CN104682856A - Spectral solar photovoltaic system - Google Patents

Abstract

The embodiment of the present invention discloses a spectrum-splitting solar photovoltaic system, including a first light-splitting unit, a second light-splitting unit, a third light-splitting unit, a first battery group, a second battery group, a third battery group and a fourth battery group, Since the first battery group, the second battery group, the third battery group and the fourth battery group are four single-junction photovoltaic battery groups with different band gaps with relatively mature preparation technology, high photoelectric conversion efficiency for the corresponding wave band, and low cost , instead of the tandem photovoltaic cells with high preparation process and severe heat generation, the structure is simple and easy to realize, which reduces the preparation cost of the broadband photovoltaic system, thus improving the application range of the broadband photovoltaic system. At the same time, the optical path is simple and the loss is low , improving the photoelectric conversion efficiency of broadband photovoltaic systems.

Description

A split-spectrum solar photovoltaic system

technical field

The invention relates to the field of photovoltaics, in particular to a spectrum-split solar photovoltaic system.

Background technique

Solar energy is the most abundant renewable energy on the earth, and the realization of efficient utilization of solar energy is of great significance to the future energy structure adjustment of human society. Please refer to Figure 1, Figure 1 is the spectral energy distribution diagram of solar radiation, as shown in Figure 1, the solar radiation spectrum is very wide, and 90% of the solar radiation spectral energy received on the surface is located in the broad spectrum band range of 280nm-2500nm .

In order to improve the utilization of solar energy, people have developed a stacked multi-junction wide-spectrum photovoltaic system on the basis of photovoltaic cells made of single-junction semiconductor materials. Please refer to Figure 2. The schematic diagram of the spectrum photovoltaic system, as shown in Figure 2, the photovoltaic system divides the solar spectrum into several continuous bands, and uses a plurality of semiconductor materials with the best match between the band gap and these bands to make photovoltaic cells, and according to the band gap The order of width from large to small is stacked layer by layer from the outside to the inside. Light with a short wavelength and high intensity is used by the outermost wide-gap material cell, and light with a longer wavelength can be transmitted in to be used by a material cell with a narrower band gap. In this way, the spectral response range of the photovoltaic system can be expanded, and the light energy can be converted into electrical energy to the maximum extent.

However, the stacked multi-junction wide-spectrum photovoltaic system has a high loss due to the complex connection of devices at all levels, light energy transmission and circuit connection, and because its stacked structure needs to use expensive high-performance photovoltaic materials, it is also necessary to consider various The problem of matching the interlayer current and the lattice structure, and the complex thermal management when the number of layers is arranged, will lead to expensive preparation costs.

Therefore, there are technical problems of high manufacturing cost and low photoelectric conversion efficiency of stacked wide-spectrum photovoltaic systems in the prior art.

Contents of the invention

Embodiments of the present invention provide a split-spectrum solar photovoltaic system to solve the technical problems of high manufacturing cost and low photoelectric conversion efficiency of stacked wide-spectrum photovoltaic systems in the prior art.

An embodiment of the present invention provides a split-spectrum solar photovoltaic system, including:

The first light-splitting unit has a first transmission end and a first reflection end, and the first light-splitting unit can divide the incident solar broad spectrum into a reflected first band spectrum and a transmitted second band spectrum;

The second light splitting unit is arranged at the first reflection end, the second light splitting unit has a second transmission end and a second reflection end, and the second light splitting unit can split the first band spectrum into reflected second light splitting units. A sub-band spectrum and a transmitted second sub-band spectrum;

The third light-splitting unit is arranged at the first transmission end, the third light-splitting unit has a third transmission end and a third reflection end, and the third light-splitting unit can divide the second band spectrum into reflected first The third sub-band spectrum and the projected fourth sub-band spectrum;

The first battery group is arranged at the second reflective end, and is used to convert the solar energy of the first sub-band spectrum into electrical energy, and the material of the first battery group is suitable for the photoelectricity of the solar energy of the first sub-band spectrum. The conversion efficiency exceeds the first preset value;

The second battery group is arranged at the second transmission end, and is used to convert the solar energy of the second sub-band spectrum into electric energy, and the material of the second battery group is suitable for the photoelectricity of the solar energy of the second sub-band spectrum. the conversion efficiency exceeds the second preset value;

The third battery group is arranged at the third reflective end, and is used to convert the solar energy of the third sub-band spectrum into electric energy, and the material of the third battery group is suitable for the photoelectricity of the solar energy of the third sub-band spectrum. the conversion efficiency exceeds the third preset value;

The fourth battery group is arranged at the third transmission end, and is used to convert the solar energy of the fourth sub-band spectrum into electric energy, and the material of the fourth battery group has a positive effect on the photoelectricity of the solar energy of the fourth sub-band spectrum. the conversion efficiency exceeds the fourth preset value;

Wherein, the first battery pack, the second battery pack, the third battery pack and the fourth battery pack are single-junction battery packs.

Optionally, the first light-splitting unit is specifically a first long-pass thin-film interference cut-off filter, the first band spectrum is a short-band spectrum of 350nm-800nm, and the second band spectrum is a spectrum of 850nm-2000nm.

Optionally, the first long-wave pass thin-film interference cut-off filter is placed at an angle of 45° to the optical path of the incident sunlight.

Optionally, the second light splitting unit is specifically a second long-wave pass thin-film interference cut-off filter, the first sub-band spectrum is a 350nm-500nm spectrum, and the second sub-band spectrum is a 500nm-800nm spectrum.

Optionally, the first battery group is an amorphous silicon photovoltaic battery group, and the second battery group is a gallium arsenide photovoltaic battery group.

Optionally, the optical path of the sunlight reflected by the second long-wave pass thin-film interference cut-off filter and the first long-wave pass thin-film interference cut-off filter is placed at an angle of 45°.

Optionally, the third light splitting unit is specifically a third long-wave pass thin-film interference cut-off filter, the third sub-band spectrum is 850nm-1100nm spectrum, and the fourth sub-band spectrum is 1200nm-2000nm.

Optionally, the third cell group is specifically a monocrystalline silicon photovoltaic cell group, and the fourth cell group is specifically a gallium antimonide photovoltaic cell group.

Optionally, the third long-wave pass thin-film interference cut-off filter is placed at an angle of 45° to the light path of sunlight transmitted by the first long-wave pass thin-film interference cut-off filter.

One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

1. Due to the use of four single-junction photovoltaic cell groups with different band gaps with relatively mature preparation technology, high photoelectric conversion efficiency for the corresponding wave band, and low cost, it replaces the stacked photovoltaic cells with high preparation technology and serious heat generation. It is simple and easy to realize, and reduces the preparation cost of the broadband photovoltaic system, thus improving the application range of the broadband photovoltaic system. At the same time, the optical path is simple and the loss is low, and the photoelectric conversion efficiency of the broadband photovoltaic system is improved.

2. Since the entire photoelectric conversion process does not require the use of laminated photovoltaic cells with complex preparation processes, the structure is simple and easy to implement. At the same time, the optical path of the entire photovoltaic system is simple, and the wide spectrum of solar energy occupies more than 90% of the energy in each band of 350nm-2000nm All of them can be converted by the corresponding photovoltaic cells with high photoelectric conversion efficiency, and the photoelectric conversion of solar energy has a wide spectral range, and the utilization rate of photoelectric conversion is high.

Description of drawings

Fig. 1 is the spectral energy distribution diagram of solar radiation;

2 is a schematic diagram of a stacked multi-junction broadband photovoltaic system in the prior art;

3 is a schematic diagram of a split-spectrum solar photovoltaic system provided by an embodiment of the present invention;

Figure 4 is an example diagram of a split-spectrum solar photovoltaic system provided by an embodiment of the present invention;

5A is a schematic diagram of the simulation results of the transmission spectrum of the first long-wave pass thin-film interference cut-off filter provided by the embodiment of the present invention;

5B is a schematic diagram of the simulation results of the transmission spectrum of the second long-wave pass thin-film interference cut-off filter provided by the embodiment of the present invention;

FIG. 5C is a schematic diagram of simulation results of the transmission spectrum of the third long-wave pass thin-film interference cut-off filter provided by the embodiment of the present invention.

Detailed ways

Embodiments of the present invention provide a split-spectrum solar photovoltaic system to solve the technical problems of high manufacturing cost and low photoelectric conversion efficiency of stacked wide-spectrum photovoltaic systems in the prior art.

Please refer to FIG. 3. FIG. 3 is a schematic diagram of a split-spectrum solar photovoltaic system provided by an embodiment of the present invention. As shown in FIG. 3, the split-spectrum solar photovoltaic system includes:

The first light-splitting unit has a first transmission end and a first reflection end, and the first light-splitting unit can divide the incident solar broad spectrum into a reflected first band spectrum and a transmitted second band spectrum;

The second light-splitting unit is arranged at the first reflection end, the second light-splitting unit has a second transmission end and a second reflection end, and the second light-splitting unit can divide the first band spectrum into a reflected first sub-band spectrum and a transmitted first sub-band spectrum Two sub-band spectra;

The third light-splitting unit is arranged at the first transmission end, the third light-splitting unit has a third transmission end and a third reflection end, and the third light-splitting unit can divide the second band spectrum into a reflected third sub-band spectrum and a projected third sub-band spectrum Four sub-band spectra;

The first battery group is arranged at the second reflective end, and is used to convert the solar energy of the first sub-band spectrum into electric energy. In practical applications, in order to ensure the photoelectric conversion efficiency, the material of the first battery group can be set to the Materials whose photoelectric conversion efficiency of solar energy in the sub-band spectrum exceeds the first preset value. Of course, the first preset value can be specifically set according to the actual situation, such as 20%, etc., to meet the needs of the actual situation. make restrictions;

The second battery group is arranged at the second transmission end, and is used to convert the solar energy of the second sub-band spectrum into electric energy. In practical applications, in order to ensure the photoelectric conversion efficiency, the material of the second battery group can be set to the second Materials whose photoelectric conversion efficiency of solar energy in the sub-band spectrum exceeds the second preset value. Of course, the second preset value can be specifically set according to the actual situation, such as 20%, etc., to meet the needs of the actual situation. make restrictions;

The third battery group is arranged at the third reflective end, and is used to convert the solar energy of the third sub-band spectrum into electric energy. In practical applications, in order to ensure the photoelectric conversion efficiency, the material of the third battery group can be set to the Materials whose photoelectric conversion efficiency of solar energy in the sub-band spectrum exceeds the third preset value. Of course, the third preset value can be specifically set according to the actual situation, such as 20%, etc., to meet the needs of the actual situation. make restrictions;

The fourth battery group is arranged at the third transmission end, and is used to convert the solar energy of the fourth sub-band spectrum into electric energy. In practical applications, in order to ensure the photoelectric conversion efficiency, the material of the fourth battery group can be set to the fourth Materials whose photoelectric conversion efficiency of solar energy in the sub-band spectrum exceeds the fourth preset value. Of course, the fourth preset value can be specifically set according to the actual situation, such as 20%, etc., to meet the needs of the actual situation. make restrictions;

Among them, the first battery group, the second battery group, the third battery group and the fourth battery group are all single-junction battery groups with relatively mature preparation technology, high photoelectric conversion efficiency for corresponding wavelength bands, and low cost.

It can be seen from the above part that due to the use of four single-junction photovoltaic cell groups with different band gaps, which have relatively mature preparation technology, high photoelectric conversion efficiency for the corresponding wave band, and low cost, it has replaced the stacked solar cells with high preparation technology and serious heat generation. The multi-layer photovoltaic cell has a simple structure and is easy to realize, which reduces the preparation cost of the broadband photovoltaic system, thus improving the application range of the broadband photovoltaic system. At the same time, the optical path is simple and the loss is low, which improves the photoelectric conversion efficiency of the broadband photovoltaic system .

Please continue to refer to Figure 4, Figure 4 is an example diagram of the split-spectrum solar photovoltaic system provided by the embodiment of the present invention, in the next part, as shown in Figure 4, the first light-splitting unit will be specifically referred to as the first long-wave pass film The interference cut-off filter, the second light-splitting unit being specifically the second long-wave pass thin-film interference cut-off filter, and the third light-splitting unit being specifically the first long-wave pass thin-film interference cut-off filter are taken as examples for detailed description. Of course, in other embodiments, those skilled in the art can use other suitable devices or components for the light splitting unit according to the actual situation, such as a lens or a combination of multiple lenses, etc., so as to realize the long-wave pass film in this embodiment. The function of the interference cut-off filter will not be repeated here.

In this embodiment, due to the wide range of solar energy spectrum to be utilized, it is necessary to cascade the cut-off filter with multi-level basic film systems to expand the high reflection area and achieve high cut-off for the long-wavelength spectrum. spectrum. At the same time, this system intends to use the split light path structure to focus the narrow spectrum of the cut-off filter components on the photovoltaic cells of the corresponding band, so the cut-off filters of these different film structures are required to be at a 45° tilt incident state. In the case of oblique incidence at a large angle, the spectral characteristics of the thin-film filter will be affected by the polarization effect, the cut-off sideband will move to the short-wave direction, the reflection band of the S polarization component will widen, and the reflection band of the P polarization component will decrease. Small. This will lead to a decrease in the transmittance of the filter in the transmission band, a reflection sub-peak in the reflection band, and a decrease in the sideband cut-off. At the same time, the interval between adjacent absorption bands of different semiconductor materials is very narrow and less than 50nm. The spectral characteristics of the designed interference cut-off filter are high when it is obliquely incident at a large angle, and it should have good cut-off sideband characteristics.

For the first long-wave pass thin-film interference cut-off filter, after depolarization optimization design, its spectral range at 45° oblique incidence is: 850nm-2000nm is a high transmission area, and 350nm-800nm is a high reflection area. The cut-off sideband is less than 50nm. The simulation result of its transmission spectrum is shown in Fig. 5A.

For the second long-wave pass thin-film interference cut-off filter, after depolarization optimization design, its spectral range at 45° oblique incidence is: 550nm-800nm is the high transmission area, 350nm-500nm is the high reflection area, and the cut-off edge The band is less than 50nm. The simulation results of its transmission spectrum are shown in Fig. 5B.

For the third long-wave pass thin-film interference cut-off filter, after depolarization optimization design, its spectral range at 45° oblique incidence is: 1200nm-2000nm is the high transmission area, 850nm-1100nm is the high reflection area, and the cut-off edge The band is less than 100nm. The simulation result of its transmission spectrum is shown in Fig. 5C.

As shown in Figure 4, the first long-wave pass thin-film interference cut-off filter 401401 is placed at an angle of 45° to the optical path of the incident sunlight, so that the wide spectrum of the incident solar energy can be divided into the reflected first band spectrum and the transmitted second band spectrum. Two-band spectrum, wherein, the first-band spectrum is a short-wavelength 350nm-800nm spectrum, and the second-band spectrum is a 850nm-2000nm spectrum. It should be noted that, in other embodiments, the spectrum of the first band and the spectrum of the second band can be divided into other segments, such as the spectrum of the first band can be 350nm-1200nm, the spectrum of the second band can be 1200-2000nm, etc. There is no limitation here. Of course, if the ranges of the first band spectrum and the second band spectrum are changed, the subsequent second light splitting unit, third light splitting unit and corresponding battery packs also need to be adjusted accordingly to try to Improving the photoelectric conversion efficiency of the split-spectrum solar photovoltaic system will not be repeated here.

Please continue to refer to FIG. 4, the optical path of the sunlight reflected by the second long-wave pass thin-film interference cut-off filter 402 and the first long-wave pass thin-film interference cut-off filter 401 is placed at a 45° inclination, and the first sub-band spectrum is 350nm-500nm Spectrum, the second sub-band spectrum is 500nm-800nm spectrum.

In this embodiment, the first battery pack is an amorphous silicon photovoltaic battery pack 404 with high photoelectric conversion efficiency in the 350nm-500nm band, and the second battery pack is gallium arsenide (GaAs) with high photoelectric conversion efficiency in the 550nm-800nm band. GaAs) photovoltaic cells 405.

Please continue to refer to FIG. 4, the optical path of the sunlight transmitted by the third long-wave pass thin-film interference cut-off filter 403 and the first long-wave pass thin-film interference cut-off filter 401 is placed at an angle of 45°, and the third sub-band spectrum is 850nm-1100nm Spectrum, the fourth sub-band spectrum is 1200nm-2000nm.

In this embodiment, the third battery pack is specifically a monocrystalline silicon photovoltaic battery pack 406 with high photoelectric conversion efficiency in the 850nm-1100nm band, and the fourth battery pack is specifically an antimony photovoltaic battery pack 406 with high photoelectric conversion efficiency in the 1200nm-1800nm band. Gallium (GaSb) photovoltaic cells 407 .

It can be seen from the foregoing embodiments that when the external incident broad-spectrum sunlight (350nm-2000nm) irradiates the first long-wave pass thin-film interference cut-off filter placed at an angle of 45° to the input optical path, the first long-wave pass thin-film interference cut-off filter The filter outputs the short-band spectrum of 350nm-800nm to the second long-wave pass thin-film interference cut-off filter through the reflection end, and the first long-wave pass thin-film interference cut-off filter outputs the long-wave band spectrum of 850nm-2000nm through the transmission end to the third long-wave pass thin-film interference cut-off filter; the second long-wave pass thin-film interference cut-off filter divides the incident 350nm-800nm waveband into a reflection waveband of 350nm-500nm and a transmission waveband of 550nm-800nm to focus on the amorphous silicon photovoltaic On the battery pack and gallium arsenide photovoltaic cell pack; the third long-wave pass thin-film interference cut-off filter divides the incident 850nm-2000nm band into a reflection band of 850nm-1100nm and a transmission band of 1200nm-2000nm, which are respectively focused on the monocrystalline silicon photovoltaic battery pack and gallium antimonide photovoltaic cell pack. The entire photoelectric conversion process does not require the use of stacked photovoltaic cells with complex preparation processes. The structure is simple and easy to implement. At the same time, the optical path of the entire photovoltaic system is simple, and each band in the 350nm-2000nm, which occupies more than 90% of the energy of the solar broad spectrum, can be controlled by Corresponding photovoltaic cells with high photoelectric conversion efficiency are used for conversion, and the photoelectric conversion of solar energy has a wide spectral range, and the utilization rate of photoelectric conversion is high.

One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

1. Due to the use of four single-junction photovoltaic cell groups with different band gaps with relatively mature preparation technology, high photoelectric conversion efficiency for the corresponding wave band, and low cost, it replaces the stacked photovoltaic cells with high preparation technology and serious heat generation. It is simple and easy to realize, and reduces the preparation cost of the broadband photovoltaic system, thus improving the application range of the broadband photovoltaic system. At the same time, the optical path is simple and the loss is low, and the photoelectric conversion efficiency of the broadband photovoltaic system is improved.

2. Since the entire photoelectric conversion process does not require the use of laminated photovoltaic cells with complex preparation processes, the structure is simple and easy to implement. At the same time, the optical path of the entire photovoltaic system is simple, and the wide spectrum of solar energy occupies more than 90% of the energy in each band of 350nm-2000nm All of them can be converted by the corresponding photovoltaic cells with high photoelectric conversion efficiency, and the photoelectric conversion of solar energy has a wide spectral range, and the utilization rate of photoelectric conversion is high.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these modifications and variations.

Claims (9)

1. a spectral solar energy photovoltaic system, is characterized in that, comprising:

First spectrophotometric unit, has the first transmission end and the first reflection end, and the solar energy wide spectral of incidence can be divided into the first band spectrum of reflection and the second band spectrum of transmission by described first spectrophotometric unit;

Second spectrophotometric unit, be arranged at described first reflection end, described second spectrophotometric unit has the second transmission end and the second reflection end, and described first band spectrum can be divided into the first sub-band spectrum of reflection and the second sub-band spectrum of transmission by described second spectrophotometric unit;

3rd spectrophotometric unit, be arranged at described first transmission end, described 3rd spectrophotometric unit has the 3rd transmission end and the 3rd reflection end, and described second band spectrum can be divided into the 3rd sub-band spectrum of reflection and the 4th sub-band spectrum of projection by described 3rd spectrophotometric unit;

First battery pack, is arranged at described second reflection end, for the solar energy of described first sub-band spectrum is converted to electric energy, the material of described first battery pack to the photoelectric conversion efficiency of the solar energy of described first sub-band spectrum more than the first preset value;

Second battery pack, is arranged at described second transmission end, for the solar energy of described second sub-band spectrum is converted to electric energy, the material of described second battery pack to the photoelectric conversion efficiency of the solar energy of described second sub-band spectrum more than the second preset value;

3rd battery pack, is arranged at described 3rd reflection end, for the solar energy of described 3rd sub-band spectrum is converted to electric energy, the material of described 3rd battery pack to the photoelectric conversion efficiency of the solar energy of described 3rd sub-band spectrum more than the 3rd preset value;

4th battery pack, is arranged at described 3rd transmission end, for the solar energy of described 4th sub-band spectrum is converted to electric energy, the material of described 4th battery pack to the photoelectric conversion efficiency of the solar energy of described 4th sub-band spectrum more than the 4th preset value;

Wherein, described first battery pack, the second battery pack, the 3rd battery pack and the 4th battery pack are single junction cell group.

2. spectral solar energy photovoltaic system as claimed in claim 1, it is characterized in that, described first spectrophotometric unit is specially the first long-pass film interference edge filter, and described first band spectrum is short-wave band 350nm-800nm spectrum, and described second band spectrum is 850nm-2000nm spectrum.

3. spectral solar energy photovoltaic system as claimed in claim 2, is characterized in that, described first long-pass film interference edge filter is 45 ° of slant settings with the light path of incident sunlight.

4. spectral solar energy photovoltaic system as claimed in claim 2, it is characterized in that, described second spectrophotometric unit is specially the second long-pass film interference edge filter, and described first sub-band spectrum is 350nm-500nm spectrum, and described second sub-band spectrum is 500nm-800nm spectrum.

5. spectral solar energy photovoltaic system as claimed in claim 4, it is characterized in that, described first battery pack is amorphous silicon photovoltaic cell group, and described second battery pack is GaAs photovoltaic cell group.

6. the spectral solar energy photovoltaic system as described in claim 4 or 5, is characterized in that, the light path of the sunlight that described second long-pass film interference edge filter and described first long-pass film interference edge filter reflect is 45 ° of slant settings.

7. spectral solar energy photovoltaic system as claimed in claim 2, it is characterized in that, described 3rd spectrophotometric unit is specially the 3rd long-pass film interference edge filter, and described 3rd sub-band spectrum is 850nm-1100nm spectrum, and the 4th sub-band spectrum is 1200nm-2000nm.

8. spectral solar energy photovoltaic system as claimed in claim 7, it is characterized in that, described 3rd battery pack is specially monocrystalline silicon photovoltaic cell group, and described 4th battery pack is specially gallium antimonide photovoltaic cell group.

9. spectral solar energy photovoltaic system as claimed in claim 7 or 8, it is characterized in that, the light path of the sunlight of described 3rd long-pass film interference edge filter and described first long-pass film interference edge filter transmission is 45 ° of slant settings.