The inventive concept has mainly been described above with reference to a few examples. However, as is readily appreciated by a person skilled in the art, other embodiments than the ones disclosed above are equally possible within the scope of the inventive concept, as defined by the appended claims.

Claims

1. A method of determining a schedule for energy delivery to at least one load in a building automation system, comprising the steps of:

acquiring (Si) an association between at least two parameters and a schedule for delivery of energy to at least one load in accordance with acquired energy need for the at least one load, each one of the at least two parameters relating to priority of a respective property associated with the delivery of energy;

receiving (S4) end-user selection data relating to weighting of the at least two parameters for the at least one load; and

determining (S5) the schedule for the energy delivery to the at least one load based on the weighting of the at least two parameters.

2. The method according to claim 1, further comprising

delivering (S6) energy to the at least one load according to the determined schedule.

3. The method according to claim 1 or 2, wherein a first parameter of the at least two parameters relates to carbon dioxide emission statistics associated with the energy to be delivered to the at least one load.

4. The method according to claim 3, further comprising

receiving (S2) carbon dioxide emission statistics from a service provider of the energy to be delivered prior to acquiring the association between the at least two parameters and the schedule.

5. The method according to claim 3 or 4, wherein the first parameter is associated with a carbon dioxide emission level (Ci, C2, C3, C4).

6. The method according to any one of the preceding claims, wherein a second parameter of the at least two parameters relates to a cost per time unit of the energy to be delivered to the at least one load, the cost being payable by an end-user of the building automation system.

7. The method according to claim 6, further comprising receiving (S3) cost per time unit statistics from a service provider of the energy to be delivered prior to acquiring the association between the at least two parameters and the schedule.

8. The method according to claim 6 or 7, wherein the second parameter is associated with energy cost level data of a plurality of energy cost levels that are based on energy cost statistics.

9. The method according to any one of claims 3 to 8,wherein the energy delivery comprises delivery of a first kind of energy, the first kind of energy being associated with high priority of the first parameter and low priority of the second parameter.

10. The method according to claim 3 to 9,wherein the energy delivery comprises delivery of a second kind of energy, the second kind of energy being associated with high priority of the second parameter and low priority of the first parameter.

11. The method according to claim 9 and 10, wherein amounts of the first kind of energy and the second kind of energy is delivered in accordance with the weighting.

12. The method according to any one of the preceding claims, further comprising

providing (S7a, S7b) a current energy consumption level of the load to a user interface prior to and/or after the step of receiving end-user selection.

13. The method according to 12, wherein the current energy consumption level further comprises a forecast for a future energy consumption level based on the end-user selection data.

14. The method according to any one of the preceding claims, wherein the building automation system is a building automation system for use in a residential home or in an office building.

15. The method according to any one of the preceding claims, wherein the at least one load relates to a heating functionality, a lighting functionality, and/or electricity consumption of the building automation system.

16. The method according to claim 15, wherein different schedules for energy delivery are determined for different types of loads.

17. The method according to any one of the preceding claims, further comprising

providing (S8) a starting time for delivery of energy to the at least one load associated with the determined schedule.

18. A computer program for determining a schedule for energy delivery to at least one load (L) in a building automation system (9), the computer program comprising computer program code which, when run on a energy

management unit (1), causes the energy management unit to

acquire (Si) an association between at least two parameters and a schedule for delivery of energy to at least one load in accordance with acquired energy need for the at least one load, each one of the at least two parameters relating to priority of a respective property associated with the delivery of energy;

receive (S4) end-user selection data relating to weighting of the at least two parameters for the at least one load; and

determine (S5) the schedule for the energy delivery to the at least one load based on the weighting of the at least two parameters.

19. A computer program product comprising a computer program according to claim 18 and a computer readable means on which the computer program is stored.

20. An energy management unit (1) for determining a schedule for energy delivery to at least one load in a building automation system (9), comprising a processing unit (4) arranged to acquire an association between at least two parameters and a schedule for delivery of energy to at least one load (L) in accordance with acquired energy need for the at least one load, each one of the at least two parameters relating to priority of a respective property associated with the delivery of energy;

an input unit (3) arranged to receive end-user selection data relating to weighting of the at least two parameters for the at least one load; and

the processing unit (4) further being arranged to determine the schedule for the energy delivery to the at least one load based on the weighting of the at least two parameters.