PHOTOVOLTAIC ROOF AND ATMOSPHERIC WATER GENERATOR

Abstract

A roof (Figure 1: 4) which is covered with a photovoltaic surface (Figure 1: 2) delimits a space (Figure 1: 3) in which a large volume of an adsorbent / desorbent (Figure 1: 9) of water vapor is dispersed. In this space (Figure 1: 2) a circulation of ambient air (Figure 1: 5N) at night (Figure 1: N) is cool and charges said adsorbent with humidity (Figure 1: 9), then a circulation of ambient air (Figure 1: 5J) during the day (Figure 1: J) is heated in contact with the lower part of the photovoltaic surface (Figure 1: 2) which is exposed to solar radiation (Figure 1: 12) and is charged with humidity (Figure 1: 14) in contact with the adsorbent / desorbent (Figure 1: 9).An atmospheric water generator (Figure 1: 10) condenses water vapor from the outgoing air flow (Figure 1: 7J) that has been humidified by its passage through the space (Figure 1: 3) formed by the roof (Figure 1: 4) and the photovoltaic surface (Figure 1: 2), and produces an increased volume of water compared to its usual operation without this humidification device (Figure 1: 1). Figure for Abstract: [Fig.1].

Description

Title of the invention: PHOTOVOLTAIC ROOF AND ATMOSPHERIC WATER GENERATOR Technical field of the invention

[0001] The invention relates to photovoltaic roofs and atmospheric water generators. Technical background

[0002] Photovoltaic roofs are roofs on which photovoltaic solar panels have been installed. The panels then take on a slope and an orientation which are those of the roof. In general, the photovoltaic panels are slightly spaced from each other in order to allow a flow of ambient air to pass under the panels, which reduces the temperature rise of the panels. In fact, the panels are generally black in color, which has the effect of absorbing part of the solar radiation and transforming it into thermal energy; the rise in the temperature of the cells would then reduce their performance.

[0003] When the solar panels are placed on the ground, it is known and advisable to orient and tilt the photovoltaic panels in a certain way relative to the horizontal in order to produce on average over a year a maximum of kWh of electricity; this electrical production being proportional to the useful surface area of ​​said panels. For this, it is necessary to space the panels from each other sufficiently so that they do not cast shadows on each other regardless of the position of the sun during the year and regardless of the time of day. The useful surface area of ​​the solar panels is then less than the total surface area of ​​the land on which the panels are installed, but they individually produce a maximum of electrical energy depending on the latitude and climatic characteristics of the location. This observation is also valid for the installation of solar panels on flat and horizontal roofs.A choice must then be made between a maximum of photovoltaic surfaces installed horizontally or a smaller useful surface area of ​​solar panels but well oriented. The difference in production between these two choices can be up to 60% more production for panels installed horizontally and over the entire available surface. This surplus production is at the expense of the cost price of the kilowatt-hour (kWh) produced, since this surplus production will have required a surplus of poorly oriented (horizontal) photovoltaic surfaces and therefore less efficient. Choosing the option of maximum electricity production with regard to the available installation surface and with a higher cost price of the kWh produced (such as for example the total surface area of ​​a roof. flat and horizontal with solar panels positioned horizontally), is generally done when the need for electricity is a priority to the detriment of its cost. This is particularly the case for electrical applications in isolated sites, therefore outside a public distribution network, and when the surface area for installing the panels is small, particularly when it is a roof of a building or industrial premises. When this need for electricity is a priority compared to its production cost, it is because at least one application is powered by the solar panels and this application is itself a priority, whether in an economic, health, or ecological context. Presentation of the invention

[0004] The aim of the invention is to describe a photovoltaic roof which supplies electricity to an atmospheric water generator and which increases the water production performance of said generator. To increase the performance of said photovoltaic water generator, it is then judicious to choose a total photovoltaic surface on the roof rather than choosing an arrangement of solar panels which are inclined and separated from each other.

[0005] Indeed, the production of atmospheric and photovoltaic water can be a priority necessity which requires a maximum of solar electricity production (therefore a maximum useful surface area of ​​solar panels). The invention then describes a means of increasing the performance of said atmospheric water generator. Summary of the invention

[0006] In its basic version the device ([Fig.l]: 1) object of the invention is a roof ([Fig.l]: 4) photovoltaic ([Fig.l]: 2), horizontal or at any angle of inclination, which generates atmospheric water ([Fig.l]: 11) and which comprises:

[0007] - a roof ([Fig.l]: 4) of a building, house, hangar, or more generally any type of covering covering a construction ([Fig.l]: 14) supported by a frame.

[0008] - photovoltaic solar panels ([Fig.l]: 2) positioned above said roof ([Fig.l]: 4) and arranged so as to form an airtight photovoltaic surface ([Fig.l]: 2); the photovoltaic surface ([Fig.l]: 2) being able to cover all or part of said roof ([Fig.l]: 4).

[0009] - a space ([Fig.l]: 3) formed between said roof ([Fig.l]: 4) and said surface photovoltaic ([Fig.l]: 2), this space ([Fig.l]: 3) being able to be crossed by an air flow ([Fig.l]: 14) coming from the outside ([Fig.l]: 5N at night and 5J during the day) by means of incoming openings ([Fig.l]: 15), outgoing openings ([Fig.l]: 13) and fans ([Fig.l]: 6 and 8).

[0010] - an atmospheric water generator (10) which sucks in the outgoing air flow ([Fig.l]: 7N at night or 7J during the day) of said space ([Fig.l]: 3) and which extracts (at least in part) its water ([Fig.l]: 11),

[0011] characterized in that said space ([Fig.l]: 3) contains an adsorbent / desorbent ([Fig.l]: 9) effective for retaining atmospheric water vapor at ambient temperature and restoring it at a higher temperature, so that at night ([Fig.l]: N) an incoming fresh air flow ([Fig.l]: 5N) passes through said space ([Fig.l]: 3) and charges the adsorbent ([Fig.l]: 9) with humidity, and that during the day (J) an incoming outside air flow ([Fig.l]: 5J), less cool than that at night, passes through said space (3) and is heated in contact with the lower part of the photovoltaic surface ([Fig.l]: 2) which is heated by solar radiation ([Fig.l]: 12), so that said heated air flow ([Fig.l]: 14) charges itself with the humidity of the adsorbent / desorbent ([Fig.l]: 9) then comes out ([Fig.l]: 7J) through the outgoing opening ([Fig.l]: 13) and feeds said atmospheric water generator ([Fig.l]: 10).

[0012] The advantage of this device ([Fig.l]: 1) of roof ([Fig.l]: 4) photovoltaic ([Fig.l]: 2) and atmospheric water generator ([Fig.l]: 11) is that it allows both:

[0013] - to produce a maximum of solar electricity due to a photovoltaic surface ([Fig.l]: 2) significant compared to the surface area of ​​said roof ([Fig.l]: 4); said roof ([Fig.l]: 4) being able to be covered ([Fig.l]: 2) in its entirety.

[0014] - the photovoltaic surface ([Fig.l]: 2) being airtight, it allows on the one hand significant resistance to strong winds and easy recovery of rainwater.

[0015] - the ventilation ([Fig.l]: 6 and 8) of the space ([Fig.l]: 3) between the roof ([Fig.l]: 4) and the photovoltaic surface ([Fig.l]: 2) creates a cooling of the said roof ([Fig.l]: 4) during periods of high heat; this cooling having a positive impact on the cooling of the interior of the building ([Fig.l]: 14).

[0016] - the adsorbent ([Fig.l]: 9) plays a role in regulating the temperature of said roof ([Fig.l]: 4). Indeed, the said adsorbent can be in itself a good thermal insulator like silica gel which has the same insulating properties as glass. And on the other hand, the said adsorbent ([Fig.l]: 9) on the one hand sees its temperature increase during its adsorption phase, that is to say during periods of low outside air temperature ([Fig.l]: 5N and mainly at night N) and on the other hand sees its temperature decrease during its desorption phase, that is to say during periods of high outside air temperature ([Fig.l]: 5 J and mainly on day J).

[0017] - the atmospheric water generator ([Fig.l]: 10) receives the air during the day ([Fig.l]: 7J) which has been moistened in contact with the adsorbent ([Fig.l]: 9), which allows said generator ([Fig.l]: 10) to condense more water ([Fig.l]: 11) with the same expenditure of electrical energy. The average water production can thus be doubled.

[0018] - local production of atmospheric water ([Fig. 1]: 11), at the construction level ([Fig.l]: 14), allows easy watering of vegetated surfaces arranged on the facades or on part of the roof ([Fig.l]: 4).

[0019] - the adsorbent ([Fig.l]: 9) which plays a major role in the effectiveness of the device ([Fig.l]: 1) can have a relatively low purchase cost when purchased in large quantities. Indeed, in the example of silica gel (silica oxide) used in the form of balls 2 to 5 mm in diameter, placing a layer one centimeter thick on the surface of said roof ([Fig.l]: 4) would only require a weight of approximately 8 kg of silica gel per square meter of surface, i.e. a cost of less than 10 euros.

[0020] In additional embodiments, said roofing device ([Fig.l]: 1) ([Fig.l]: 4) comprises a photovoltaic surface ([Fig.l]: 2) which is flat, curved or contains inclined planes, transparent or semi-transparent parts, or rainwater recovery devices. Indeed, as the photovoltaic surface ([Fig.l]: 2) is airtight, it is also watertight; which allows rain to flow towards storage tanks

[0021] In an improved embodiment, said roofing device ([Fig.l]: 1) ([Fig.l]: 4) according to the invention uses as adsorbent / desorbent ([Fig.l]: 9) of water vapor effective materials chosen from the following list: organometallic frameworks, covalent organic frameworks, zeolitic imidazole frameworks, metal catecholates, metal azolates, zeolites, carbon, charcoal, porous rocks, silica, silica oxide, porous polymers, porous organic polymers, microporous polymers, polymers, crosslinked polymers, salts, metal oxides, porous cages, clathrates, monoliths, organic molecules, lamellae, metals, metalloids, or combinations thereof,

[0022] In another improved embodiment, said device ([Fig.l]: 1) of roof ([Fig.l]: 4) according to the invention, the adsorbent / desorbent ([Fig.l]: 9) is distributed in a thin layer on the surface of the roof ([Fig.l]: 4) or arranged on drying supports of all types and shapes so as to facilitate contact between the flow of air passing through ([Fig.l]: 14) and said adsorbent / desorbent ([Fig.l]: 9).

[0023] In a more efficient embodiment, said roof device ([Fig.l]: 1) ([Fig.l]: 4) according to the invention comprises at the roof outlet ([Fig.l]: 4) a device which cools the outgoing air flow ([Fig.l]: 7J), for example by means of a plate heat exchanger (for example of the air / air type), because in fact the outgoing air ([Fig.l]: 7J) has been heated in contact with the solar panels ([Fig.l]: 2) and the atmospheric water generators ([Fig.l]: 10) operate better when the air temperature is lower; moreover it may be interesting to have an air flow ([Fig.l]: 7J) which is variable depending on the air temperature ([Fig.l]: 5N and 5J), the power of the solar irradiation ([Fig.l]: 12) and the electrical power consumed by the atmospheric water generator ([Fig.l]: 10).

[0024] In another interesting embodiment, said device ([Fig.l]: 1) of the roof ([Fig.l]: 4) according to the invention produces water ([Fig.l]: 11) which is made drinkable by means, for example, of filtration, ultraviolet irradiation, and the addition of nutrients.

[0025] In another particular embodiment, said device [Fig.l]: (1) of roof ([Fig.l]: 4) according to the invention comprises fans ([Fig.l]: 6 and 8) and an atmospheric water generator ([Fig.l]: 10) which are supplied with electricity by at least part of the electrical power of the photovoltaic solar panels ([Fig.l]: 2). This electrical power supply may also comprise intelligent management of the electrical production, batteries and other devices for storing electricity and thermal energy, so as to supply the fans ([Fig.l]: 6 and 8) and the water generator ([Fig.l]: 10) during periods of low light or during at least part of the night ([Fig.l]: N)

[0026] In another particular embodiment, said roofing device ([Fig.l]: 1) ([Fig.l]: 4) according to the invention, comprises at least part of the roofing ([Fig.l]: 4), possibly located under said photovoltaic surface ([Fig.l]: 2), or at least part of the vertical walls of the construction ([Fig.l]: 14), which is planted. Detailed description of the invention

[0027] [Fig.l] The invention is now described more precisely thanks to the attached figure which represents in sectional view the basic diagram of a roof ([Fig.l]: 4) covered with photovoltaic solar panels ([Fig.l]: 2) which supply electricity to an atmospheric water generator ([Fig.l]: 10) whose performance has been increased.

[0028] A construction ([Fig.l]: 14) of the “building” type has a flat roof ([Fig.l]: 4); but said roof ([Fig.l]: 4) can also have any type of shape and inclination. The roof ([Fig.l]: 4) is covered with an airtight photovoltaic surface ([Fig.l]: 2). This photovoltaic surface ([Fig.l]: 2) can be composed of photovoltaic solar panels juxtaposed with each other, possibly with a sealing joint between them. The space ([Fig.l]: 3) between the roof ([Fig.l]: 4) and the photovoltaic surface ([Fig.l]: 2) comprises an adsorbent / desorbent ([Fig.l]: 9) capable of absorbing and desorbing water vapor depending on its temperature, and is arranged in a thin layer on the surface of said roof ([Fig.l]: 4). Said adsorbent / desorbent is for example composed of Gel beads of Silica. At least two openings ([Fig.l]: 15 and 13) allow, thanks to fans ([Fig.l]: 6 and 8), to circulate a flow of air ([Fig.l]: 14) from outside on either side of this space ([Fig.l]: 3). At night ([Fig.l]: N) (represented by the lunar symbol) the ambient outside air ([Fig.l]: 5N) is introduced inside the space ([Fig.l]: 3) so that it humidifies the adsorbent ([Fig.l]: 9), then it comes out ([Fig.l]: 7N) with lower humidity. During the day ([Fig.l]: J) (represented by the sun symbol) a flow of ambient outside air ([Fig.l]: 5J) is introduced into the space ([Fig.l]: 3) so that it is humidified upon contact with said adsorbent ([Fig.l]: 9), then exits ([Fig.l]: 7J) with increased humidity. Indeed, in general, said adsorbent / desorbent adsorbs more humidity when its temperature is low; and desorbs more humidity when its temperature is high. The incoming air flow ([Fig.l] : 5J), the day, is therefore heated in contact with the interior surfaces of said photovoltaic surface (2) which receives and absorbs solar radiation ([Fig.l] : 12), then comes out ([Fig.l] : 7J) and is directed towards an atmospheric water generator ([Fig.l] : 10) which condenses the water vapor ([Fig.l] : 11) of said air flow ([Fig.l] : 7J). As the relative humidity of said outgoing air flow ([Fig.l] : 7J) is higher than the relative humidity of the ambient air ([Fig.l] : 5J), said water generator ([Fig.l] : 10) will therefore produce more water ([Fig.l] : 11) than if it had only treated the non-humidified ambient air ([Fig.l] : 5J). The performance (in terms of water production depending on the electrical energy consumed) of the atmospheric water generator ([Fig.l]: 10) was therefore increased due to the use of an adsorbent ([Fig.l]: 9) (here as an example silica gel beads) which was spread over the entire surface of the roof ([Fig.l]: 4).The gain in water production can then reach twice, when the temperature and humidity conditions of the ambient air are ideal. In addition, thanks to the photovoltaic surface ([Fig.l]: 2) which shades the roof ([Fig.l]: 4) and thanks to the layer of silica gel ([Fig.l]: 9) which lowers the air temperature when it is in the desorption phase (during the day), the roof ([Fig.l]: 4) is better insulated against external heat. Examples

[0029] An example of an embodiment includes an industrial building whose roof ([Fig.l]: 4) is flat and horizontal and is made of concrete and has sides of 10 mx 20 m or 200 square meters of surface. Concrete being a significant heat accumulator it was necessary to thermally insulate the building while using ecological materials. For this the vertical walls of the building were planted in order to ensure thermal insulation, an aesthetic appearance, an action against the production of greenhouse gases, and the roof was covered, at an average height of approximately 60 cm, with a surface area of ​​220 m2 of photovoltaic solar panels for a peak power maximum of 44 kWp. The panels are juxtaposed to each other so as to produce an airtight surface ([Fig.l]: 2). A row of x5 fans of 100W power each are arranged on each of the two 10 m long sides. The fans on one side will suck the ambient air towards the interior of the roof and the fans on the other side will suck the air from below ([Fig.l]: 3) the photovoltaic surface ([Fig.l]: 2) to redirect it towards a small technical room of 20 m3 which contains three atmospheric water generators ([Fig.l]: 10) with an electrical power of 6 kW each, for a total power of 18 kW. On the surface of the said roof ([Fig.l]: 4) is placed a layer of silica gel ([Fig.l]: 9) 1 cm thick.The total weight of the silica gel is about 2 tons and it can on average adsorb / desorb up to 5% of its weight in water during a temperature variation of 10°C, which commonly happens during day / night cycles, and which therefore corresponds to 2000 kg x 0.05 = 100 liters of water. The said generators ([Fig.l]: 10) are capable of producing a maximum of 450 liters of water per 24 hours when the relative humidity is around 40% and the average temperature is 25°C, or 150 liters of water during the 8 hours of operation during the day. But with the roof device ([Fig.l]: 1) which contains the 2 tons of silica gel, the volume of water ([Fig.l]: 11) which is produced on average is then about 250 liters; which corresponds to an increase in water production of 66%.

[0030] ADVANTAGES OF THE INVENTION

[0031] Ultimately this invention, which uses a photovoltaic surface ([Fig.l]: 2) positioned above a roof (4) and the presence, in good quantity, of an inexpensive adsorbent / desorbent ([Fig.l]: 9), makes it possible to increase the water production ([Fig.l]: 11) of atmospheric water generators ([Fig.l]: 10). The water thus produced could, for example, be used to water the plants positioned on the facade of the building ([Fig.l]: 14)

Claims

Claims

1. - Device (Figure 1: 1) for a photovoltaic roof (Figure 1: 4) (Figure 1: 2), horizontal or at any angle of inclination, and generating atmospheric water (Figure 1: 11) comprising: a cover (Figure 1: 4) covering a construction (Figure 1: 14) supported by a frame and forming a roof (Figure 1: 4) photovoltaic solar panels (Figure 1: 2) positioned above said roof (Figure 1: 4) and arranged so as to form an airtight photovoltaic surface (Figure 1: 2); the surface of this photovoltaic surface (Figure 1: 2) being able to cover all or part of the roof (Figure 1: 4). a space (Figure 1: 3) formed between said roof (Figure 1: 4) and said photovoltaic surface (2), this space (Figure 1: 3) being capable of being crossed by an air flow (Figure 1: 14) coming from the outside (Figure 1: 5N at night and 5J during the day) by means of incoming openings (Figure 1: 15),outgoing openings (Figure 1: 13) and fans (Figure 1: 6 and 8). an atmospheric water generator (Figure 1: 10) which draws in the outgoing air flow (Figure 1: 7N at night or 7 J during the day) from said space (Figure 1: 3) and which extracts (at least in part) its water (Figure 1: 11), characterized in that said space (Figure 1: 3) contains an adsorbent / desorbent (Figure 1: 9) effective for retaining atmospheric water vapor at ambient temperature and returning it at a higher temperature, so that at night (Figure 1: N) an incoming fresh air flow (Figure 1: 5N) passes through said space (Figure 1: 3) and charges the adsorbent (Figure 1: 9) with humidity, and that during the day (Figure 1: J) an incoming outside air flow (Figure 1: 5 J), less cool than that of the night, passes through said space (Figure 1: 3) and is heated in contact with the lower part of the photovoltaic surface (Figure 1: 2) which is heated by solar radiation (Figure 1: 12),so that said heated air flow (Figure 1: 14) takes on the moisture from the adsorbent / desorbent (Figure 1: 9) and then exits (Figure 1: 7J) through the outgoing opening (Figure 1: 13) and feeds said atmospheric water generator (Figure 1: 10).,

2. - Device (Figure 1: 1) for a roof (Figure 1: 4) according to the preceding claim 1, characterized in that the photovoltaic surface (Figure 1: 2) is flat, curved or contains planes inclined, includes transparent or semi-transparent parts, or rainwater recovery devices.

3. - Device (Figure 1: 1) for a roof (Figure 1: 4) according to one of the preceding claims, characterized in that the adsorbent / desorbent (9) of water vapor is chosen from a group comprising, as desired: organometallic frameworks, covalent organic frameworks, zeolitic imidazole frameworks, metal catecholates, metal azolates, zeolites, carbon, charcoal, porous rocks, silica, silica oxide, porous polymers, porous organic polymers, microporous polymers, polymers, crosslinked polymers, salts, metal oxides, porous cages, clathrates, monoliths, organic molecules, lamellae, metals, metalloids, or combinations thereof,

4. - Device (Figure 1: 1) for a roof (Figure 1: 4) according to one of the preceding claims, characterized in that the adsorbent / desorbent (Figure 1: 9) is distributed in a thin layer on the surface of the roof (Figure 1: 4) or arranged on drying supports of all types and shapes so as to facilitate contact between the flow of air passing through (Figure 1: 14) and said adsorbent / desorbent (Figure 1: CH

5. - Device (Figure 1: 1) for a roof (Figure 1: 4) according to one of the preceding claims, characterized in that the air flow (Figure 1: 7J) leaving the roof (Figure 1: 4) is cooled, for example by means of an air / air plate heat exchanger, that its air flow (7J) is variable depending on the air temperature (Figure 1: 5N and 5J), the power of the solar irradiation (Figure 1: 12) and the electrical power consumed by the atmospheric water generator (Figure 1: 10).

6. - Device (Figure 1: 1) for a roof (Figure 1: 4) according to one of the preceding claims, characterized in that the water (Figure 1: 11) produced by the atmospheric water generator (Figure 1: 10) is made potable by means, for example, of filtration, ultraviolet irradiation, and the addition of nutrients.

7. - Device (Figure 1: 1) for a roof (Figure 1: 4) according to one of the preceding claims, characterized in that the fans (Figure 1: 6 and 8) and the atmospheric water generator (Figure 1: 10) are supplied with electricity by at least part of the electrical power of photovoltaic solar panels (Figure 1:2).

8. - Device (Figure 1: 1) for a roof (Figure 1: 4) according to one of the preceding claims, characterized in that at least part of the roof (Figure 1: 4) (possibly located under said photovoltaic surface) or at least part of the vertical walls of the construction (Figure 1: 14) is planted.

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