DE102008008652A1 - Thermal electrical accumulator for use in solar thermal plants for wash water heating and heating backup, comprises heat reservoir and cold reservoir, which are thermally separated, and arrangement of thermoelectric generators are provided - Google Patents

Abstract

The thermoelectric accumulator comprises a heat reservoir and a cold reservoir, which are thermally separated, and an arrangement of thermoelectric generators. Thermoelectric generators are interposed on transition points of heat pipes of a vacuum tube collector. A heat exchanger is provided for a collector circuit for recovering electrical energy. Thermal energy is supplied in selected temperatures such that a thermoelectric battery drive is obtained on the basis of thermal storage having different temperature levels without heat supply and without cooling.

Description

Of the Thermoelectric accumulator is both a procedure as well a new application for the use of conventional solar thermal systems the for heating domestic water and or heating support of buildings are provided to also gain electrical energy using thermoelectric Generators based on the thermoelectric effect Seebeck, can generate electrical energy. To the impression contains the patent application two devices. A system which in the simplest case from two heat storage tanks and an array of thermoelectric elements is, according to the schematic diagram from a conventional one Solar collector system for heat storage provided mass (marked as warm side in the drawing), Heat supplied. At night Previous solar collector systems are usually not active or it is known that in some cases oversized solar thermal systems, to protect against summer overheating, with a cooling device on provided the basis of an outdoor air heat exchanger are preferred to cool at night when needed by the system. at This method will be day / night temperature differences in the Outside air, reinforced by heat from solar insolation gains offset in time to generate electrical Energy using thermoelectric elements is used unless cooling already by Nutzwärmeentnahme z. B. has been sufficient for heating purposes of the building. This is a continuous operation or the maintenance of a constant Temperature difference for the energetic feeding of an arrangement of thermoelectric Aimed at generators. This is preferred during the day by a solar thermal Plant gained heat stored as well as cold at night from the outside air which occurs especially in the second half of the night saved. For cost reasons is used in this procedure for nocturnal cooling preferably the same solar collector used as during the day provided it is a type which is suitable for heat exchange with the outside air has.

The effectiveness of the thermoelectric accumulator, or as one might call it, of the thermoelectric battery, in contrast to generator systems, does not result from peaks in solar radiation occurring only a few hours a day, or nocturnal cold, whose peak values last only a few hours and are usually in the second half of the night occur but, from a continuous operation to the photovoltaic according to the current state of the art is not capable unless it is z. B. at night artificially supplied with light energy. Also, the photovoltaic is far less suitable thermal losses from electrical energy, z. B. to be used for heating purposes of a building. The comparison with the photovoltaic is justified both because the photovoltaic is intended to convert solar radiation into electrical energy as well as because both technologies or generators work without any moving parts apart from circulating pumps which are not part of the thermoelectric generators but in most Cases increase the efficiency of the solar thermal system if necessary heat or cold over fluid circulation * 13 ) is supplied to the generators and this is not already sufficiently thermogravitatorisch driven.

The Dimensioning of photovoltaic systems is based on peak values Solar radiation due to technical inability Light energy without conversion for a later one Use to save or without major losses to convert again. Losses (thermal losses are difficult to use) usable Temperatures z. B .. reduce for heating purposes of a building the efficiency. In contrast, the efficiency of thermoelectric increases Generators in the temperature range which allows from the losses of Generators in direct form (isobaric) to extract usable heat. Heat off Solar thermal systems is easy to store. Appropriate Devices are widely used. In summer, thermoelectric generators achieve high electrical efficiencies during the efficiency of Photovoltaic decreases with increasing temperature. The design of a thermoelectric battery oriented in its simplest form on average daily values of solar irradiation as well as mean values night Outside air temperature. In contrast, the design is oriented photovoltaic plants necessarily at peak solar Irradiation or to a generator operation which relies on it is the peak solar radiation directly into electrical To transform energy.

ever after dimensioning of both the solar thermal system as the thermoelectric accumulator itself, can seasonal temperature changes the outside air complements through seasonal solar irradiation gains to the electric Energy generation can be used. In a special way cost-effective if z. B. a conventional Flat collector alternately as an absorber of solar radiation and as a heat exchanger with the nightly or winter outside air is used depending on the dimensions of the overall system as well as climatic conditions.

In its simplest embodiment, a thermoelectric accumulator corresponds to the example application with two heat accumulators * 9 ) and * 10 ). The branching of the Enthalpieströmmung from the Sun larkollektor * 6 ) to the heat storage * 9 ) or cold storage * 10 ) or another cooling unit if available * 4 ) to the cold storage, or to neither of the two memories or the stopping / starting of the circulating pump (s) if any, takes place time and or temperature. Time-controlled as long as you know that from certain times of the day the sun is low enough so that the system can be switched to cooling mode. Temperature-controlled depending on the temperature of Enthalpieströmmung and the storage masses z. B. decided whether the flow is suitable for cooling the cold side or for heating the hot side or for neither of the two purposes.

Of the thermoelectric accumulator in its simplest form, has weaknesses the be improved or remedied by an extension of the procedure. This includes that ever according to current temperatures of the warm side and the cold side, lying in between Temperatures of enthalpy not used from the solar collector or an additional cooling unit can be since they neither warming the warm side still for cooling the cold side are suitable.

The mentioned weaknesses is achieved by an extension of the method of the thermoelectric battery encountered.

The Warm side (hot cell) and the cold side (cold cell) get one defined upper and lower temperature setpoint range. The lower Temperature setpoint range (cold cell), is provided to heat up low temperature level from the continuous enthalpy flow supplied to the system changing Temperature, to save. This becomes the source of electrical energy used or for cooling the arrangement of thermoelectric generators.

The temperature range zwichen the setpoints of the warm and the cold cell, is divided according to a number of heat storage, each of which a different setpoint temperature range is assigned. The temperatures of these middle areas are much more frequent in the enthalpy growth of a solar collector than the peak values. The simple accumulator can not use much of this energy depending on the temperature condition of the two storage masses, although the temperature of the enthalpy flow is useful e.g. B. for heating support or for domestic water heating. No matter what temperature the enthalpy flow just has. At another time, this heat or cold is usable and is therefore fed to storage unless the corresponding memory have already reached their upper temperature limit. The system is also intended to generate electrical energy. This z. B. by heat exchange zwichen the warm and the cold cell, temperature conditions occur, in which the hot cell has a temperature below its target value and the cold cell above. Depending on the use, the methereological changes as well as the dimensioning or the condition of the system, such deviations from the nominal values already occur in a short-term manner. The method provides in such cases, the adjacent heat storage moderate mean temperatures, but statistically considered to occur considerably more frequently, to warm up the hot cell * 9 ) or for cooling the cold cell * 10 ). High efficiencies result from the common use for electrical energy production and useful heat extraction, preferably from the cold cell, if necessary from the adjacent stores the next higher temperature levels * 27 ) respectively. * 28 ). The task of the warm cell * 9 ) and the cold cell * 10 ) is statically defined in the system. They have the same objects as in the system according to claim 1 to 5. Claim 6 is an extension of the method according to claim 1 for improving the thermal and thermoelectric efficiency of the thermoelectric battery. The thermoelectric battery operation is based on a temperature difference zwichen the designated areas of an array of thermoelectric generators, which is maintained by supplying heat from the hot cell and by cold supply from the cold cell ( * 9 ) * 10 )). Due to the Seebeck effect (TJ Seebeck 1822), an electrical voltage is generated. The thermoelectric accumulator is discharged when the temperatures of the hot cell and the cold cell have become equal.

Electric accumulator charging:

Of the Although accumulator is not intended, but it is possible under Utilization of the reversal effect "Peltier effect" (J. C. A. Peltier 1834), as well as in the Peltier modules resulting Joule heat, the Charge accumulator electrically.

energetically much more useful is the thermal charge with a solar collector / air heat exchanger.

Thermal accumulator charging (preferred):

Basically, the accumulator is indifferent to the heat or cold source with which it is charged. However, it is conceived to heat from the environment in particular reinforced with a solar air collector, graded into different temperature levels in the respective accumulator cells to produce with the temperature differences electrical power and or z. B. for air conditioning purposes of a house as a heat storage or stand by cold storage. Winter cold is just as useful for the function of the accumulator as summer heat if the system has been dimensioned accordingly. As an alternative to other possibilities, the example of heat transfer to the cells and between the cells via heatpipes / evaporators is shown in the example (see schematic diagram) * 21 ) to * 26 ) realized. The number of cells is variable. The number in the schematic diagram is based on commercially available heat pipe boiling points, which are often offered in increments of 20 ° C, and on the desire to cover a temperature range up to 90 ° C. The unwanted heat conduction through the heat pipes in the non-active state is low. Preferred are low thermal conductivity plastics, preferably thermal contact over copper, and preferred as the fluid, alcohols of various boiling points.

Of the Accumulator is provided with the help of a Enthalpieströmmung changing regularly Temperature as you in the fluid circuit between solar panels and heat storage happens to be loaded.

In the order will be first Cells with a high setpoint temperature level supplied with heat. The progressively cooled in this process fluid supplied in succession, more cells lower setpoint temperature levels with heat. The geometry the supply path is preferably to be dimensioned, the one suitable flow rate arises.

Of the Accumulator can be both thermal (preferred) as well as electric to be charged. The accumulator can after appropriate charging electrical Generate electricity. But you can already during the thermal charging process generate electricity. One of the functional principles of the thermoelectric accumulator, no matter what temperature Collector / air heat exchanger currently available represents, this sorted by target temperature ranges the corresponding accumulator cells supply. Correspondingly, the cells or storage masses are dimensioned according to the stadistisch expected frequency. Duration with the corresponding temperatures in the enthalpy of a Solar collector and the available enthalpy.

The contained in the thermoelectric accumulator according to the principle diagram Logic that substitutes for other techniques do accomplish this first part of the task with the help of purely temperature-driven physical processes, the one temperature-controlled electrical control of the heat supply superfluous. Essential here are evaporation temperature of various substances (preferably alcohols), evaporation energy, condensation energy, Pressure Verhältnise, capillarity, Gravity, geometry, etc. Standard heatpipes / evaporators, have the ability using mentioned physical processes, a very high heat transfer between a mass with temperature above its boiling point and a mass with temperature below your boiling point. Relatively small are the unavoidable transmission heat losses which are related to this.

the Accumulator supplied Heat becomes sequential cooled. This is first heat energy delivered to cells with high set temperatures, the set temperature range below the temperature level of the supplied heat and the upper temperature setpoint not yet reached. These are heatpipes / evaporator with on arranged the desired temperature range tuned boiling point.

The Enthalpieströmmung has in this sequential isobaric cooling process depending on the state of charge of the accumulator continuously cooled by heat pipes / evaporator the heat in cells that do not yet transport their upper setpoint temperature achieved. On the way back to the collector, the heat energy supply channel is circled on the upper side the accumulator cells. Therefore on the upper side, because the processes in Heatpipes / evaporator, have to do with gravity and in a vertical arrangement a higher Have efficiency or because they are in the upper part for cooling the cold side associated accumulator cells are used, the have warmed up in the course of electrical battery operation.

Power generation operation:

in the Fully charged state are the temperatures of the battery cells within its setpoint range. The two have lines with the designation warm cell and cold cell respectively the largest and lowest temperature. The arrangement of thermoelectric generators which is preferably arranged thermally parallel and electrically serially are generate a DC electrical voltage due to the Seebeck effect. The heat supply from the hot cell in connection with the cold supply from the cold cell keep the temperature difference between the surfaces of the Peltier modules upright and thus the electrical voltage. An external electric energy Consumer can be supplied with electrical energy. there creates an accelerated heat flow through the Peltier modules. The resulting cooling of the hot cell and heating the Cold cell can with the extended accumulator in a first step lead to it that the temperature the hot cell falls below the temperature of the adjacent cell.

With Help appropriately selected Evaporator starts a heat transfer the same thing happens automatically when falling below the Target temperature of the next Row. The same thing happens on the cold side. The temperature of the warmed Cold cell exceeds the temperature of the neighboring cell. The suitably selected evaporator begin automatically with a heat transfer to cooler Neighboring cell. The temperatures of the individual cells change while power generation in the way described until you approximate or have adjusted and no further electrical energy possible is.

in the Upper area are all the cold side associated accumulator cells cooled, if you have exceeded the upper temperature setpoint. Eg in the In the case of reinforced concrete, it makes sense to use this upper limit expand regarding the information in the schematic diagram.

It applies, the contents of the Heatpipes / evaporator is evaporated in total and not capable of further condensation / evaporation cycles heat transport to afford, or liquefied in total and also not capable of heat transport to afford or only the unwanted heat transfer through transmission. The technique shown in the schematic diagram for illustrative purposes, is based on a regulatory logic that exemplifies by example technically with the help of different evaporation temperatures of corresponding heat pipes / evaporator was shown. she stands substituting for an electronic temperature-controlled control, at the z. B .. in conjunction with in the z. B. reinforced concrete cells Heat exchange piping such as B. in a floor or wall heating usual, controlled by the controller unit, e.g. B. electromechanically controlled a concrete cell heat supplied becomes.

The required auxiliary electrical energy of such a management as well as the susceptibility in terms of technical faults, Auxiliary energy for Circulation etc. stands for simplicity, freedom from maintenance, self-control etc. of the system chosen for the purpose of Of course, one too Self-discharge property by minimizable but unavoidable Thermal bridges of Heatpipes or evaporator.

The Fluid masses that have to be moved around one Supply circuit of the extended accumulator as described to suffice, has of course u. a. with the geometry of the cooling fins, the flow rate etc. to do. Peltier modules currently have an efficiency far below the photovoltaic of about ~ only * 5% (under favorable circumstances until to 8%) in terms of sea bucket effect.

Of the ~ 10% to 15% efficiency usually in buildings installed polycrystalline photovoltaic, (decreasing with increasing Temperature of the generators) is more modern compared to an efficiency Absorber of solar collectors of up to 95% less thermal losses depending on the collector type used. One of the current state of Peltier module development (occasionally also called Seebeck modules) of ~ 5 to 8% electric energy production less 1% auxiliary power can be a competition to the photovoltaic. Also due to the continuous load in conjunction with a thermoelectric Battery possible is as well as the possibility possibly exploiting thermal losses for use in the building in favor of the solar collector in conjunction with a thermoelectric Battery runs out. Also because of the accumulator in connection with a solar collector at the same time in some climatic areas or depending on the collector area etc. is capable of heating a house almost 100% tig with to provide renewable energy. The electrical energy production only insignificantly reduces the heat available Energy in the system.

in the Summer are many solar thermal plants from an overheating problem are affected and are emptied due to explosion hazard or out of operation taken. The energy supply from nature is not used.

Explanations to the drawings.

• *1 ) Raising the temperature level of the hot side, by means of technical equipment, a planned for thermoelectric battery operation mass preferred by using a solar thermal system.
• * 2 ) Heat energy supply to increase the temperature of one or more provided for the thermoelectric battery operation of the hot side masses preferably with a solar thermal system.
• * 3 ) Lowering the temperature level by means of technical equipment, preferably with suitable also for cooling solar thermal systems, a provided for the thermoelectric battery operation mass.
• * 4 ) Cooler for mass lower temperature levels if required. z. B. by nocturnal operation of the same solar collector, which has provided in daytime operation of the mass higher temperature levels or the warm side, heat available.
• * 5 ) Additional cooling of the mass lower temperature levels in the summer or when useful heat removal z. B. by Heizbrauchwasserentnahme from the mass lower temperature levels is insufficient.
• * 6 ) Heat supply substitute for forward and reverse in the case of a fluid.
• * 7 ) Substituting for forward and reverse in the case of a fluid.
• *8th ) Thermoelectric element or arrangement of thermoelectric elements, which can generate electricity based on the thermoelectric effect Seebeck (TJ Seebeck, 1822) or can be used for charging the accumulator using the inverse effect Peltier (JCA Peltier, 1834).
• * 9 ) Heat storage mass with higher temperature when accumulator is charged. (Hot cell)
• * 10 ) Mass of lower temperature when battery is charged. (Cold cell)
• * 11 ) Heat exchanger hot side.
• * 12 ) Heat exchanger cold side.
• * 13 ) The circulation serves to increase the efficiency. Preferred embodiment with thermo-gravitationally driven circulation with or without the assistance of circulating pumps. In the case of z. As a metal as a heat conductor (preferably copper), high efficiencies are possible depending on the geometry without circulation.
• * 14 ) Preferred embodiment of the hot side: heat storage mass which is preferably fed by the solar collector circuit with heat. The hot side should be equipped with a heat exchange device that allows it to be fed with heat from another heat source in winter, if required.
• * 15 ) Preferred embodiment of the cold side: It is generally known that under summer climatic conditions, with normal sized solar collector systems, a summer overheating problem can be present. At night also in the summer z. B. the outside air more suitable temperatures than during the day to solve the problem by cooling the system to be used with technical tools. The thermoelectric accumulator, can also usually diverge significantly in the summer, so at a time in the energy supply and demand, use this previously lost thermal energy to generate electrical energy. This can be done either by using a cold reserve from the night or depending on the design of the system from the winter. The greatest energy efficiency results when the cold side is used for domestic hot water preparation or when useful heat extraction takes place from the cold side. Only when the temperature of the hot side is not sufficiently high to useful heat z. B. to provide domestic hot water, the hot side is used. For example, a mixer tap, can be used to the required domestic hot water temperature by adding a portion of the hot side. Under German climatic conditions, nocturnal cooling is typically energetically appropriate only in summer. In spring and autumn, with normal-sized solar collector systems, the supply of thermal energy is about equal to the demand. Usually in the summer, an energetic situation may arise in which the solar thermal system suffers from overheating because the Nutzwärmeantnahme is not sufficient to cool the cold side sufficiently. As shown in the graphic part of the example, a summer cooling is required in such cases, preferably at night under German climatic conditions, especially in summer, at night more suitable for outdoor air temperatures are cool to energy-efficient cool the cold side with the help of the outside air. Depending on the dimensions of the system is also a cold reserve z. B. from the winter time possible which is used in times of overheating for cooling. To save costs, can be used in times of overheating, as nocturnal cooling device of the same solar collector which during the day with the help of solar heat radiation, the warm side has supplied heat, if the solar collector type has a suitability to z. B. nocturnal to be used for cooling the cold side, results in a particularly economical embodiment of the system as shown in the example. The energetically most sensible cooling of the system results when the cold side is at the same time useful heat supplier.
• * 16 ) Optional locking device for interrupting the heat transfer on the hot side.
• * 17 ) Optional locking device for interrupting the heat transfer on the cold side. Of importance when charging the accumulator by supplying electrical power is desired (not recommended). In the locked state, the Joule heat is increasingly used to heat the hot side. After the heat pump effect of the Peltier modules is no longer sufficient to further increase the temperature difference, the valve is locked and increases the current
• * 18 ) Insulation. Z. B Vakuumdämmpaneele
• * 19 ) U = f (T1 - T2) (Kelvin relation). Electrical voltage caused by Seebeck effect due to a temperature difference (T1 - T2) which is exposed to the arrangement of thermoelectric generators.
• * 20 ) Time and / or temperature-controlled switching to cooling or night mode. In the case of a circulating fluid to increase the heat transfer, ivm two circulation pumps, the switching by switching off the circulation pump which is responsible for the heat transfer to the mass higher temperature and switching on a circulation pump which triggers the cooling operation of the cold side. Also, a single circulation pump can be used in conjunction with temperature or time-controlled valves.
• * 21 ) Arrangement of heatpipes or evaporators with boiling points 30 ° C and 50 ° C
• * 22 ) Arrangement of heatpipes or evaporators with boiling points 50 ° C and 70 ° C
• * 23 ) Arrangement of heatpipes or evaporators with boiling points 70 ° C and 90 ° C
• * 24 ) Arrangement of heatpipes or evaporators with boiling points 15 ° C and 30 ° C
• * 25 ) Arrangement of heatpipes or evaporators with boiling points 30 ° C, 50 ° C and 70 ° C
• * 26 ) Arrangement of heatpipes or evaporator with boiling point 30 ° C
• * 27 ) Heat storage is provided to store heat in the temperature range 30 ° C to 50 ° C.
• * 28 ) Heat storage is provided to store heat in the temperature range 50 ° C to 70 ° C.
• * 29 ) Fluid circulation with regularly changing temperature. Alternatively, a heat transfer via a solid body is possible.
• * 30 ) The mass of the lowest setpoint temperature as well as the mass of the highest setpoint temperature are led in this example to avoid circulation until the arrangement of thermoelectric generators. A circulation is not provided in this example.

Claims (7)

In buildings, Solar thermal systems for domestic water heating and or for heating support used. It is known that experiments guided where were thermoelectric generators at the crossing points the heatpipes of a vacuum tube collector and the heat exchanger were switched to the collector circuit to electrical energy to win. It is also known that the Brenkammer a Peletheizung thermoelectric generators were installed for the same purpose. These systems are generators where heat transfer points with a high temperature gradient be used with a small number of thermoelectric generators to achieve the same electrical work as with the same heat flow due a correspondingly higher Number of thermally parallel connected thermoelectric generators but lower temperature difference. It is not known that solar thermal Plants used in buildings be in an accumulator consisting of at least one heat storage, a cold storage, each thermally separated, as well as an arrangement thermoelectric Generators, thermal energy is supplied to temperature-selective, so that over one Period, without heat and without cooling a thermoelectric battery operation due to thermal storage with different temperature levels is enabled. Thermoelectric accumulator according to claim 1 also characterized in that it allows solar collector types also for heat exchange with the outside air are suitable for. B. flat panels as usual during the day as Collector as well as in times of summer overheating, at night as a cooling unit for the cold storage to use without the Generator operation must come to a standstill. Thermoelectric accumulator according to claim 1 also characterized in that useful heat removal from the cold side z. B. by domestic hot water or heating support, for Charging the accumulator contributes. A additional cooling is at normal solar thermal systems in buildings only required in summer. The method of the thermoelectric accumulator allows high efficiencies provided that the losses from the thermoelectric battery operation, which fed to the storage were, z. B. in the building used for heating support become. Thermoelectric accumulator according to claim 1 also characterized in that the previously unused thermal energy in times of summer overheating, in solar thermal systems in the domestic sector, for electrical Energy recovery uses if the cold side is cooled z. B. according to claim Second Thermoelectric accumulator according to claim 1 also characterized in that regularly in time offset peaks of solar radiation and low points the outside air temperature z. B. of a solar thermal system in the form of an enthalpy with continuously changing Temperature provided be energy-efficient if the collector surface, the Storage masses, the area or number of thermoelectric generators dimensioned accordingly or were dimensioned to a very uniform continuous operation of the arrangement thermoelectric generators lead or a permanent load Strommerzeugung. This property has various possitive effects further use in both the required conversion processes before being fed into the grid or used elsewhere. In its simplest embodiment, a thermoelectric accumulator corresponds to claim 1. The branching of enthalpy from the solar collector to the heat storage or cold storage or other cooling unit if available to the cold storage, or to neither of the two stores or stopping the circulation pump (s) if available , time and or temperature-controlled. Time-controlled as long as you know that from certain times of the day the sun's position is so low, that the system can be switched to cooling mode. Temperature-controlled depending on the temperature of Enthalpieströmmung and the storage masses z. B. decided whether the flow is suitable for cooling the cold side or for heating the hot side or for neither of the two purposes. The thermoelectric accumulator in its simplest form, has weaknesses which are improved or eliminated by an extension of the process. This includes that depending on the current temperatures of the hot side and the cold side, Zwzwichen lying Enthalpieströmmung from the solar collector or an additional cooling unit can not be used as they are neither suitable for heating the hot side nor for cooling the cold side. The mentioned weaknesses are countered by an extension of the method of the thermoelectric accumulator. The hot side (hot cell) and the cold side (cold cell) receive a defined upper and lower temperature setpoint range. The lower temperature set point range (cold cell) is designed to store heat at a low temperature level from the continuous-temperature enthalpy flow supplied to the system. This is used for electrical energy extraction or for cooling the arrangement of thermoelectric generators. The temperature range zwichen the setpoints of the warm and the cold cell, is divided according to a number of heat storage, each of which a different setpoint temperature range is assigned. The temperatures of these middle areas are much more frequent in the enthalpy growth of a solar collector than the peak values. The system according to claim 1 to 5 can not use a large part of this energy depending on the temperature state of the two storage masses although the temperature levels are suitable for Nutzwärmeentnahme or for domestic water heating. The system is also intended to generate electrical energy. This z. B. heat exchange zwichen the warm and the cold cell, temperature conditions occur in which the hot cell has a temperature below its target value and the Klatzelle above. Depending on the use, the methereological changes as well as the dimensioning or the condition of the system, such deviations from the nominal values already occur in a short-term manner. The method provides in such cases, the adjacent heat storage medium desired temperatures, but which occur much more common, to be used for heating the hot cell or for cooling the cold cell. High efficiencies result from the common use for electrical energy production and useful heat extraction, preferably from the cold cell, if necessary from the adjacent stores the next higher temperature levels. The task of the hot cell and the cold cell is determined statically in the system. They have the same objects as in the system according to claim 1 to 5. Claim 6 is an extension of the method according to claim 1 for improving the thermal and thermoelectric efficiency of the thermoelectric battery. It is not known that in particular flat plate collectors at night as a cooler be kept in operation for the purpose of generating electrical Energy.