WO2004045044A1

WO2004045044A1 - A plant for the exploitation of renewable energy sources in combination with traditional energy sources, particularly for the heating and cooling of dwellings

Info

Publication number: WO2004045044A1
Application number: PCT/IT2003/000613
Authority: WO
Inventors: Walter Cassani; Alessandro Scarioni
Original assignee: Walter Cassani; Alessandro Scarioni
Priority date: 2002-11-14
Filing date: 2003-10-10
Publication date: 2004-05-27
Also published as: ITMI20022414A1; AU2003279538A1; EP1563581A1

Abstract

A plant (15) for dwellings (10) , adapted to interacting with the power mains (35) of the dwelling (10) and comprising means of generating electrical energy (20) suited to producing electrical energy, and an inverter device (40) adapted to receiving the electrical energy produced by the means of generating electrical energy (20) and of sending it to at least one air conditioning device (95) for the dwelling (10). The air conditioning device (95) comprises a heat pump (100) and a converter device (110) adapted to receiving the electrical energy from the inverter device (40) or from the power mains (35) and of altering the parameters of the electrical energy for the regulation of the air conditioning device (95). The air conditioning plant (15) is adapted to feeding into the power mains (35) of the dwelling (10) the electrical energy produced by the means of generating electrical energy (20) when the electrical energy produced by the generating means (20) exceeds the energy requirements of the air conditioning device (95).

Description

"A PLANT FOR THE EXPLOITATION OF RENEWABLE ENERGY SOURCES

IN COMBINATION WITH TRADITIONAL ENERGY SOURCES,

PARTICULARLY FOR THE HEATING AND COOLING OF DWELLINGS"

DESCRIPTION [0001] The object of the present invention is a plant for the exploitation of renewable energy sources in combination with traditional energy sources, particularly designed for the heating and cooling of dwellings; a further object is a method for the production and distribution of electrical energy to the dwellings electrical appliances, and is particularly adapted to implementing the air conditioning for the dwellings. [0002] Renewable energy plants, for example solar or wind, used for supplying electrical power plants for the illumination of dwellings, as well as other electrical uses, are known.

[0003] Solar energy is particularly easy to use, even at the domestic level, through solar panels, for example photovoltaic panels, which allow the attainment of "clean" electrical energy.

[0004] The exploitation of solar energy is nevertheless made traditionally problematical by the fact that such energy is obviously only available during the hours of sufficient sunlight and hence the problem arises of making such energy also available during the night-time hours and in any case when solar radiation is not sufficient. [0005] A similar problem also occurs with wind generators, which are only able to supply energy when the wind is of a sufficient intensity. [0006] The most obvious solution to such a problem is that of creating an energy accumulator and indeed various systems for accumulating the energy produced in excess for its exploitation during the hours in which it is not generated have been proposed. [0007] The accumulation systems are nevertheless complicated and costly and make the exploitation of solar, or wind, energy not very convenient, above all at the domestic level, in relation to the cost of the traditional electrical energy available through the grid. [0008] The task of the present finding is that of providing a plant, and the relevant method of use, for the exploitation of renewable energy sources, particularly for the heating and cooling of dwellings, which overcomes the problems of the traditional electricity generating plants for private use.

[0009] Within the scope of this task, one aim of the finding is that of providing a plant which allows the economically advantageous exploitation of renewable energy. [00010] This and other aims are achieved with a plant in agreement with claim 1.

[00011] Another useful result is that of providing a plant with reduced installation and management costs and therefore easily redeemable with respect to the traditional energy sources.

[00012] These aims and others, which will appear more clearly below, are achieved by a plant for the exploitation of renewable energy sources in combination with traditional energy sources, particularly for the heating and cooling of dwellings, comprising means of generating renewable energy, adapted to producing electrical energy which is introduced into the domestic grid for supplying various appliances; the plant is characterised by comprising an inverter device suitable for sending the electrical energy, produced by the generating means, to the distribution grid when the appliances do not require such electrical energy. [00013] In addition, such a plant comprises at least one counting meter adapted to measuring the electrical energy produced by the generating means and fed into the distribution grid.

[00014] Further characteristics and advantages of the object of the present finding will appear more clearly by the examination of the description of a preferred, but not exclusive, embodiment of the finding, illustrated as a non limitative indication within the attached drawings, wherein the only figure illustrates a functional diagram of a plant according to the finding, applied to a dwelling. [00015] With reference to the aforementioned figure, by 10 has been generically indicated a dwelling complex to which a plant 15 according to the invention has been applied. [00016] The plant 15 comprises means of generating electrical energy 20, such as for example solar panels, preferably photovoltaic cells 25, mounted in such a manner as to be exposed to sunlight, for example on the roof of the dwelling 10. [00017] Preferably the photovoltaic cells 25 are supplied with an earthing connection 30, for example located within the grounds adjacent to the dwelling 10. [00018] Preferably the photovoltaic cells 25 are electrically connected to electrical transformation means 33, adapted to receiving the electrical energy produced by the energy generating means 20 and to transform it in such a manner as to make it suitable for supplying power mains 35 adapted to making an electrical supply for the dwelling 10. [00019] In addition, the electrical transformation means 33 are adapted to transforming the electrical energy received from the energy generating means 20 in such a way as to make it suited to supplying the electrical appliances 37 of the dwelling 10.

[00020] According to one embodiment, the electrical transformation means 33 comprise at least one inverter device 40. The inverter device 40 is adapted to receiving a direct current from the photovoltaic cells 25 as input, and to sending an alternating current at a desired frequency, for example 50 Hz, as output. [00021] In output, the inverter device 40 is connected to a primary circuit 45 which, through the inverter device 40, receives the electrical energy produced by the energy generating means 20. The primary circuit 45 is connected to at least one electrical appliance 37 through a distribution grid 48.

[00022] Preferably, between the primary circuit 45 and the distribution grid 48 is arranged an electrical control panel 50 adapted to making electrical bypasses or connections to various electrical appliances 37 or to comprising, for example, possible electrical control and inspection devices for the plant 15.

[00023] Preferably, between said primary circuit 45 and the electrical control panel 50, an electrical bypass 55 is formed, electrically connected to the power mains 35 adapted to forming an electrical supply for a dwelling 10. [00024] Advantageously, along said bypass 55 are inserted means for measuring electrical power 65, preferably a power consumption meter 70 and a counting meter 80 which, according to one embodiment, are connected to each other in series.

[00025] In particular, according to one embodiment, the meters 70,80 are connected together in such a manner as to have an inverted direction of measurement; in other words the meter directly connected to the primary circuit 45, i.e. the counting meter 80, is adapted to measuring a current flow which passes from the primary circuit 45 towards the power mains 35; whilst the power consumption meter 70 is adapted to measuring a current flow which passes from the power mains 35 towards the primary circuit 45.

[00026] According to a further embodiment, said means of measuring electrical power 65 comprise a single meter, positioned along the bypass 55, and adapted to measuring the electrical power which flows in both directions, i.e. from the electricity grid 35 towards the primary circuit 45, and vice versa .

[00027] According to one embodiment, the output electrical control panel 50 is electrically connected to the distribution grid 48, adapted to serving the electrical appliances 37 of the dwelling 10. [00028] The electrical appliances 37 can comprise household appliances of any type, preferably adapted to being supplied with an alternating electrical current, coming from the distribution grid 48. [00029] Preferably the electrical appliances 37 comprise at least one environmental conditioning device 95, preferably comprising a heat pump 100 and a converter device 110. [00030] Advantageously, the converter device 110 has the task of receiving the electrical current from the inverter device 40 or from the power mains 35, through the distribution grid 48, and of modifying the electrical parameters of the energy received in order to then supply such energy to the heat pump 100. [00031] In particular, the converter device 110 receives an alternating current of a first frequency, or input frequency, as input from the distribution grid 48, and distributes as output an alternating current of a second frequency, or output frequency which supplies the motor means of the heat pump 100.

[00032] According to one embodiment, the converter device 100 comprises a rectifying device 115 which receives the alternating current at the input frequency and rectifies it into direct current and an inverter 120 which transforms the continuous current into alternating current at the desired output frequency.

[00033] The inverter 120 is also able to change the output voltage to be fed to the motor means of the heat pump 100. The inverter is adapted to continuously regulate the speed of rotation of the motor means of the heat pump 100, in order to adjust the operation of the air conditioning device 95 to the actual demands of the user. [00034] The heat pump is a device constituted, according to one basic plan, by a closed circuit being coursed by a refrigerant fluid, and generally comprises a compressor, a condenser, an expansion valve, an evaporator and a cycle inversion valve, in order to allow switching over from the operation of heating an environment to that of cooling, and vice versa . [00035] Such equipment, through the refrigerant fluid, removes natural heat from the outside environment and, by compressing the refrigerant fluid in such a manner as to increase the temperature, releases the heat to the environment to be heated. The reversibility of the system allows, for example in the summer seasons, to use the heat pump in order to convey the heat present within dwellings to the outside, thus cooling the environments. [00036] In the plant 15 described, it is possible to use several types of heat pumps 100. [00037] For example an air-air heat pump, comprising the devices of the basic plan and at least two ventilators may be used for the treatment and/or conveyance of the internal air and the external air with respect to the environment to be conditioned. [00038] According to a further embodiment, an air-water heat pump is used, wherein, besides making the thermal cycle with the refrigerant fluid, water is drawn, for example from the mains supply, and is delivered there, after a heat exchange with the refrigerant fluid having taken place, in a series of pipes in order to accomplish the heat exchange with the environment to be conditioned. During the cooling or summer operation, the water is refrigerated, whilst during the heating operation, it is heated. The water may also be stored in a reservoir in such a manner as to increase the thermal inertia of the system.

[00039] According to a further embodiment, the air conditioning device 95 comprises a heat pump water heater, particularly adapted to the production of hot water for domestic requirements.

[00040] Within the heat pump water heater the refrigerant fluid, inside the evaporator removes heat from the outside environment, and then increases the temperature within the compressor, in such a manner as to release heat to the water to be heated, within the condenser.

[00041] The operation of a plant 15 according to the invention, will now be described.

[00042] Under conditions of sufficient solar radiation, the means of generating electrical energy 20 produce direct current electrical energy at a certain voltage and send it to the inverter device 40. The inverter device 40 transforms the direct current into alternating current at the desired frequency, for example 50 Hz in order to allow supplying the various electrical appliances 37 of the dwelling 10.

[00043] Through the primary circuit 45 the current is fed to the electrical control panel 50 having the function of switching it to the various electrical appliances 37 through the distribution grid 48.

[00044] Between the various appliances 37 at least one air conditioning device 95 is supplied comprising a converter device 110 in input which receives the alternating current and alters the frequency and/or the voltage on the basis of the load requested by the air conditioning device 95.

[00045] In other words, by altering the frequency and/or the voltage of the current it is possible to continuously alter the speed of the motor means of the heat pump 100, on the basis of the load requested for the conditioning of the dwelling 10.

[00046] From the primary circuit 45 originates a connection to the power mains 35 of the dwelling 10 comprising a counting meter 80 and a consumption meter 70. [00047] The power mains 35 is always able to distribute electrical energy to the electrical appliances 37 of the dwelling 10 if the energy requested by the appliances themselves exceeds the energy production of the means of generating electrical energy 20. [00048] In other words, the primary circuit 45 is able to draw electrical current directly from the power mains 35 in order to supply electrical appliances 37, when the production of electrical energy by the generating means 20 is less than the electrical energy requested by the electrical appliances 37.

[00049] Furthermore, the primary circuit 45 is able to feed the share of the electrical current produced by the generating means, in surplus to the immediate energy requirements of the electrical appliances 37, directly into the power mains 35 avoiding the accumulation of electrical energy within the primary circuit. If during the production of electrical energy by the generating means, no electrical appliance 37 requires energy for its operation, all the electrical energy produced by the generating means is directly fed into the power mains 35, thus avoiding the accumulation of electrical energy within the plant.

[00050] The plant does not envisage means for the accumulation of electrical energy, such as for example accumulator batteries, in that any electrical surplus produced is fed directly into the electrical grid and measured by the relevant counting meter.

[00051] During the daytime hours, and when solar radiation is sufficient, the appliances 37 are supplied with the electrical energy produced by the generating means 20, or by the solar panels and/or photovoltaic cells, and the supply from the power mains 35 is excluded.

[00052] When solar radiation is no longer sufficient, the supply is given by the power mains 35 which ensures the operation of the appliances. In this case the consumption meter 70 measures the consumption of current used from the power mains 35.

[00053] During the period of time in which solar radiation is present but the appliances 37 are not in operation, the electrical energy produced by the generating means 20 is fed into the power mains 35 and such energy is measured by the counting meter 80. [00054] Hence, when solar radiation is sufficient, the energy produced is alternatively used by the electrical appliances 37 or fed into the electricity grid 35. [00055] When solar radiation is not sufficient, and energy is required by the electrical appliances 37, this is supplied by the power mains 35.

[00056] The energy supplied by the user to the power mains 35 is measured by the counting meter 80 whilst the energy supplied by the power mains 35 to the user is measured by the consumption meter 70.

[00057] The plant 15 according to the invention is extremely advantageous for the user since, when the dwelling 10 is not occupied and the means of generating electrical energy 20 however produce energy, this energy is fed into the power mains 35 and the cost of such energy can be deducted from the consumption.

[00058] Above all, in dwellings occupied only for brief periods during the year, typically holiday homes, the plant, besides being advantageous from the environmental point of view, is economical for the user.

[00059] A holiday home is normally only occupied for a few days each year, during which the user can use both the energy produced by the generating means and, during the nighttime hours and during peaks in consumption, the energy from the power mains.

[00060] During all the days in which the dwelling 10 is not used, the means of generating electrical energy 20 will supply energy to the power mains 35. [00061] The described plant is particularly efficient in the production of electrical energy using alternative energy sources.

[00062] Furthermore, the described plant is particularly economical in the regulation of the air conditioning of the domestic environment.

[00063] Indeed, by altering the frequency and/or the voltage of the feed current of the air conditioning device 95, it is possible to continuously adjust the rotational speed of the compressor, modifying the load regimen. It is therefore possible to make the compressor operate at high power until the temperature of the environment reaches the desired value, and then to make the compressor operate at low power, i.e. at reduced speed, once the desired temperature is reached.

[00064] Furthermore, the described plant has a high energy output considering that it does not envisage the use of energy accumulation devices, such as for example reservoirs containing heated water or electrical energy accumulator batteries, which inevitably induce energetic losses, reducing the overall energy output of the plant. [00065] Indeed, the electrical energy produced by the means of generating electrical energy 20, when not required by the domestic appliances 37, or however in amounts which exceed the energy requirements of the domestic appliances 37, is directly fed into the power mains 35.

[00066] Furthermore, the described plant is particularly efficient in the management of the air conditioning of environments. Indeed, the plant combines the high efficiency of the energy generating means with the high efficiency of heat pump air conditioning devices, preferably regulated by a converter device. [00067] Heat pump devices are particularly convenient thanks to the fact that they exploit thermal energy, i.e. the natural heat removed from the outside environment. [00068] Furthermore, heat pump air conditioning devices, above all if regulated by a converter device, allow the achievement of the air conditioning of environments with low energy consumption.

[00069] In this manner, the energy generating means are able to produce electrical energy, in excess with respect to the requirements of the appliances, and to feed such surplus energy directly into the power mains. [00070] The synergic use of means of generating electrical energy and a heat pump allow the achievement of the air conditioning of environments with high outputs and with low energy consumption. The interaction of the system with the power mains 35 allows not only the making up for any possible shortages in electrical energy production by the generating means 20, but also to create electrical energy surplus to be fed directly into the power mains, avoiding the energy wastage connected with the use of accumulators or energy reservoirs. [00071] The illustrated example refers to a plant based on generating means constituted by solar panels and/or photovoltaic cells.

[00072] It is however obvious to the export in the art that the plant may comprise other types of renewable energy generating means such as, for example, wind energy generators .

[00073] It is in practice ascertained that the finding meets the pre-established task and aims.

[00074] A plant which allows the economically advantageous exploitation of renewable energy is indeed accomplished.

[00075] Naturally the materials used, as well as the dimensions, can be whatsoever according to the requirements and the state of the art.

Claims

1. A plant (15) adapted to interacting with a power mains (35) for the supply of electrical energy to electrical appliances (37), said plant (15) comprising

- a means of generating electrical energy (20) suited to producing electrical energy, exploiting renewable energy sources an electrical transformation means (33) adapted to receiving the electrical energy produced by said generating means (20) and to transforming it in such a manner as to make it suited to supplying said power mains

(35) and/or said electrical appliances (37)

- a primary circuit (45) electrically connected to said means of transformation (33) for receiving through these the electrical energy produced by the generating means

(20), wherein said primary circuit (45) is connected to at least one electrical appliance (37) through a distribution grid (48) and comprises an electrical bypass (55) connected to said power mains (35) , in such a manner as to allow said primary circuit (45) to draw electrical current directly from the power mains (35) in order to supply the electrical appliance (37), when the production of electrical energy by the generating means (20) is less than the electrical energy required by the electrical appliance (37) and in such a manner as to feed the share of electrical current, produced by the generating means (20) in excess of the present energy requirement of the electrical appliance (37), directly into the power mains (35) , thus avoiding the accumulation of electrical energy within the primary circuit (45) .

2. The plant (15) according to claim 1, wherein said means of generating electrical energy (20) comprises solar panels and/or photovoltaic cells.

3. The plant (15) according to any of the preceding claims, wherein said means of generating electrical energy (20) comprise wind generators.

4. The plant (15) according to any of the preceding claims, wherein the means of transformation (33), through said primary circuit, are electrically connected to an electrical control panel.

5. The plant (15) according to any of the preceding claims, wherein along said bypass (55) are inserted means for measuring electrical power (65), adapted to measuring both the flow of current flowing from the primary circuit

(45) towards the power mains (35) , and the flow of current flowing from the power mains (35) towards the primary circuit (45) .

6. The plant (15) according to claim 5, wherein said means of measuring electrical current (65) comprise a counting meter (80) and a consumption meter (70) connected in series to each other in such a manner as to have an inverted direction of measurement, the counting meter (80) being adapted to measuring the flow of current which passes from the primary circuit (45) towards the power mains (35) , and the power consumption meter (70) being adapted to measuring the flow of current which passes from the power mains (35) towards the primary circuit (45) .

7. The plant (15) according to claims 5 or 6, wherein said means of measuring electrical power (65) comprise a single meter, adapted to measuring the electrical power which flows from the power mains (35) towards the primary circuit (45) and vice versa .

8. The plant (15) according to any of the preceding claims, wherein said electrical appliances (37) comprise an air conditioning device (95) adapted to conditioning the environment served by the power mains (35) .

9. The plant (15) according to claim 8, wherein said air conditioning device (95) comprises a converter device

(110) adapted to receiving electrical energy from the electrical transformation means (33) and/or from the power mains (35) and of modifying the parameters of the electrical energy in output for the regulation of the operation of an air conditioning device (95).

10. The plant (15) according to claims 8 or 9, wherein said air conditioning device (95) comprises a heat pump (100) and a converter device (110) .

11. The plant (15) according to claims 9 or 10, wherein the converter device (110) receives as input from the distribution grid (48) an alternating current at a first frequency, or input frequency, and distributes as output an alternating current at a second frequency, or output frequency, which supplies motor means of the heat pump (100) .

12. The plant (15) according to claim 11, wherein said converter device (110) comprises a rectifying device (115) which receives the alternating current at the input frequency and rectifies it into direct current and an inverter (120) which transforms the direct current into alternating current at the desired output frequency, in such a manner as to regulate the operation of the motor means of the heat pump (100) .

13. The plant (15) according to claim 12, wherein said inverter (120) is adapted to altering the output voltage to be fed to the motor means of the heat pump (100) in such a manner as to modify the operation of the heat pump (100) .

14. The plant (15) according to any of the claims 8 to 13, wherein said air conditioning device (95) comprises a heat pump (100) of the air-air type.

15. The plant (15) according to any of the claims 8 to

14, wherein said air conditioning device (95) comprises a heat pump (100) of the air-water type.

16. The plant (15) according to any of the claims 8 to

15, wherein said air conditioning device (95) comprises a heat pump water heater.

17. A method for the production and the supply of electrical energy, comprising the stages of: providing a plant (15) according to any of the preceding claims, producing electrical energy through the means of generating electrical energy (20) , transforming, through electrical transformation means, the electrical energy produced by the generating means (20) in such a manner as to make it suitable to supplying a power mains (35) and/or electrical appliances (37), providing a primary circuit (45) electrically connected to electrical transformation means (33) and to a distribution grid (48) connected to at least one electrical appliance (37), providing, from said primary circuit (45), an electrical bypass (55) connected to said power mains (35) , in such a manner that when the production of electrical energy by the generating means (20) is less than the electrical energy requirements of the electrical appliance (37) the primary circuit (45) draws electrical energy directly from the power mains (35) and when the amount of electrical energy produced by the generating means (20) exceeds the energy requirements of the electrical appliances (37), the plant (15) feeds the excess electrical energy directly into the power mains

(35) , avoiding the accumulation of electrical energy within the plant (15) .

18. The method for the production and supply of electrical energy according to claim 17, comprising the stage of providing means for the measurement of electrical power (65) along said bypass (55) in such a manner that the electrical energy fed into the power mains (35) and the electrical energy drawn from the power mains (35) are measured by said means for the measurement of electrical power (65) .

19. The method for the production and supply of electrical energy according to claims 17 or 18, comprising the stage of using the electrical energy produced by the generating means (20) to supply an air conditioning device

(95) comprising a converter device (110) and a heat pump

(100) .

20. The method for the production and supply of electrical energy according to claim 19, comprising the stage of continuously regulating the operation of the air conditioning device (95) through said converter device (110) , limiting the energy requirement of the air conditioning device (95), in such a manner as to allow in the generating means (20) the production of a surplus of electrical energy to be fed directly into the power mains (35) .

21. A plant (15) for the exploitation of renewable energy sources in combination with traditional energy sources, particularly for the heating and cooling of dwellings (10), comprising means of generating renewable energy (20) suited to producing electrical energy which is fed into the domestic grid (45,48) for supplying various appliances (37), the plant (15) being characterised in comprising an inverter device (40) suited to feeding the electrical energy, produced by the generating means (20), into the power mains (35) of the dwelling (10) when the appliances do not require such electrical energy, the plant (15) additionally comprising at least one counting meter (80) suited to measuring the electrical energy produced by the generating means (20) and fed into the power mains (35) of the dwelling (10) .

22. The plant (15), according to claim 21, characterised in that the means of generating electrical energy (20) are constituted by solar panels and/or photovoltaic cells.

23. The plant (15), according to claims 21 or 22, characterised in that the means of generating electrical energy (20) are connected to an earth dissipater (30) and to an electrical control panel (50) through an inverter device (40) .

24. The plant (15), according to one or more of the claims 21 to 23, characterised in being connected to the power mains (35) of the dwelling (10) through a power consumption meter (70) and through a counting meter (80) .

25. The plant (15), according to one or more of the preceding claims, characterised in that said appliances

(37) comprise means of air conditioning (95) , light sources, domestic appliances.

26. The plant (15), according to one or more of the preceding claims, characterised in that the means of air conditioning (95) are characterised by hot and cold air conditioners with gas ecoinverters, or of another type.

27. The plant (15), according to one or more of the preceding claims, characterised in comprising one or more of the described and/or illustrated characteristics.