JP2006317128A - Photovoltaic power generator and solar heat hot-water unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a means for receiving necessary solar radiation energy even under the condition where an installation area is limited, in a photovoltaic power generator or a solar heat hot-water unit with a wide photoreception face installed limitedly on an elevated spot such as a roof in a south face side under a favorable sunshine condition of a building. <P>SOLUTION: A photoelecromotive force effect due to a silicon material constituting a solar battery cell of the photovoltaic power generator exhibits a peak sensitivity characteristic in a wavelength of a visible light area, the silicon material has a characteristic of transmitting an infrared ray of the solar radiation energy of long wavelength area having a large heating effect, and a solar battery module constituting the photovoltaic power generator is brought into contact onto the photoreception face of the solar heat hot-water unit in an incident route to the solar heat hot-water unit, utilizing the characteristics. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

TECHNICAL FIELD The present invention relates to a solar power generation device that is installed on a roof of a building and converts solar radiation energy into electric energy, and a solar water heater that uses solar heat energy. Using the solar radiation energy in the visible light region having the photovoltaic effect in the broadband wavelength spectrum as the electromotive force of the photovoltaic power generation device, The present invention relates to an effective utilization technique of the solar radiation energy utilized for heating of the solar water heater.

As the global environmental conservation measures such as ratification of the Global Warming Prevention Action Plan, the fossil is a clean energy source that does not use the combustion reaction of fossil fuels such as coal and oil and does not place a burden on the global environment. Devices that directly use solar radiant energy, such as solar power generators and solar water heaters, as a fuel alternative energy source and for securing a lifeline in the event of a large-scale disaster such as an earthquake or storm and flood It is rapidly spreading and expanding not only for use but also for general household use.

  60% of the energy consumed in ordinary households is for heating and hot water supply. The required temperature is 18 ° C for heating, and 42 ° C hot water is used for baths that occupy most of the hot water supply. is there. The heat source necessary for any application is a low-temperature heat source of around 50 ° C., and can be provided by a solar hot water device that can boil hot water at 70 ° C. in summer and 40 ° C. in winter. On the other hand, 25% of the energy consumed in ordinary households is for power and lighting, and all is supplied by electric power.

Electricity can be used not only for power and lighting, but also for heating and hot water supply. However, considering the conversion efficiency from solar radiation energy to electric energy, solar water is used as a heat source for heating and hot water supply. Higher utilization efficiency can be achieved by using the apparatus directly in the form of thermal energy. That is, in order to use solar radiant energy as a household energy source with high efficiency, a solar water heater as a means for directly using solar radiant energy as a heat source, and a solar that photoelectrically converts solar radiant energy and uses it as a power source It is preferable to use both devices of the photovoltaic device together.

The solar power generation device and the solar water heater need to be able to obtain sufficient solar radiation on the light receiving surfaces of the two devices. Therefore, the solar power generator and the solar water heater are installed in the surroundings with high buildings. There is no obstacle to block sunlight, such as mountains or trees, and a wide space with a free southern surface is suitable. As shown in FIG. 6, the solar cell module 31 of the photovoltaic power generation device or the like is placed on the roof on the southern surface side of the building. A solar water heater 30 is installed. However, it is not always possible to ensure a sufficient installation area for planar deployment of the solar cell module 31 and the solar water heater 30 at an appropriate installation location that satisfies the above conditions. Incidentally average four areas 20 to 30 m ² required for installing the solar cell module 3kW scale photovoltaic devices required in the configuration of the family is the area completely covering the south side of the roof of a house, further solar There is no area left to install the hot water system.

As described above, the present invention has been made in view of the current situation where the installation location of the solar power generation device and the solar water heater is restricted, and impairs the utilization efficiency of solar radiation energy by the solar power generator and the solar water heater. The solar power generation device is formed on the light receiving surface of the solar water heating device in the solar light incident path to the solar water heating device in order to photoelectrically convert solar radiation energy and use heat. A battery module is placed, and the solar power generator and the solar water heater are stacked.

As a conventional example characterized by a similar structure, Patent Document 1 is seen, and in this conventional example, a heat collector that collects heat generated by the solar cell module for generating hot water is in contact with the back side of the solar cell module. It is characterized by providing. However, in the present invention, the photovoltaic effect of the silicon material which is the main component of the solar cell module exhibits peak sensitivity at wavelengths in the visible light region of the solar spectrum. According to Patent Document 1, the silicon thin film, which is a component of the module, is a solar power generation device and a solar water heating device that skillfully utilize that a high transmittance characteristic is exhibited together with a transparent electrode composed of indium tin oxide. It is different from the invention.
JP 2002-1000079 A

In order for the solar cell module of the solar power generation device and the light receiving surface of the solar water heater to receive a larger amount of solar radiant energy, the light receiving surface of a large area should be located on the south surface with good sunlight conditions, high buildings, mountains, etc. It is necessary to install it on a high place such as on the roof of a building where solar radiation is not obstructed by it, but if you can secure a sufficient installation place necessary for installing solar cell modules and solar water heaters of solar power generators Without being limited, it provides a means for responding to restrictions on installation locations.

In addition, a transparent top cover made of a glass member is used on the light receiving surface of the solar water heater to protect and keep the heat collecting tube inside, but it is lighter and has higher impact resistance than the glass member. When the top cover is composed of a transparent resin member, the top cover made of the resin member is exposed to strong ultraviolet rays contained in sunlight over a long period of time, and microcracks are generated due to material deterioration of the resin member. Since the amount of solar thermal energy reaching the inside of the solar water heater decreases due to light scattering and the transparency of the top cover is reduced, the thermal effect is reduced. Therefore, the top cover of the solar water heater constituted by a resin member Provides protection from UV rays.

In a solar power generation device and a solar water heater, a solar cell module constituting the solar power generator is placed on a light receiving surface of the solar water heater in a sunlight incident path to the solar water heater, and the solar cell The module and the solar water heater are stacked.

The solar cell module in which the housing bottom surface of the solar cell module is configured with a lightweight transparent resin member is placed on the light receiving surface of the solar water heater, and the solar cell module is also used as the top cover of the solar water heater.

By adopting a stack structure in which a solar cell module is placed on the light receiving surface of a solar water heater, the solar cell module that constitutes the solar power generator uses the energy in the visible light region of solar radiation energy for photoelectric conversion. Further, the energy of the long wavelength region of infrared rays or more having a large thermal effect which the solar radiation energy transmitted through the solar cell module has is used as a thermal energy source of a solar water heater disposed immediately below the solar cell module. Makes it possible to effectively utilize solar radiant energy distributed over a wide wavelength range, and to configure a solar power generation device without impairing the photovoltaic effect of the solar power generation device and the thermal effect of the solar water heater. To meet the restrictions on the installation location of solar cell modules and solar water heaters It is possible to obtain a clean energy.

FIG. 1 is a perspective view showing a first embodiment of the present invention. For the sake of explanation, the solar cell module 20 and the solar water heater 11 which are constituent elements of the solar power generation device are shown separated vertically, but in the embodiment of the present invention, the solar cell module as shown by a chain line arrow in FIG. 20 is placed in contact with the upper surface of the heat collecting part 11 b of the solar water heater 11. A large number of small solar cells are arranged and accommodated in the solar cell module 20 in a planar shape. FIG. 2 is a longitudinal sectional view of each solar battery cell 21 arranged in the solar battery module 20 in FIG. As shown in FIG. 2, the solar cell 21 includes an n-type silicon 21c in which an n-type silicon 21c whose majority carriers governing electrical conduction are electrons and a p-type silicon 21d in which the majority carriers are holes, and an n-type silicon. The transparent electrode 21a is formed on the outer surface of 21c and the transparent electrode 21b is formed on the outer surface of the p-type silicon 21d.

When the solar cell 21 is irradiated with visible light 9a in the solar radiation 9, the photons collide with the atoms, and pairs of electrons and holes are generated. These electrons and holes flow in opposite directions due to the internal electric field and diffusion, and a current is generated. This phenomenon is called a photovoltaic effect. At this time, when the external load 22 is connected to the transparent electrodes 21a and 21b formed on the outer surfaces of the n-type silicon 21c and the p-type silicon 21d constituting the solar battery cell 21, the p-type as shown by the solid line arrow in FIG. A current flows from the silicon 21d through the external load 22 toward the n-type silicon 21c, and the external load 22 can work.

  The photoelectric conversion efficiency of a solar cell depends on the spectral distribution of solar radiation and the sensitivity spectral distribution of solar cells. As shown in FIG. 3, the spectral sensitivity characteristics of an amorphous silicon member that is practically used as a constituent member of the solar battery cell shows a peak at a wavelength of 600 nm, and has a sensitivity over almost the entire range of 400 to 800 nm that is a visible light region. Have. The theoretical photoelectric conversion efficiency of a solar cell composed of an amorphous silicon member is 25%, but it is actually due to various operating principle losses such as carrier recombination and series resistance loss inside the solar cell. Is about 10%, and efforts to improve photoelectric conversion efficiency are still being made.

On the other hand, the peak wavelength of the spectral sensitivity characteristic of the solar cell using single crystal silicon as a constituent member is about 800 nm, and the theoretical conversion efficiency is about 30 to 40%. Is just under 20%. However, since the photoelectric conversion efficiency is higher than that of a solar battery cell using amorphous silicon as a constituent member, it is considered to become the mainstream in the future. In order to improve cost performance by reducing the single-crystal silicon material that is a constituent member of the single-crystal silicon solar cell, technological development for reducing the thickness of the solar cell from about 400 μm to 200 μm or less has been promoted. The thinning of the cell thickness can improve the infrared transmittance having a large thermal effect in solar radiation, and can further improve the thermal effect of the solar water heater disposed immediately below the solar cell module of the present invention.

As shown in FIG. 2, the outer surface of the n-type silicon 21c and the p-type silicon 21d, which are the element portions that generate the photovoltaic effect of the solar battery cell 21, is used to extract electric energy from the solar battery cell 21 to the outside. Transparent electrodes 21a and 21b are formed. Since the transparent electrode 21a does not block the solar radiation 9 that should reach the n-type silicon 21c and the p-type silicon 21d that cause the photovoltaic effect, the transmittance with respect to the radiation spectrum of the solar radiation together with the transparent electrode 21b is shown in FIG. as the transmittance in the visible light region and the infrared region is high, are formed and low resistivity indium tin oxide (I ndium T in O xide) in thin film and the transparent electrode material.

As silicon is used as a lens member of an infrared camera, the transmission spectrum distribution of the silicon member is distributed in a wide spectral region of 1200 nm to 7000 nm on the longer wavelength side than the visible light region of 400 nm to 800 nm, Infrared rays having a high thermal effect are included in this wavelength region. In the present invention, as shown in FIG. 2, the visible light 9 a contained in the solar radiation 9 contributes to the photovoltaic effect of the solar battery cell 21, and the infrared light 9 b that has a longer wavelength than the visible light 9 a and has a thermal effect is the solar battery module 20. The solar cells 21 constituting the solar cell 21 are transmitted through the solar cells 21 and absorbed by the solar water heater 11 disposed immediately below the solar cells 21, thereby contributing to the thermal effect of the solar water heater 11.

A large number of heat collecting pipes 11a are arranged in the heat collecting part 11b of the solar water heater 11 shown in FIG. 1, and a water supply pipe 11e and a hot water supply pipe 11f are connected to the hot water storage part 11d. Infrared rays 9b constituting the radiant energy of the solar radiation 9 are transmitted through the solar cell module 20, absorbed by the heat collecting portion 11b of the solar water heater 11 and transmitted to the water inside the heat collecting tube 11a. The water that has received the heat expands and becomes lighter in specific gravity, moves up in the heat collecting pipe 11a, moves to the upper part of the hot water storage part 11d, and is replaced with low-temperature water at the bottom of the hot water storage part 11d. While repeating this natural circulation, the water temperature inside the hot water storage section 11d gradually rises.

Currently, the solar water heater with the above-mentioned configuration that is commercially available has a heat collection efficiency of 50 to 60%, and realizes extremely high energy utilization efficiency as compared with a photovoltaic power generation apparatus having a photoelectric conversion efficiency of about 10 to 20%. That is, in order to use solar radiant energy with high efficiency, a solar water heater as a means for directly using infrared rays of solar radiant energy as a heat source, and a solar that photoelectrically converts visible light of solar radiant energy and uses it as a power source It is preferable to use both devices of the photovoltaic device together.

FIG. 5A is a side view of the solar cell module 20 and the solar water heater 11 showing an embodiment of the present invention, and FIG. 5B is a side view of a conventional solar water heater 30. In the conventional solar water heater 30 shown in FIG. 5 (b), a transparent member constituted by a glass member is provided on the upper surface of the heat collecting part 30b for the purpose of protecting the heat collecting pipe (not shown) inside the heat collecting part 30b and keeping warm. The top cover 30 a is placed on the top surface of the casing of the solar water heater 30.

In the embodiment according to the present invention, as shown in FIG. 5 (a), the solar cell module 20 protects the solar cells inside by the transparent top cover 20a formed of a glass member, but the bottom surface is lightened. For this reason, the inner solar cells are supported and protected by the bottom cover 20b made of a transparent resin member. Ultraviolet rays and visible rays 9a in the short wavelength region included in the solar radiation energy 9 that deteriorates the resin material that is a constituent member of the bottom cover 20b are obtained by using a silicon member that is a constituent member of the solar battery cell 21 inside the solar battery module 20. Since it does not permeate, the deterioration of the bottom cover 20b formed of the resin member on the bottom surface of the casing of the solar cell module 20 is reduced.

Further, by placing the solar cell module 20 in contact with the upper surface of the heat collecting part 11b of the solar water heater 11, the bottom cover 20b of the solar cell module 20 protects the heat collecting tube inside the solar water heater 11 from above. It can also serve as a surface cover, can eliminate the top surface cover 30a made of a glass member required by the conventional solar water heater 30, and can realize cost reduction and material weight reduction by saving materials. It becomes possible.

It is the disassembled perspective view of the solar cell module mounted in the solar water heater upper surface which shows embodiment of this invention, and has shown the state which isolate | separated the solar water heater and solar cell module for description. It is a longitudinal cross-sectional view of the photovoltaic cell which comprises a photovoltaic module. It is a spectrum distribution figure of the spectral sensitivity characteristic of an amorphous silicon solar cell. It is a spectral transmission characteristic figure of an indium tin oxide (ITO) transparent electrode. Fig.5 (a) is a solar cell module and solar water heater which show embodiment of this invention, FIG.5 (b) is a side view of the prior art example of a solar water heater. It is an image figure of the solar cell module and solar water heater of the solar power generation device installed on the roof of the south side of a house.

Explanation of symbols

9: Solar radiation 9a: Visible light 9b: Infrared ray 11: Solar water heater 11a: Heat collection pipe 11b: Heat collection part 11d: Hot water storage part 11e: Water supply pipe 11f: Hot water supply pipe 20: Solar cell module 20a: Top cover 20b: Bottom Cover 21: Solar cell 21a: Transparent electrode 21b: Transparent electrode 21c: n-type silicon 21d: p-type silicon 21e: pn junction 22: external load 30: solar water heater 30a: top cover 30b: heat collector 31: Solar cell module

Claims (4)

In the solar power generation device and the solar water heater, the solar cell module constituting the solar power generator is placed on the light receiving surface of the solar water heater in the sunlight incident path to the solar water heater. Solar power generator and solar water heater. The solar power generator and solar water heater according to claim 1, wherein the top cover of the solar water heater housing is also used as a solar cell module. 3. The solar power generation apparatus and solar hot water apparatus according to claim 2, wherein the bottom surface of the casing of the solar cell module that constitutes the solar power generation apparatus is formed of a transparent member. apparatus. The solar power generation device and solar water heater according to claim 3, wherein the bottom surface of the casing of the solar cell module constituting the solar power generation device is made of a transparent resin member. Hot water device.

Images