Device for collecting renewable energy

Abstract

The invention relates to a device (10) for collecting renewable energy sources, comprising photovoltaic modules (14.1, 14.2) and a support structure (12) for the photovoltaic modules (14.1, 14.2). The support structure (12) encloses a space (18) and, together with the photovoltaic modules (14.1, 14.2), forms an outer wall (16) of the enclosed space (18); the outer wall surface normal defined by the photovoltaic modules (14.1, 14.2) faces at least three different orientations. The photovoltaic modules (14.1, 14.2) are fastened to the support structure (12) in such a way that the rear faces of the photovoltaic modules (14.1, 14.2) facing the interior of the enclosed space (18) can be cooled by an air flow.

Description

[0001] The invention relates to a device for collecting renewable energy, in particular to a device for generating electricity using sunlight.

[0002] There are various forms of devices for collecting renewable energy in the prior art. Examples of devices for collecting renewable energy include wind power plants and photovoltaic power plants, but also solar thermal collectors for collecting heat using sunlight, or geothermal collectors for collecting heat from the ground.

[0003] Photovoltaic power plants usually comprise an array of photovoltaic modules, which in turn consist of solar cells. The surface formed by the solar cells in the photovoltaic modules is usually planar and surrounded by a frame. Photovoltaic modules are often installed on the roof of a house or on a rack structure of an open-air plant. For example, DE 20 2022 002 406 U1 discloses a greenhouse, the walls and / or roof of which are at least partially composed of a plate-shaped photovoltaic-thermal collector (PVT collector). The photovoltaic-thermal collector is a composite device consisting of a plate of light-transmitting material, solar cells and current-carrying ducts.

[0004] It is an object of the present invention to provide a device for collecting renewable energy, which is suitable for installation on a limited area.

[0005] To achieve the above object, the invention proposes a device for collecting renewable energy, which comprises photovoltaic modules and a support structure for the photovoltaic modules. The support structure surrounds a space and together with the photovoltaic modules forms at least six, preferably eight or more outer walls, which define a base contour of at least a hexagon, preferably an octagon or more. The surface normals defined by the photovoltaic modules on the outer walls are oriented towards at least six, preferably eight or more different directions, which are defined by the base contour of at least a hexagon, preferably an octagon or more. The angle difference between each adjacent direction is ideally the same, for example 36 degrees in a decagon structure, and the sum of the orientation angles of all photovoltaic modules is 360 degrees. In this respect, a spherical arrangement of the photovoltaic modules is optimal. In addition, the photovoltaic modules are fixed to the support structure in such a way that a ventilation space is left for the back of the photovoltaic modules facing the interior of the enclosed space, so that they can be cooled by air flow.

[0006] The photovoltaic modules are provided on all outer walls, i.e. they are provided omnidirectionally. Preferably, at least 80% of the area of each outer wall is composed of or covered by photovoltaic modules, i.e. all outer walls are preferably equipped with the same number of photovoltaic modules (of the same type). The latter is advantageous for achieving the desired goal of a nearly constant output power over several hours of the day.

[0007] In open photovoltaic installations, the photovoltaic modules can be optimally oriented towards the sun and, if necessary, also tracked, but when installed on a roof, the orientation of the photovoltaic modules is largely determined by the orientation of the respective roof surface or facade. The power production of a photovoltaic installation depends on a number of factors, among which the orientation of the photovoltaic modules. When all photovoltaic modules are oriented the same, only when the angle of the solar radiation with the normal to the surface of the photovoltaic modules is the smallest (i.e. only once a day), the photovoltaic modules can deliver the maximum electrical power.

[0008] However, with the device for collecting renewable energy according to the invention, the electrical power produced by the photovoltaic modules can remain nearly constant for several hours of the day, since the photovoltaic modules (more precisely, their surface normals) are oriented towards at least six different directions. Thus, during the day, the area of the device according to the invention that is directly illuminated by the sun remains nearly constant, since the outer walls of the device for collecting renewable energy according to the invention, together with the photovoltaic modules, form a polyhedral prism that approximates a cylindrical shape.

[0009] This is in sharp contrast to the conventional design philosophy, since the device for collecting renewable energy according to the invention also contains photovoltaic modules oriented towards the north, which are hardly directly illuminated by the sun and thus produce relatively little electrical power. However, it is precisely these photovoltaic modules that produce relatively little electrical power that enable the device for collecting renewable energy according to the invention to deliver a nearly constant power during most of the day, even though the direction of incidence of the solar rays and the solar altitude constantly change. The use of vertical outer walls, which is preferred, also contributes to this, since this orientation differs from the conventional preferred orientation of 35 degrees, so that the rays of the morning and evening, when the solar altitude is low, can be better exploited than at midday.

[0010] The all-around arrangement of the photovoltaic modules has the advantage that the area on which the sun is directly incident on the photovoltaic modules of the inventive device for collecting renewable energy remains almost constant over the course of the day, i.e. as the solar azimuth angle changes over time. The side walls composed of photovoltaic modules are arranged in a manner similar to a circular cylinder (e.g. hexagonal), while a roof structure composed of photovoltaic modules similar to a circular cone is arranged above the side walls (not extending to the sides of the side walls), by means of this combination, the total power output of the photovoltaic modules remains almost constant over the course of the day, even as the solar height changes over time. In the geographical latitudes of Central Europe, such as Germany, the north-facing photovoltaic modules receive direct sunlight only during the morning and evening hours in summer, but not at all in spring, autumn and winter. In typical Central European regions between 40 and 60 degrees of northern latitude, the annual sunshine duration is approximately 20 to 40 percent of the theoretical maximum of 4380 hours. 4380 hours is half of 8760 hours (total number of hours in a year), i.e. corresponds to the length of day and night, which means in turn that 60 to 80 percent of the time in a year the sky is cloudy. Due to absorption and reflection by the atmosphere, and the resulting atmospheric radiation (emission), the atmosphere itself becomes a radiation source. This radiation is also referred to as diffuse radiation, which is mainly isotropic, i.e. directionless, in cloudy weather, i.e. the entire hemisphere (half of the sphere) is radiating. All photovoltaic modules receive this diffuse radiation equally, so even in winter, photovoltaic modules facing away from the sun can make the same power contribution as those facing south. The sum of direct and diffuse radiation is the total radiation, and it is precisely by virtue of the all-around module orientation that the inventive device for collecting renewable energy makes maximum use of the total radiation, thus achieving the maximum possible annual power generation (the entire hemisphere emits diffuse radiation). The position of the sun in the course of the day is reflected in two parameters for the utilization of direct solar radiation: the solar azimuth angle (azimuth direction) and the solar elevation angle (at noon at the zenith). By means of the photovoltaic module arrangement geometry described in the invention, a constant area of direct irradiation can be maintained throughout the day on sunny, sunny days. Therefore, the photovoltaic power remains almost constant over the course of the day, and in the summer solstice in Europe, 16 to 18 hours of direct utilization per day can be achieved.

[0011] The almost constant output power over as long a period of the day as possible makes it possible to use the output power more efficiently, since all electrical consumers and inverters do not have to be designed for the total peak power of all photovoltaic modules, but only for the total power of the inventive device for collecting renewable energy. This total power is produced by a number of photovoltaic modules with non-optimal orientation and remains relatively constant over several hours of the day.

[0012] Other advantages that result from this include, for example, a higher direct use rate of the generated power, since the required power is supplied for a longer period of time during the day. For example, if the generated power is used to run an electrolyzer, the electrolyzer is in full load for a longer period of time, i.e. is operated at maximum rated power for a longer period of time. As a result, there is no need for a large amount of grid feed-in or energy storage, since the surplus power generated during peak times is reduced and the required power is supplied and utilized for a longer period of time during the day.

[0013] One advantageous result is that the inverters or DC transformers only need to be designed for a maximum of 40% of the peak power of the photovoltaic modules. Therefore, a preferred device for collecting renewable energy comprises one or more inverters, which are electrically connected to the photovoltaic modules, and all inverters are designed such that their electrical power is less than 50% of the total peak electrical power of all photovoltaic modules.

[0014] Due to the use of diffuse radiation, the amount of generated power of the device according to the invention is even significantly higher than that of a photovoltaic power plant with tracking photovoltaic modules ("trackers") of the same area. This is because the total area of the photovoltaic modules in the device for collecting renewable energy according to the invention is larger than in a photovoltaic power plant with tracking photovoltaic modules. In a photovoltaic power plant with tracking photovoltaic modules, the arrangement of the photovoltaic modules must avoid mutual shading, so that a horizontal spacing between the modules must be maintained. The annual amount of generated power of the device for collecting renewable energy according to the invention can even be more than twice that of a photovoltaic power plant with tracking photovoltaic modules, since the latter cannot make efficient use of diffuse radiation due to the smaller effective photovoltaic module area, whereas the device according to the invention can make full use of diffuse radiation.

[0015] This is possible because in the device for collecting renewable energy according to the invention, the total light-receiving area (i.e. the radiation-receiving area) of all photovoltaic modules is about 4 to 5 times larger relative to the area of the device.

[0016] Therefore, the device for collecting renewable energy according to the invention has two main advantages over conventional photovoltaic power plants: First, the amount of generated power per unit of area (based on the area of the device according to the invention) is significantly higher. Second, on sunny days, the amount of generated power during the day is very stable, i.e. the output power is smooth.

[0017] In order to achieve such a stable power curve, it is particularly advantageous if the side walls of the support structure are arranged perpendicularly and at least approximately form a cylinder, and if the roof structure, which is preferably provided with photovoltaic modules, forms a circular cone or a circular truncated cone with a cross section that is approximately circular. If an opening for the installation of a wind turbine is provided at the top of the circular cone, the power curve of the total power output during the day can be "adjusted" to be more constant by adjusting the angle of inclination of the photovoltaic modules at the top of the circular cone, i.e. the roof structure, so that a nearly constant power output is achieved.

[0018] According to the application, the support structure and the photovoltaic modules together form at least six, preferably eight or more, outer walls, which define a base contour of the enclosed space that is at least hexagonal, preferably octagonal or more polygonal. The base contour is preferably a regular polygon, so that a shape close to a cylinder is achieved.

[0019] The ratio of the height of the outer walls (not including the roof structure, which is preferably provided with inclined photovoltaic modules) to the diameter of the base contour is preferably between 0.75 and 1.25. This ratio, in particular in combination with the roof structure provided with photovoltaic modules, is particularly advantageous because it achieves the desired effect of a nearly constant power output over several hours during the day. This is because the photovoltaic modules on the roof structure can compensate for a drop in the power output of the other photovoltaic modules at midday in summer, when the sun is very high.

[0020] Preferably, the outer walls that define the base contour of the enclosed space are arranged perpendicularly, are rectangular and adjoin one another.

[0021] According to one embodiment, the base contour defined by the outer walls has a maximum outer diameter of less than 5 m, preferably less than 4 m.

[0022] The support structure preferably comprises a roof structure, which carries photovoltaic modules arranged at an inclination, which face in different directions.

[0023] In a particularly preferred embodiment, the device comprises an air source heat pump, which is supplied with air that flows along the inner side of the photovoltaic modules, cools the photovoltaic modules and is thus preheated. In such a device, the air source heat pump can be operated with a particularly high coefficient of performance (COP), so that relatively more heat can be generated from the electrical energy consumed to drive the heat pump. For example, the thermal power output of the air source heat pump can be 4 to 5 times the electrical power required to drive the heat pump. "Air source heat pump" in this context means all heat pumps that use air as a heat source, including various types of air source heat pumps, such as integrated and split heat pumps.

[0024] The outer wall is preferably provided with air guiding structures (e.g. air flow channels) for ventilating the back of the photovoltaic module. These air guiding structures are arranged and configured such that air flows against the natural convection direction along the back of the photovoltaic module and is directed towards the air source heat pump.

[0025] The flow of air against the natural convection direction is preferably driven by a fan or blower of the air source heat pump.

[0026] Considering that the cooling effect increases the efficiency of the photovoltaic module, the following conclusions can be drawn:

[0027] The additional power generated by cooling the photovoltaic module exceeds the energy consumption of the fan required for the operation of the heat pump (e.g. 1.2 kWh) and also the energy consumption for a cooling operation only (reduced fan speed) (e.g. 0.5 kWh). However, a greater benefit is achieved by the additional thermal energy, which can be used in summer by the heat pump for heating domestic hot water. This additional thermal energy reduces the electrical energy required to drive the heat pump in the case of constant thermal demand. This additional thermal energy is derived from the air that is preheated after cooling the photovoltaic module. The annual power generation of a photovoltaic module using the cooling according to the application is typically increased by 5% to 10% compared to a photovoltaic module system without cooling using ambient air. The electrical energy consumption of the fan required for the forced air flow is preferably adjusted by speed control and adjusted to the cooling effect, unless the heat pump currently has a higher demand for heating (e.g. for heating domestic hot water).

[0028] As an example, a multi-family house with 48 residential units has a daily average thermal demand for domestic hot water in summer of approximately 550 kWh (thermal energy unit). To provide this thermal energy with a COP of 4, 137.5 kWh of electrical energy is consumed. By additionally using the waste heat of the photovoltaic module, the COP can be increased on average to approximately 5. In this case, only 110 kWh of electrical energy is required to meet the thermal demand for domestic hot water. This value is approximately equivalent to the daily power generation of the device for collecting renewable energy according to the application.

[0029] Overall, the COP can be increased by at least 1.0 per year and even by 1.3 in winter. Thus, the annual performance factor of the heat pump in the device for collecting renewable energy according to the application can reach the level of a ground source heat pump.

[0030] Preferably, the air source heat pump is electrically connected to the photovoltaic module in order to be operated using the electrical current generated thereby. Since the COP of the air source heat pump is particularly high in the above-described arrangement, the device is able to provide heat very efficiently.

[0031] According to another embodiment, a gas storage device, i.e. a normal pressure hydrogen or oxygen storage device, is provided inside the space enclosed by the outer wall. In this embodiment, the device preferably comprises an electrolyser for generating hydrogen using the electrical energy generated by the photovoltaic and storing the hydrogen in the gas storage device. This device enables the use of the electrical energy generated by the photovoltaic even if the electrical energy is not immediately used. Furthermore, during periods when the photovoltaic is not able to generate sufficient electrical energy, e.g. during winter, the stored hydrogen can be used to generate electrical energy by means of a fuel cell and supply electrical power.

[0032] It is particularly advantageous that the device for collecting renewable energy according to the application enables a nearly constant electrical power output over several hours of the day for the operation of the electrolyser. When the device for collecting renewable energy according to the application is used in combination with an electrolyser, the power requirement of the electrolyser can be designed to match the nearly constant electrical power output of the device over several hours of the day, so that the electrolyser is operated under optimum conditions. In this way, the full load operating time of the electrolyser can be approximately 3000 hours per year, whereas the full load operating time of a conventional photovoltaic device in combination with an electrolyser is only approximately 1000 hours per year.

[0033] Another advantageous aspect is that the air used for cooling the photovoltaic modules flows along the inner side of the photovoltaic modules, at the same time ventilating the normal pressure hydrogen storage device. This ventilation increases the operating safety of the normal pressure hydrogen storage device, since even in the event of a hydrogen leak, the leaked hydrogen is necessarily diluted to a large extent and is easily detectable, so that no danger arises.

[0034] The device comprising a support structure of the type described above, photovoltaic modules fixed to the support structure, a gas storage device and an electrolyser, constitutes an independent inventive concept in itself, which can be implemented independently of the other aspects described herein, such as the air cooling of the photovoltaic modules.

[0035] On the basis of this independent inventive concept, a device for collecting renewable energy is proposed, which comprises photovoltaic modules and a support structure for the photovoltaic modules. The support structure encloses a space and forms, together with the photovoltaic modules, an outer wall of the enclosed space, the outer wall surface normal defined by the photovoltaic modules pointing in at least three different directions. Inside the enclosed space, a gas storage device is provided, and the device further comprises an electrolyser, which is electrically connected to the photovoltaic modules in order to be operated using the electrical current generated by the photovoltaic modules and to generate hydrogen during operation. The gas storage device is preferably enclosed by a flexible, gas-tight outer shell in a balloon-like structure, so that it has a variable internal volume, which is completely filled with hydrogen or oxygen during operation.

[0036] If three identical devices according to the invention for collecting renewable energy are installed at the same site, it is advantageous from the point of view of efficiency and service life to equip two of the devices with hydrogen storage and one device with oxygen storage. In this way, the fuel cell can be operated with pure oxygen when generating electricity (electricity recovery), which is more efficient and gentler and has a longer service life than when using ambient air, which can contain pollutants such as carbon monoxide, sulfur dioxide or other active harmful gases that damage the catalyst. Preferably, the device that contains both at least one hydrogen storage and at least one oxygen storage should be equipped with an electrolyzer that can produce both hydrogen and oxygen at the same time. When water is electrolyzed, two volumes of hydrogen (H2) and one volume of oxygen (O2) are produced. Therefore, the volume of the hydrogen storage is preferably twice the volume of the oxygen storage. To achieve this, three identical devices according to the invention for collecting renewable energy can be installed at the same site, two of which are equipped with hydrogen storage and one of which is equipped with oxygen storage.

[0037] In another embodiment, the device comprises a wind turbine having a mast that passes through the center of the space enclosed by the outer wall. The mast of the wind turbine is preferably a telescopic mast, by means of which the wind turbine can be selectively brought into a retracted state, in which the wind turbine is located inside the space enclosed by the outer wall, if necessary also including the roof structure, and an extended state, in which the wind turbine is located outside the space enclosed by the outer wall, if necessary also including the roof structure.

[0038] The invention will be further illustrated by means of examples, with reference to the accompanying drawings. The drawings comprise:

[0039] Figure 1 a: side view of a device according to the invention for collecting renewable energy with an extended wind turbine;

[0040] Figure 1 b: side view of a device according to the invention for collecting renewable energy with a retracted wind turbine;

[0041] Figure 1 c: Figure 1 a and Figure 1 b: perspective view of a device according to the invention for collecting renewable energy;

[0042] Figure 2 a: side view of another device according to the invention for collecting renewable energy;

[0043] Figure 2 b: Figure 2 a: top view of a device according to the invention for collecting renewable energy;

[0044] Figure 2 c: Figure 2 a and Figure 2 b show a perspective view of a device for collecting renewable energy according to the invention;

[0045] Figure 3 a to Figure 3 d: diagram showing the variation of the power production on different sunny days;

[0046] Figure 4 : Figure 3 d: enlarged view of the diagram;

[0047] Figure 5 : perspective view of a device for collecting renewable energy according to the invention;

[0048] Figure 6 : perspective view of another device for collecting renewable energy according to the invention;

[0049] Figure 7 a, Figure 7 b: two side views of a device for collecting renewable energy according to the invention corresponding Figure 1 a and Figure 1 b;

[0050] Figure 8 a, Figure 8 b: two perspective views of a system comprising a wind turbine and a photovoltaic power generation device;

[0051] Figure 9 : schematic view of a device for collecting renewable energy according to the invention, provided with a wind guide structure for the ventilation and air cooling of the back of the photovoltaic modules and a heat pump, the air cooled by the photovoltaic modules being preheated by the wind guide structure being fed to the heat pump;

[0052] Figure 10 a, Figure 10 b: two schematic views for illustrating the way in which the ventilation of the photovoltaic modules is combined with an air source heat pump;

[0053] Figure 11 a, Figure 11 b: two further schematic views for illustrating the way in which the back of the photovoltaic modules is ventilated;

[0054] Figure 12 a, Figure 12 b: two side views of two different devices for collecting renewable energy according to the invention, integrated with a gas storage device.

[0055] The device 10 for collecting renewable energy according to the invention has support structures 12, on which photovoltaic modules 14 are fixed. The support structures 12 with the photovoltaic modules 14.1 form outer walls 16, which enclose a space 18. The outer walls 16 are arranged vertically and define a polygonal floor contour. In the embodiment shown in Figure 1 a、 Figure 1 b、 Figure 1 c and Figure 2 a、 Figure 2 b、 Figure 2 c, ten mutually adjoining vertical outer walls 16 are provided, which together define a decagonal floor contour. Each outer wall 16 is formed by a corresponding support structure 12 and two photovoltaic modules 14 arranged one above the other. In addition, the support structures 12 form a roof structure 20, which carries five photovoltaic modules 14.2 arranged obliquely. The support structures 12, including the roof structure 20 and the photovoltaic modules fixed to the support structures 12 and the roof structure 20, enclose the space 18 in such a way that, according to a preferred embodiment, an air source heat pump 22 can be arranged in the enclosed space 18. The number of photovoltaic modules 14 shown in the example is merely exemplary and depends on the size of the device and / or the spatial requirements of the installation site.

[0056] In order to achieve a maximum power output with less fluctuation in the amount of electricity generated over a number of hours during the day (see also Figure 3 a to Figure 3 d and Figure 4 , it is advantageous if the side walls with the photovoltaic modules 14.1 form a right prism, i.e. a straight prism with a regular polygonal floor. However, if photovoltaic modules 14.1 are arranged only on the side walls of such a prism, the amount of electricity generated will decrease significantly at midday, when the sun is very high. Therefore, it is preferred to arrange oblique photovoltaic modules 14.2 on the top of the prism. The angle of inclination of the oblique photovoltaic modules 14.2 to the vertical is preferably between 30° and 60°.

[0057] The height of the side walls, i.e. the outer walls 16, is preferably approximately equal to the diameter of the floor contour, for example 0.75 to 1.25 times the diameter of the floor contour.

[0058] In addition, a wind turbine 26 Figure 1 a、 Figure 1 b) or 26' Figure 2 a、 Figure 2b) of the column 24 or 24'. The wind generator 26 or 26' is fixed to the column 24 or 24' in such a way that it is movable up and down along the column 24 or 24' so as to be able to assume a retracted position and an extended position. To this end, the column 24 or 24' can be a telescopic column. In the retracted position, the wind generator 26 or 26' is located within the enclosed space 18; in the extended position, the wind generator 26 or 26' is located above the roof structure 20. As Figure 1 a, Figure 1 b, Figure 1 c and Figure 2 a, Figure 2 b, Figure 2 c, the roof structure 20 encloses a central opening 28 through which the wind generator 26 or 26' can pass in and out. Figure 7 a shows the wind generator 26 in the extended state, Figure 7 b shows the wind generator 26 in the retracted state.

[0059] Figure 5 The device 10 for collecting renewable energy according to the application is shown, in which the roof structure 20 of the support structure 12 carries five tilted photovoltaic modules 14.2, which enclose a central opening 28 through which the wind generator 26 or 26' can pass in and out.

[0060] If no wind generator is provided, a roof structure 20' can also be provided, which does not enclose a central opening, but is composed, for example, of six photovoltaic modules 14.2, as Figure 6 is shown.

[0061] As is shown in particular in Figure 2 a, the floor profile defined by the outer wall 16 is such that the outer surface of the photovoltaic modules 14.1 is directed almost towards all azimuths. The decagonal floor profile approximates a circular shape. The photovoltaic modules 14.1 are directed towards all azimuths, so that the electric power generated by the photovoltaic modules does not only assume a narrow peak at midday, but remains almost constantly high over a plurality of hours, for example eight hours. This is shown in Figure 3 a to Figure 3 d and Figure 4 e. The lower curve shows a typical curve of the electric power generated over the course of a day, when all photovoltaic modules are directed southwards (in the example, tilted by 35°). In this case, the maximum power occurs at midday. Due to the constantly changing angle of incidence of the sun over the course of a day, the electric power generated by photovoltaic modules directed in this way also varies over the course of a day.

[0062] In the present invention, the photovoltaic modules are arranged along a near-circular base profile (more precisely, a regular polygonal base profile) on the vertical side walls, in combination with the inclined photovoltaic modules 14.2 on the roof structure 20, so that different photovoltaic modules will output their respective maximum power at different time periods as the angle of incidence of the sun changes throughout the day. This results in a nearly constant power output over a plurality of hours, as shown in the graphs of Figure 3 a to Figure 3 d and Figure 4 e, which show a nearly constant power output over a plurality of hours.

[0063] The number of photovoltaic modules 14.1 on the side walls 16 and 14.2 on the roof structure 20 also depends on the size of the device 10 for collecting renewable energy. Typical sizes are as follows:

[0064] - base profile diameter 3.5 meters; installed capacity of the photovoltaic modules 14.1 and 14.2 is approximately 10 kilowatt peak (kWp), which can output approximately 4 kilowatts of electrical power for a significant period of time during a sunny day;

[0065] - base profile diameter 11.5 meters; installed capacity of the photovoltaic modules 14.1 and 14.2 is approximately 97.5 kilowatt peak (kWp), which can output approximately 40 kilowatts of electrical power for a significant period of time during a sunny day;

[0066] - base profile diameter 35 meters; installed capacity of the photovoltaic modules 14.1 and 14.2 is approximately 1100 kilowatt peak (kWp), which can output approximately 440 kilowatts of electrical power for a significant period of time during a sunny day; see also Figure 12 a and Figure 12 b, which show a device with a gas storage device for storing hydrogen produced by electrolysis during the sun season.

[0067] Ideally, the device for collecting renewable energy of the present invention is connected to at least one electrical consumer whose power consumption matches the electrical power output by the device 10 for collecting renewable energy. In this way, the full-load utilization time of the renewable energy (solar energy) throughout the year can be increased by more than 15% compared to ground-mounted photovoltaic modules or roof-tilt-mounted photovoltaic power plants, during the period when the sun is above the equator (between March 21 and September 23).

[0068] The use of telescopic wind turbines 26 or 26' with telescopic columns 24 or 24' also helps to increase the annual power production of the device 10 above that of a single-sided ground-mounted photovoltaic module. Wind turbines typically produce more energy in the winter months than in the summer months with abundant sunshine. Therefore, the combination of photovoltaic modules and air / water heat pumps allows for a significant increase in the full-load utilization time of solar and wind energy.

[0069] Another device 10' for harvesting renewable energy comprises a wind turbine 26"' having a fixed tower 24"' around which a support structure 12' is arranged, on which support structure 12' photovoltaic modules 14 are fixed, which structure is similar to the one shown in Figure 1 and Figure 2 for harvesting renewable energy 10; see Figure 8 a and Figure 8 b. In the shown embodiment, the vertical side walls 16 forming a cylinder can accommodate about 2000 photovoltaic modules, and the roof structure forming a truncated cone can accommodate about 754 photovoltaic modules, which roof structure encloses an opening through which the tower 24"' of the wind turbine 26"' passes. As will be explained below, the support structure 12' with the fixed photovoltaic modules 14 also encloses an inner space 18 here, which can be used for storing gaseous hydrogen or the like.

[0070] Another aspect of the device 10 is shown in Figure 9 , Figure 10 and Figure 11 . These figures show that on the inner side of the outer wall 16, i.e. on the back of the photovoltaic modules 14.1 and 14.2, a ventilation structure is provided for cooling the photovoltaic modules 14.1 and 14.2. To achieve ventilation, a back plate 30 is preferably provided at a location that is favorable for the flow of air, between which back plate 30 and the back of the photovoltaic modules 14.1 and 14.2 an air flow channel 32 is formed. This air flow channel can be fluidly connected to the heat pump 22. In this way, the heat pump 22 can be operated with preheated air, thereby increasing the coefficient of performance (COP) of the heat pump 22. The heat pump is preferably designed as a unitary or split device. At the same time, the efficiency of the photovoltaic modules 14.1 and 14.2 can be prevented from decreasing due to an increase in temperature. To enable a better transfer of heat from the back of the photovoltaic modules 14.1 and 14.2 to the air flowing through it, wind guiding elements are preferably provided in the air flow channel 32, which elements cause the air flowing through it to become turbulent, i.e. to swirl. This increases the convective heat transfer coefficient between the photovoltaic modules 14.1, 14.2 and the air flowing through it.

[0071] The air source heat pump 22 comprises a heat exchanger 22.1 and a fan 22.2.

[0072] By providing a back plate 30 on the back of the photovoltaic modules 14.1 and 14.2, a controllable back ventilation of the photovoltaic modules is achieved. This increases the electrical efficiency of the photovoltaic modules under constant diffuse and direct radiation, because the photovoltaic modules 14.1 and 14.2 have a positive temperature coefficient (PTC) characteristic, i.e. the lower the temperature, the smaller the internal resistance. Depending on the specific application scenario, the back plate 30 can also be designed to have thermal insulation properties.

[0073] In addition, the air is heated by the heat exchange.

[0074] If a heat pump 22 with an outdoor unit is installed and the outdoor unit uses ambient air as the main heat source, the air can be preheated on the back of the photovoltaic modules 14.1 and 14.2 before entering the evaporator of the heat pump. In this way, the efficiency of the heat pump 22 can be improved in the presence of sunlight. The operating time can thus be shortened and energy can be saved.

[0075] The air cooling the back of the photovoltaic modules is sucked from above to below against the natural convection direction. For this purpose, air flow guides (e.g. air flow channels) are provided on the back of the photovoltaic modules 14.1 and 14.2, along which the air flows over the back of the photovoltaic modules 14.1 and 14.2. The air flow guides can be formed, for example, by the back sheet 30.

[0076] The additional power generated by cooling the photovoltaic modules 14.1 and 14.2 exceeds the energy consumption of the fan 22.2 required for the operation of the heat pump (e.g. 1.2 kWh) and also the energy consumption in the cooling mode alone (e.g. 0.5 kWh). However, the greater benefit is the additional thermal energy, which can be used in the summer by the heat pump 22 for heating domestic hot water. This additional thermal energy reduces the electrical energy required to drive the heat pump in the case of constant thermal demand. This additional thermal energy is derived from the air preheated after cooling the photovoltaic modules 14.1 and 14.2.

[0077] As an example as described above, a multi-family house with 48 residential units has a daily average thermal demand for domestic hot water in the summer of approximately 550 kWh (thermal energy unit). To provide this thermal energy with a COP of 4, 137.5 kWh of electrical energy is consumed. By additionally using the waste heat of the photovoltaic modules, the COP can be increased on average to approximately 5. In this case, only 110 kWh of electrical energy is required to meet the thermal demand for domestic hot water. This value is approximately equivalent to the daily power generation of the inventive device for collecting renewable energy.

[0078] Overall, the COP can be increased by at least 1.0 per year and by 1.3 in winter. Thus, the annual performance factor of the heat pump in the inventive device for collecting renewable energy can reach the level of a ground source heat pump.

[0079] Depending on the specific application scenario, the photovoltaic modules 14.1 and 14.2 can also be cooled by a fan or a blower 34, but in this case the electrical energy consumption of the fan or blower should be less than the additional power generated by the cooling.

[0080] The interior space 18 has various uses. In small devices, this space can for example be used as a storage room for garden tools, bicycles or similar items. For a monolithic heat pump, the generated heat is transported to the building via well-insulated pipes, usually laid underground. For well-insulated buildings, for example buildings that receive a lot of solar radiation heat through south-facing windows, it is recommended to use an intermediate heat storage in the form of a thermal store in order to store the solar thermal energy converted from electricity for the night or the next day. If it is not possible to install a thermal store inside the building, a thermal store can be installed in the interior space 18.

[0081] The interior space 18 of a large device has a larger volume. When both the diameter and the height are doubled, the volume increases by a factor of three. This volume is therefore very suitable for storing solar and wind energy, which fluctuate greatly. The large volume is particularly suitable for hydrogen storage, since hydrogen has a low density at normal pressure.

[0082] Inside the interior space 18, a gas storage device 36 can also be provided for storing hydrogen or oxygen, etc., see Figure 12 a and Figure 12 b. The gas storage device 36 is preferably a normal-pressure gas storage device. For smaller interior spaces 18, the gas storage device 36 can be a small-volume balloon, see Figure 8 b. For larger storage volumes, the gas storage device 36 can be provided with a rolling membrane, on top of which a counterweight is loaded (see Figure 8 a), similar to the structure in a gas meter. Depending on the specific design, such a storage device can also withstand a slight overpressure, but the maximum overpressure is not more than 50 mbar. Other possible design forms of the gas storage device 36 include a telescopic gas cylinder, a bell jar gas cylinder, a wet gas cylinder, a disc gas cylinder, a spiral gas cylinder and a spherical gas cylinder.

[0083] The rolling membrane 38 or the balloon shell 38' is preferably made of a gas-tight, flexible material web or film.

[0084] In order to produce hydrogen from the electrical energy generated by the photovoltaic modules 14.1 and 14.2, the device 10 is equipped with an electrolyzer 40. This electrolyzer is electrically connected to the photovoltaic modules 14.1 and 14.2 at least indirectly, for example via corresponding inverter electronics or an inverter. In addition, the electrolyzer is connected via a gas line (not shown) to the interior of the gas storage device 36 in order to store the hydrogen produced by the electrolyzer 40 in the gas storage device 36. The gas storage device 36 can also be connected via another gas line (also not shown) to other devices, for example to a fuel cell or a gas water heater, to which the hydrogen stored in the gas storage device 36 is to be supplied (usually these devices are not a direct component of the device 10).

[0085] Since the gas storage device 36 is a constant pressure storage device, the hydrogen produced by the electrolyser 40 can be directly filled into the gas storage device 36 without compression. By planning the design and operating time of the electrolyser 40, the hydrogen production and thus the filling speed of the gas storage device 36 can be directly set. There is no need for a compressor, as no compressor is needed.

[0086] Figure 8 a and Figure 8 b can also be provided with a constant pressure gas storage device, as shown in the examples in Figure 12 a and Figure 12 b. By using solar and / or wind energy, hydrogen can be produced and stored at constant pressure.

[0087] During periods without sunlight and without wind ("dark calm periods"), the stored hydrogen can be converted into electrical energy by means of a fuel cell, which can then be fed into the public grid, the industrial grid or into an electric car charging station via a local wind transformer, for use as 100% renewable energy generated electrical energy, for example for (direct current) charging.

[0088] Preferably, such a device for collecting renewable energy is connected to one or more fuel cells, which are preferably provided in a heating station, which can provide heat to a building. In this way, not only can hydrogen be converted into electrical energy by means of a fuel cell, but also the generated heat energy can be used.

[0089] List of reference signs

[0090] 10, 10' device for collecting renewable energy

[0091] 12, 12' support structure

[0092] 14.1, 14.2 photovoltaic module

[0093] 16 wall, side wall

[0094] 18 enclosed space, interior space

[0095] 20, 20' roof structure

[0096] 22 air source heat pump

[0097] 22.1 heat exchanger of the air source heat pump

[0098] 22.2 fan of the air source heat pump

[0099] 24, 24"' column, tower, telescopic column of the wind turbine

[0100] 26, 26', 26"' wind turbine / wind wheel

[0101] 28 opening in roof structure

[0102] 30 back plate

[0103] 32 air flow passage

[0104] 34 blower, fan

[0105] 36 constant pressure gas storage device

[0106] 38 air tight material web, air tight enclosure

[0107] 38' balloon enclosure

[0108] 40 electrolyzer

Claims

1. An apparatus (10) for collecting renewable energy, the apparatus comprising photovoltaic modules (14.1, 14.2) and a support structure (12) for the photovoltaic modules (14.1, 14.2), wherein the photovoltaic modules (14.1, 14.2) are fixed to the support structure (12) such that the photovoltaic modules (14.1, 14.2) are cooled by airflow on their back surfaces facing the interior of the enclosed space (18), wherein, The support structure (12) surrounds a space (18) and together with the photovoltaic modules (14.1, 14.2) forms the outer wall (16) of the surrounded space (18), characterized in that the support structure (12) and the photovoltaic modules (14.1, 14.2) together form at least six, preferably eight or more outer walls (16), which define at least a hexagonal, preferably octagonal or more polygonal bottom profile of the surrounded space (18), wherein the surface normal defined by the photovoltaic modules (14.1, 14.2) on the outer wall is oriented in at least six, preferably eight or more different orientations, which are defined by the hexagonal, preferably octagonal or more polygonal bottom profile.

2. The apparatus according to claim 1, characterized in that, The supporting structure (12) includes a roof structure (20) that carries inclined photovoltaic modules (14.2) facing different directions.

3. The apparatus according to claim 1 or 2, characterized in that, The outer walls (16) defining the bottom contour of the enclosed space (18) are vertically arranged, adjacent to each other, and are all rectangular.

4. The apparatus according to at least one of claims 1 to 3, characterized in that, The bottom contour formed by the outer wall (16) is a regular polygon.

5. The apparatus according to at least one of claims 1 to 4, characterized in that, The ratio of the height of the outer wall (16) to the diameter of the bottom profile is between 0.75 and 1.

25.

6. The apparatus according to at least one of claims 1 to 5, characterized in that, The device includes one or more inverters electrically connected to the photovoltaic modules, and the inverters are designed to have a power output of less than 50% of the total peak power output of all photovoltaic modules.

7. The apparatus according to at least one of claims 1 to 6, characterized in that, An atmospheric pressure hydrogen storage device is provided inside the space (18) surrounded by the outer wall (16).

8. The apparatus according to at least one of claims 1 to 7, characterized in that, The device (10) includes a wind turbine (26) having a column (24) that passes through the center of a space (18) surrounded by the outer wall (16).

9. The apparatus according to claim 8, characterized in that, The column (24) of the wind turbine (26) is a telescopic column, by means of which the wind turbine (26) can selectively be in a retracted state and an extended state. In the retracted state, the wind turbine (26) is located inside the space (18) surrounded by the outer wall (16) and, if necessary, the roof structure (20). In the extended state, the wind turbine (26) is located outside the space (18) surrounded by the outer wall (16) and, if necessary, the roof structure (20).

10. The apparatus according to at least one of claims 1 to 9, characterized in that, The device (10) includes an air source heat pump (22) that is supplied with air that flows along the inside of the photovoltaic module (14.1), cools the photovoltaic module (14.1), and is thus preheated during operation.

11. The apparatus according to claim 10, characterized in that, The air source heat pump (22) is electrically connected to the photovoltaic modules (14.1, 14.2) such that the air source heat pump (22) operates using the current generated by the photovoltaic modules (14.1, 14.2).

12. The apparatus according to at least one of claims 10 or 11, characterized in that, The outer wall is provided with an air guide structure for ventilating the back of the photovoltaic module. The air guide structure is arranged and configured such that air flows against the natural convection direction along the back of the photovoltaic module and is guided to the air source heat pump.

13. The apparatus according to at least one of claims 10 or 12, characterized in that, The airflow against the natural convection direction is caused by the fan of the air source heat pump.

14. A device (10) for collecting renewable energy, the device comprising photovoltaic modules (14.1, 14.2) and a support structure (12) for the photovoltaic modules (14.1, 14.2), characterized in that, The support structure (12) surrounds a space (18) and together with the photovoltaic modules (14.1, 14.2) forms the outer wall (16) of the surrounded space (18). The surface normal of the outer wall defined by the photovoltaic modules (14.1, 14.2) is oriented in at least three different directions. An atmospheric pressure hydrogen storage device (36) is provided in the surrounded space (18), and the device (10) includes an electrolyzer (40) electrically connected to the photovoltaic modules (14.1, 14.2) such that the electrolyzer (40) operates using the current generated by the photovoltaic modules (14.1, 14.2) and generates hydrogen during operation.

15. The apparatus according to claim 14, characterized in that, The atmospheric pressure hydrogen storage device (36) is surrounded by a flexible, airtight shell (38) in a balloon-like structure and has a variable internal volume that is completely filled with hydrogen during operation.

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