WO2016029942A1

WO2016029942A1 - Method to control a flow of energy between a grid and a local system

Info

Publication number: WO2016029942A1
Application number: PCT/EP2014/068181
Authority: WO
Inventors: Alessandro Giusti; Matteo Salani; Andrea Emilio Rizzoli; Luca Maria Gambardella; Gian Carlo Dozio; Fabio Foletti; Davide Rivola; Roman Rudel; Marco BELLIARDI; Lorenzo NESPOLI; Vasco MEDICI
Original assignee: Alpiq Intec Ag
Priority date: 2014-08-27
Filing date: 2014-08-27
Publication date: 2016-03-03

Abstract

A method to control a flow of energy between a grid and a local system is disclosed. The local system includes - means to produce energy locally and/or - means to store energy produced locallyor to absorb energy from the grid and/or - means to consume energy produced or stored locally or absorbed from the grid. The method stores in the local system information on - energy produced locally in the past and/or - energy suppliedto the grid in thepast and/or - a load of the grid in the past. The stored information is used to program, in the local system, next - storages of the energy and/or - consumptions of energy and/or - supplyof energy to grid.

Description

TITLE: Method to control a flow of energy between a grid and a local system. Field of application

The present invention relates to a method to control a flow of energy between a grid and a local system. More particularly, the present invention relates to a method of the type referred above wherein the local system includes one or more electrical devices, for instance photovoltaic panels, bidirectional batteries, accumulators, boilers, heating or cooling systems, heat pumps, home appliances, and wherein the flow of energy between the electric devices and the gird is controlled, preferably to reduce cost of energy for the user in the local system or to reduce a load on the grid or to satisfy different requirements.

The present invention also relates to a system for controlling a flow of energy between a grid and a local system.

Prior art Known methods and systems to control a flow of energy between a grid and a local system are based on a communication of information between the grid and electrical devices in the local system.

Some information are retrieved in the local system, monitoring locally the electrical devices, and are sent to the grid, for instance to a grid controller that collects the information to know and better manage the requests of electrical energy.

Some other information are retrieved by the grid, for instance through the grid controller, measuring a load of the grid.

The controller adapts the supply of energy to the local system on the base of the load of the grid and/or the information previously received from the local system. For example, the controller may reduce supply of energy if the load of the grid is high; the reduction may be obtained selecting devices in the local system whose supply of energy may be delayed and postponing the supply to such device. The known methods and systems are useful, especially in consideration of the increasing number of electric appliances requesting energy to the grid and the limited capacity of the grid.

However, they suffer for some limitation, especially associated to their complexity, difficult integration within the local system, cost and low efficiency.

In this respect, a communication network is required to send information between the electrical devices and the grid controller. This means that all the devices or at least a control device in the local system must be provided with a communication interface with the grid. However, in the local system is not always available a network connection.

Moreover, to implement the known method, the device in the local system must be provided with sensors, to detect information to be transmitted to the grid controller. However, several devices commonly used in local systems are not provided with sensors to measure data for the grid. For instance, known rechargeable battery have no sensor for measuring the state of charge of the battery. Thus, it is not possible to send information to the grid on the battery level.

Furthermore, the known methods are not efficient because not adapted to improve energy management and costs, especially when also the local system is provided with means to produce energy, for instance with a photovoltaic panel system. In this case, may happen that energy produced locally is completely transferred to the grid at production time; this is disadvantageous, especially because the local system must require energy to the grid, when no local production of energy is available (for instance at night time).

In other words, the known method and system are not adapted to improve the autonomy of the local system, i.e. reducing the exchange of energy with the grid, to the benefit of the costs for the used and also of the load the grid.

The problem at the base of the present invention is that of providing a method and a system to control the flow of energy between the local system and the grid, improving the use of energy through different means (devices) that produces, consumes or stores energy in the local system, wherein the method and system may be easily applied to devices and appliances already installed in the local system, reducing the load of the network and/or the cost of the energy for the user, thus solving all the limitations that currently affect the prior art method and devices. Summary of the invention

The idea of solution at the base of the present invention is that of

-estimating future usages U of energy in a local system S, for instance when and how much energy will be consumed, produced or stored in respective devices D in the local system S, and -using the estimated usages U to program the flow of energy in the future, to/from the devices D and to/from a grid G.

Programming the flow of energy is made to satisfy one or more requirements, for instance to optimize the future usages U of energy in term of

-reduction of the costs for the users in the system S and/or -reduction of the load L on the grid G and/or

-minimization of energy exchanges among the local system S and the grid G.

In an aspect of the present invention, a control device C is installed in the local system S and is configured to control one or more of the devices D and also to control the gird G. The control device C is adapted to save a history of usages of the devices in the local system S, save a history of loads L of the grid S, estimate future usages U of the devices and loads L of the grid G and program the flow of energy to and from the grid G.

Saving the above mentioned histories includes measuring locally a flow of energy through each of the controlled devices D and measuring, always locally, a load L of the grid G. In this respect, according to the present invention, the load L of the grid G is associated to a voltage of the electric power supply measured locally, i.e. in local system S.

Estimation of future usages U of energy or loads L of the grid G is based on a pattern of past usages U and/or a pattern of past loads L.

A pattern is a regularity (in the past usages or loads) which is detectable through the controller C. The past usages of energy or loads L of the grid G in the pattern repeat in a predictable manner in the future. Thus, repetition of past usages or loads L in the patterns is used to estimate future U usages or loads L, and to determine, within the future usages, also values of flows of energy between the devices D of the local system L and the grid G or values of the load L of the grid G.

According to the idea mentioned above, once a pattern of future usages U and loads L is determined, the control device C may program the devices D in the local system S to produce, consume or store energy with optimization of loads L and/or costs.

For instance, energy may be stored in advance in the local system S to be used in the future, avoiding a further request of energy to the grid; similarly, energy may be consumed in advance in the local system S with respect to a real user request, in order to reduce the energy consumed in the future for satisfying the real user request; in another example, a flow of energy from the local system S to the grid G may be programmed in case the load L of the grid G is too high.

According to this solution idea, the technical problem is solved by a method according to claim 1. In particular, according to an aspect of claim 1 , the method may control the flow to be as low as possible, for instance and if possible, no flow between the grid and the local system.

The dependent claims relates to advantageous embodiments of the method of claim 1. Further features and advantages of the method and device according to the present invention will be give in the following description, given with reference to the annexed drawings only for exemplification and without limiting the scope of protection of the present invention. Brief description of the drawings

Figure 1 is a diagram block schematically representing functional modules for implementing a method to control a flow of energy between a grid and a local system, according to an embodiment of the present invention.

Figure 2 is a flow diagram schematically representing a flow of energy controlled according to the method of figure 1.

Figure 3 is a diagram representing an estimation of a power produced by photovoltaic panels in the local system of figure 1 , as a function of time.

Figure 4 is a diagram representing the estimation of power of figure 3, on a first curve, and an absorption of power in a battery connected to the photovoltaic panels, as a function of time, on a second curve, according to a first control of the flow for reducing charging time of the battery.

Figure 5 is a diagram representing the estimation of power of figure 3, on a first curve, and an absorption of power in a battery connected to the photovoltaic panel, as a function of time, on a second curve, according to a second control of the flow for reducing power exchanged with the grid.

Figure 6 is a diagram representing the estimation of power of figure 3, on a first curve, and an absorption of power in a battery connected to the photovoltaic panel, as a function of time, on a second curve, according to a third control of the flow for further reducing power exchanged with the grid, wherein energy is also stored in a boiler as heat.

Figures 7 and 8 schematically represent different estimations of energy produced by photovoltaic panels according to different forecasted weather conditions.

Detailed description of the invention According to the present invention a method and a system to control a flow of energy between a grid G and a local system S is provided.

Hereafter, the term local system S is used to relate to a place or a building, for instance a house or an industry, including a local electrical grid and at least a device D connected to the electrical grid, for instance a battery for absorbing energy, a heating or cooling system, an electrical boiler, a heat pump consuming energy, a photovoltaic panel system for producing energy, a bidirectional battery for absorbing or providing energy, an electric vehicle to be recharged etc..

The local electrical grid is connected to the grid G and may absorb electrical energy from the grid G at a predetermined price or supply electric energy to the grid G.

The list of devices D mentioned above is not exhaustive and the local system S may include substantially any

-means adapted to produce energy locally and/or any

-means adapted to store energy produced locally or to absorb energy from the grid and/or any

-means adapted to consume energy produced or stored locally or absorbed from the grid.

For conciseness, in the following description the above mentioned means for "producing, storing and consuming energy" are also referred with "controlled means" and are indicted with D.

More particularly, the controlled means D include "electrical" devices, i.e. devices taking electrical energy directly from the local system S or from the grid G, or supplying electrical energy to the grid G or to the local system S. Such electrical devices are for instance photovoltaic panels (PV), home appliances, such as a washing machine or a microwave oven, or non controllable loads, such as television system, computer, etc.

The term "energy" encompasses other energy, just to cite some, heat or chemical energy. Thus, in this respect, the controlled means D may be read also as devices for storing energy different from electric energy, for instance for storing heat in a water tank or in a space or room, as hot air, or devices storing chemical energy, such as a battery system.

The method of the invention is characterized by storing, in the local system S, and more particularly in a control device C installed in the local system S, a plurality of information regarding past usages of the controlled means. For instance, information on

-energy produced locally in the past and/or

-energy supplied to the grid in the past and/or -a load L of the grid G in the past.

In order to retrieve this information, the control device C is connected to the controlled means (i.e. PV) through the local electrical grid and includes a detector for measuring how much energy has been produced or supplied from the controlled means D. For instance, the detector controls an activation time of the controlled means D and how much energy pass to the controlled means D or from the controlled means D in the activation time.

The information stored in the control device C is used to program, in the local system,

- next storages of the energy and/or - next consumptions of energy and/or

- next supply of energy to grid.

Also in the above mentioned step of programming, the term "energy" includes electrical energy -since the control device C may program absorption, consumption or supply of electrical energy from the grid G to the electrical device D and vice versa- and also includes other kind of energy which may be controlled: for instance, the control device C may program storage of energy in the form of heat, in a water tank or in a room to be conditioned or heated. The information stored in the control device C, i.e. locally within the local system S, also include

-energy stored in the past and/or

-energy consumed in the past, and also these information are used for programming the controlled means in the local system.

More particularly, the information stored in the local system S is detected locally, for instance measuring how much energy has been consumed (stored), the time period in which it has been consumed (stored) and with an identification information ID of the device having consumed the energy, for instance as follows:

Controlled mean idl , amount of energy x, action: consumption, time: tl-t2

Controlled mean id2, amount of energy y, action: storage, time: t3-t4

Controlled mean id3, amount of energy z, action: production, time: t5-t6 wherein "id" identifies the controlled means D (Boiler, battery, PV, etc) in the local system S, and x,y,z are the amount of energy consumed, stored or produced (action) in a corresponding time frame or period (activation period).

Advantageously, no communication with the grid G is required to detect the information on past usages of energy or to estimate future usages U of energy.

In an embodiment of the invention, the control device C is implemented with a central hardware electrically connected to the controlled means D in the local system S, i.e. through the local electrical grid.

In another embodiment of the invention, the control device C is implemented with a plurality of hardware, each installed with a corresponding controlled mean D and interconnected locally with the control device C, for transmission and receipt of information and instructions.

The hardware may have a double interface: one interface adapted to be plugged at a power outlet of the local electrical grid in the system S and the other adapted to be connected to the controlled means D. Advantageously, no modification is required to the controlled means D already installed in the local system S, for instance to an old PV system, an old boiler or a standalone battery; indeed, all the measurements are made in the hardware plugged or connected to the controlled means D and are transmitted from this hardware to the control device C in the local system S. Thus the controlled means D may work as usual and be unaware of the instruction or commands received from the hardware or control device C.

In this respect, according to an aspect of the present invention, these instruction may be turn on / turn off commands, for instance to suspend consumption or storage of energy in the controlled means D.

According to the method, also information on the grid G are detected or measured without communicating to the grid G. More particularly, the load L of the grid in the past is associated to a value of an electric current detected at a point of connection of an electrical grid of the local system S, said value being preferably a voltage of the electric power supply measured locally. In this respect, according to the method, a first voltage VI measured locally is associated to a first load LI which is lower than a second load L2 associated to a lower voltage V2. In other words, decreasing voltage is read as increasing load of the grid G.

Voltages are stored to build a database of loads, i.e. patterns of loads L, and the database of loads are used to estimate loads L of the grid G in the future.

Energy flows, i.e. production of energy, consumption of energy and storage of energy, are stored to build a database of flows, i.e. patterns of flows, and the database of flows are used to estimate flows of the energy in the future.

In this respect, the step of programming includes estimating a

-future storage of the energy and/or

-future consumption of energy and/or

-future supply of energy to grid and/or

-future production of energy and programming the next storage, consumption and supply on the base of the estimated storage, consumption or supply.

In an embodiment of the invention, programming the consumption and storage is made in advance with respect to a future estimate usage U.

For instance, the method may estimate that the user will request a conditioned or heated air at temperature T (20°C or 28°C) from 20:00 to 23:00 and program in advance the conditioning or heating of air, for instance starting at 16:00, when the PV produce a lot of energy, in order to start decreasing the temperature to the desired temperature (20°C) or increasing it at the desired temperature (28°C) in advance, using energy produced in the local system with no expenses. This is preferred than taking energy from the grid when the conditioning or heating is requested by the user (at 20:00), since the PV does not produce sufficient energy.

In this respect, the method to program the flow is independent from the control onboard to the controlled means D, for instance the thermostat of a boiler of a heating pump. In other words, the method intervenes on the base of historical data stored in the past and on the base of estimation, not on the base of programming or parameters of each controlled device.

According to another aspect of the invention, the method receives also information not directly associated to the local system devices, in order to improve the programming. Such information includes, for instance, weather forecast, to better estimate the future production of energy through PV with weather forecast.

For example, if a sunny day at 30 °C is forecasted in summer, the method may program a flow of energy from the local system (PV) to the grid between 12:00 and 15:00, in order to help the grid, in case the grid is estimated to be overloaded due to several conditioning system requesting energy at that time. This supply may be programmed especially if the PV in the local system are not used locally, for instance because the user is not at home (this information is for example estimated on the base of few power absorption in the local system, i.e. no usage of conditioned air) or because no conditioned system is available in the local system. Such a supply of energy programmed between 12:00 and 15:00 is not detrimental for the local system S, even in case some energy is required later, for instance between 18:00 and 22:00, i.e. when the user is at home. Indeed, the method estimates that the energy produced by PV after 15:00 is sufficient to satisfy the energy requested from the local system. Thus, the exchange of energy between the local system S and the grid G is null or reduced and, at the same time, the local system S helps the grid G to satisfy the high requests of energy (coming from other system S') between 12:00 and 15:00.

On the contrary, in case the weather forecast is for a cloudy winter day at 8°C and the estimated usage U of energy consumption in the local system S is high, because the heating system (for instance a heating pump or a boiler) is scheduled to start heating at 17:00, i.e. one hour before the user comes home, the method programs a storage of all the energy produced by PV in a bidirectional battery in the local system S, if available, and start supplying energy from the battery to the heating system when programmed, i.e. at 17:00.

If a bidirectional battery is not available or not configure in the control device C, the method of the invention may program heating in advance, for instance at 14:00, using energy produced by PV with zero cost, in order to reduce the energy that will be eventually required to the grid G to heat the temperature at 17:00.

This program also reduces the load on the grid, since it reduces the energy requested from the local system to the grid when the grid is estimated to be overloaded by heating systems, i.e. after 18:00.

In this respect, according to the invention, the estimation of the load of the grid may be improved considering the weather condition: in a cold winter day (for instance -5 °C at 8:00 a.m., external temperature) the request of energy to the grid from the heating system is estimated to be less than the request in a warmer winter day (for instance 2 °C at 8:00 a.m.). In order to optimize the cost for the user, the method further include taking in input a schedule of cost of energy from the grid and programming consumption, storage and supply of the energy to minimize the cost in the local system.

According to what explained before with reference to the method for controlling the flow of energy, the present invention also provides a system to implement the method.

The system includes

-means to produce energy locally and/or

-means to store energy produced locally or to absorb energy from the grid and/or

-means to consume energy produced or stored locally or absorbed from the grid; and is characterized by the fact that it is installed locally and includes means to store information on

-energy produced locally in the past and/or -energy supplied to the grid in the past and/or -a load of the grid in the past and means to program, on the base of the stored information, next -storages of the energy and/or -consumptions of energy and/or -supply of energy to grid.

In an embodiment of the present invention, the system is a control device electrically connected to the electrical local grid of the local system.

With reference to drawings 1-8, is hereafter described the method of controlling the flow of energy according to an embodiment of the present invention which is however given without limiting the scope of protection of the invention and only with exemplification purpose. In this example, the local system is a household equipped with photovoltaic panels (PV) and with a bidirectional battery for energy storage. Optionally, one or more controllable energy buffers are available in the household, for instance a boiler with a water tank or a space to be heated or conditioned; in this respect, the controllable energy buffers include, for instance, accumulators of electric energy, and also buffer of other kind of energy, for instance heat, such as the heating tank of the boiler or the space to be heated or conditioned. Additional non-controllable loads may be connected to the household electrical grid, for instance a television or personal computers.

According to the method of the invention, the energy exchange from/to a grid and the household is reduced setting at least one of the following requirements to be satisfied, separately or together: a) minimization of a price paid for energy by the user. b) minimization of the impact on the grid of the energy requested by the user and/or minimization of the energy injected into the grid .

In this respect, when a) and b) are set together, the reduction of the price for the user (requirement a) and the impact on the grid (requirement b) cannot be satisfied as much as when a) and b) are set separately. According to the method of the invention, requirements a) and/or b) and/or further requirements are set in a set up phase of the method, for instance through a control panel, wherein requirements may be selected and set.

The method is executed locally, i.e. within the local system, for instance through a control device (C) installed in the local system, wherein the control panel is accessed as a user graphical interface. The control panel is also used to configure the hardware to be controlled in the local system (S), including for instance (PV), bidirectional battery for energy storage, boiler, heating or conditioning means, etc, which are connected to the control device.

Depending on the requirements a) and/or b) and/or further requirements, the method controls the flows, for instance: -it draws energy when there is plenty of energy in the grid (G); and/or

-instead of transferring power produced through PV to the grid in the afternoon (or when production is high) and then using power from the grid in the evening (or when the production is low), it stores locally the energy produced by PV in the afternoon (i.e. when production is high), thus minimizing the total amount of energy exchanged with the grid; and/or

-it minimizes the maximum amount of power exchanged with the grid.

According to the available hardware, i.e. depending on the devices (D) to be controlled and set up in the configuration phase, the method: -determines when charge, leave idle or discharge the bidirectional battery;

-determines the control actions for energy buffers, for instance i) when the space heating means, i.e. an heat pump or conditioning means, should be turned on/off, to keep the ambient temperature within a required range; ii) when the water heating means, for instance the electric boiler or the heat pump, should be turned on/off, to keep the water temperature within the required range.

The method estimates the time when the user will turn on the conditioned air and when he will turn off, as well as the temperature set in the conditioned room. Depending on the load of the grid and on the amount of energy produced by PV before the estimated usage of the conditioned air, the method may cool the house or a room in advance with respect to the estimated usage, i.e. using energy produced locally instead of absorbing energy from the grid.

Similarly, the method may estimate when heating system, for instance a heating pump or a boiler, are turned on to heat home or a room and program the heating means in advance, if local energy produced by the PV is available. In this way, the temperature in the house is maintained more approximate to the estimate temperature required by the user, also when the user is outside. Indeed, the local consumption of energy locally produces may be more convenient than buying energy from the grid, even if the amount of energy locally consumed is more than the amount of energy from the grid.

According to the method, the energy produced locally may be also stored and not immediately consumed. This is particularly advantageous because the energy stored locally prolongs the length of time in which the local system is autonomous respect to the grid, also when the local production of energy is stopped, for instance in absence of sun or at night time.

In this respect, the storage of energy includes not only electric energy in a battery or accumulator, but also other form of energy, including heat. For instance, energy produced by PV is used to heat the temperature in a boiler tank, also when no hot water is required from the user or necessary to satisfy the local needing. Energy stored as heat, is however used in the future, for instance when the user will require hot water or when the PV will not produce energy, avoiding a request of energy to the grid.

In order to control the flow of energy, the method forecasts a plurality of information or variables. For example, to choose whether charging the battery at a time t, how much energy will be available in the grid at time interval after t is estimated and how much energy the PV will produce in such time interval is estimated.

In this respect, the method executes forecasting modules to predict a future evolution of such critical variables, including: y) Forecasting of PV production. This estimation is based on historical data, machine learning, if available using external sensors and/or communication, such as weather forecast on the Internet. yy) Forecasting of future voltage drops, to estimate the state load of the grid. This estimation is made measuring the voltage of the energy power supply measured locally. For instance, according to the example at figure 3, at 9:00 AM (now), the method estimates the PV output for the following 12 hours.

Based on the estimation and on the set up phase mentioned above, the method may implement a baseline control strategy wherein the battery is fully charged as soon as possible, as schematically represented with the continued line in figure 4. After the battery is fully charged at 13:30, the full PV output is controlled to flow towards the grid. This control is advantageous for example if the cost of energy from the grid is high between 9.00 and 13.30 and thus is not convenient to load the battery with energy from the grid; moreover is convenient if only the battery is available or connected in the local system between 9:00 and 13:30 and thus no energy may be absorbed from other devices. In this respect, the devices connected at a time t are detected with the control device.

According to another control of the flow, which is configured in the set up phase when more energy buffers are available, the method minimize the exchange of energy with the grid, as schematically represented in figure 5. The battery is also in this case fully recharged but along a longer time interval, for instance ending at 18.00, so that the energy produced by PV in the peak time (around 13) is not introduced in the grid but controlled to be at least partially used locally, for instance to charge the battery or for other appliances at home, for instance for the boiler, as schematically represented in figure 6. This control is advantageous for example when not only the battery but also other appliances may absorb energy; indeed, not all the energy at a time t is absorbed by the battery but a part of the energy produced locally is used for other needs; however, also in this case the battery is fully charged before daily production of energy, so that the energy stored in the battery may be used at night time or when requested.

In this respect, with a forecast on the load of the grid, the method further optimizes the use of energy, shifting energy exchanges with the grid towards time periods where more energy is available. For instance, if the estimated voltage (load of the grid) is estimated to be very low between a time interval, for instance between 15.00 and 18.00, the method programs the charge of the battery in advance so as to exclude it recharge during 15.00 and 18.00. In this case, at least part of the energy stored in the battery and/or produced in the PV may be given to the grid 15.00 and 18.00, to reduce its load.

In case a communication channel or network is available in the local system to communicate with an energy company, the method may for example: x) receives preferred energy use times (overrides grid state forecast). xx) transmits forecast (estimated) energy use.

In this way, the energy company can modulate the energy use of consumers by providing information. Such information are not direct command like instruction to charge the battery but instead used by the local device controller to improve programming the flow of energy.

Advantageously, the method is modular, i.e. it may be executed with a plurality of modules or with a subset of said plurality of modules.

Technology choices can be made in such a way that a single appliance will behave appropriately, and will explicitly coordinate with other devices if they are detected in the same household (e.g. through power line communication). For example, a single energy buffer may optimize its behaviour even if the household has no installed PV and no available battery. Similarly, the method controls the battery even when no controllable energy buffers are available.

Prediction of the PV production profile can be implemented using machine learning techniques and time series forecasting techniques. The method continuously monitors the PV output, thus learning the normal output profiles (also accounting for the time of year). In addition, PV outputs also depend on weather conditions; thus, correlation among the output in the early morning with the outputs later in the day can be exploited to produce a probabilistic estimation of the future output of the PV. In this respect, a known correlation among the state of the sky during the morning and a state of the sky later in the afternoon may be used. Figure 7 represents the estimation at 9:00 in a sunny day compared with the estimation at the same time of an overcast day.

Returning to the example given above, if the voltage (load of the grid) is estimated to be very low between the time interval, for instance between 15.00 and 18.00, and in further consideration of the estimated weather condition (fig. 7 or 8), the method may program the charge of the battery in advance so as to exclude its recharge during 15.00 and 18.00 (fig. 7) or so as to continue its recharge also during 15.00 and 18.00 (fig. 8). In the former case, at least part of the energy stored in the battery and/or produced in the PV may be given to the grid between 15.00 and 18.00, to reduce its load; in the latter case, no energy stored in the battery and/or produced in the PV is given to the grid, since the energy produced locally is estimate to be totally necessary for recharging the battery and since an absorption of current from the grid to recharge the battery is estimated to be not appropriate, due to the high estimated load of the grid.

Advantageously, according to the present invention, a method and a device to control the flow of energy and to improve production, consumption and storage to the benefit of the user and/or the gird is provided. The method is advantageously based on information detected or estimated locally, i.e. in the local system wherein energy is locally, produced, stored or consumed, and does not require a communication network. The estimated information are based on data stored locally in the past, mainly time and energy produced, consumed, stored by the local hardware devices, and the programming of flow of energy is also made locally, on the base of estimated information. The method and system may work without sensors on the devices to be controlled locally, since the information stored and estimated may be based only on the amount of power absorbed by the device to be controlled and the corresponding time period or frame. A control device connected to the devices to be controlled locally stores power absorbed by the device to be controlled and the corresponding time period or frame, estimate future absorption and time frame and program the device to optimize the use of energy and/or the costs.

Claims

1. Method to control a flow of energy between a grid and a local system including -means to produce energy locally and/or -means to store energy produced locally or to absorb energy from the grid and/or -means to consume energy produced or stored locally or absorbed from the grid; characterized by storing in the local system information on -energy produced locally in the past and/or -energy supplied to the grid in the past and/or -a load of the grid in the past wherein said stored information is used to program, in the local system, next -storages of the energy and/or -consumptions of energy and/or -supply of energy to grid.

2. Method according to claim 1 characterized by the fact that

-said the means to produce energy locally includes photovoltaic panels,

-said means to store energy locally includes a bidirectional battery, an accumulator, a boiler tank, a space to be heated or conditioned, -said means to consume energy locally includes a boiler, a heating system, a heat pump, a home appliance or a non controllable load device.

3. Method according to claim 1 characterized by further storing, in the local system, information on -energy stored in the past and/or -energy consumed in the past, and wherein said further information is used in said step of programming.

4. Method according to claims 1 or 3 characterized by the fact that said information stored in the local system is detected within the local system.

5. Method according to claim 4 characterized by the fact that said information on a load of the grid in the past is associated to a value of an electric current detected at a point of connection of an electrical grid of the local system, said value including a voltage of the electric power supply measured locally.

6. Method according to claim 1 characterized by the fact that said step of programming includes estimating

-future storage of the energy and/or -future consumption of energy and/or

-future supply of energy to grid and/or

-future production of energy and wherein the next storage, consumption and supply is programmed on the base of the estimated storage, consumption or supply.

7. Method according to claim 6 characterized by the fact that said step of estimating the future production of energy includes receiving an information on a weather forecast and forecasting a production of energy associated to the weather forecast.

8. Method according to claim 1 characterized by the fact that said step of programming includes taking in input a schedule of cost of energy from the grid and programming consumption, storage and supply of the energy to minimize the cost in the local system.

9. Method according to claim 1 characterized by the fact that said step of programming includes taking in input an estimated future schedule of load on the grid and programming consumption, storage and supply of the energy to minimize the load.

10. Method according to claim 1 , wherein the local system is a home or an industrial grid.

1 1. System to control a flow of energy between a grid and a local system, the local system including

-means to produce energy locally and/or -means to store energy produced locally or to absorb energy from the grid and/or

-means to consume energy produced or stored locally or absorbed from the grid; characterized by the fact that the control system is installed locally and includes means to store information on

-energy produced locally in the past and/or -energy supplied to the grid in the past and/or

-a load of the grid in the past and means to program, on the base of the stored information, next -storages of the energy and/or -consumptions of energy and/or -supply of energy to grid.