Internally-heated thermal and externally-cool photovoltaic cascade solar energy system for full solar spectrum utilization
A single-stack, solar power receiver comprising both a thermal absorber layer and a photovoltaic cell layer. The stack includes an aerogel layer, that is optically transparent and thermally insulating (“OTTI”); a spectrally selective high thermal conductivity (“SSTC”) thermal absorber layer; a bottom OTTI layer; and a PV cell layer. The SSTC layer includes a set of fins that substantially blocks solar radiation absorption in the band where PV cells are most sensitive. Photons with energies above or below this band block range are absorbed by the fins and the absorbed heat is conducted to pipes in the fin structure carrying a heated thermal working fluid to heat storage. Photons with energy in the band block range are reflected by the SSTC fins to the PV cell layer. The bottom OTTI aerogel layer keeps the PV cell operating near ambient temperature. The PV cell converts incident solar radiation to electrical energy.
1. A single-stack solar power receiver comprising:
a first aerogel layer, the first aerogel layer including an aerogel that is optically-transparent in the visible and the near-infrared wavelength ranges and thermally-insulating in the mid- and far-IR ranges;
a heat absorption layer, adjacent to the first aerogel layer, comprising a fin structure having at least two metallic fins with opposing surfaces facing each other, the fins configured to decrease energy absorption in a given band, a first endpoint of the given band in a range from 500 nm to 800 nm at a high energy end and a second endpoint of the given band in a range from 900 nm to 1100 nm at a low energy end, wherein the fins are arranged such that radiation in the given band is reflected between the opposing surfaces and the reflected radiation is transmitted through the fin structure to a subsequent layer in the stack, the heat absorption layer further including pipes connected to the fins for carrying a thermal fluid;
a second aerogel layer adjacent to the heat absorption layer; and
a photovoltaic cell layer adjacent to the second aerogel layer.
2. The single-stack solar power receiver according to claim 1 , wherein the given band is from 750 nm to 1100 nm.
3. The single-stack solar power receiver according to claim 1 , further including an optical concentrator that is located between a source of solar radiation and the first aerogel layer.
4. The single-stack solar power receiver according to claim 1 , wherein the fins are connected as a set of parallel fins.
5. The single-stack solar power receiver according to claim 1 , wherein the fins are connected as a grid of fins.
6. The single-stack solar power receiver according to claim 1 , wherein the fins are tilted at an angle to an axis of the stack.
7. The single-stack solar power receiver according to claim 1 , wherein the fins are coated with a film that decreases the energy absorption in the given band.
8. The single-stack solar power receiver according to claim 7 , wherein the film coating the fins is a composite film comprising dielectric layers.
9. The single-stack solar power receiver according to claim 1 , further including a heat storage device connected to the pipes that are connected to the fins.
10. The single-stack solar power receiver according to claim 1 , further including a heat energy conversion device connected to the pipes that are connected to the fins.
11. The single-stack solar power receiver according to claim 1 , wherein the second aerogel layer includes an aerogel that is optically-transparent in the visible and the near-infrared wavelength ranges and thermally-insulating in the mid- and far-IR ranges.
12. A single-stack solar power receiver comprising:
a first aerogel layer, the first aerogel layer including an aerogel that is optically-transparent in the visible and the near-infrared wavelength ranges and thermally-insulating in the mid- and far-IR ranges;
a heat absorption layer, adjacent to the first aerogel layer, comprising at least two metallic fins, the fins configured to decrease energy absorption in a given band, a first endpoint of the given band in a range from 500 nm to 800 nm at a high energy end and a second endpoint of the given band in a range from 900 nm to 1100 nm at a low energy end, wherein the fins are arranged such that radiation in the given band is reflected from and the reflected radiation is transmitted to a subsequent layer in the stack, the heat absorption layer further including pipes connected to the fins for carrying a thermal fluid, wherein the fins are coated with a composite film comprising dielectric layers and metal layers that decrease the energy absorption in the given band;
a second aerogel layer adjacent to the heat absorption layer; and
a photovoltaic cell layer adjacent to the second aerogel layer.
13. A single-stack solar power receiver comprising:
a first aerogel layer, the first aerogel layer substantially transparent in a first band from 0.3 μm to 1.8 μm and substantially insulating in a second band greater than 2.5 μm;
a heat absorption layer, adjacent to the first aerogel layer, comprising a fin structure having at least two metallic fins with opposing surfaces facing each other, the fins configured to decrease energy absorption in a given band, a first endpoint of the given band in a range from 500 nm to 800 nm at a high energy end and a second endpoint of the given band in a range from 900 nm to 1100 nm at a low energy end, wherein the fins are arranged such that radiation in the given band is reflected between the opposing surfaces and the reflected radiation is transmitted through the fin structure to a subsequent layer in the stack, the heat absorption layer further including pipes connected to the fins for carrying a thermal fluid;
a second aerogel layer adjacent to the heat absorption layer; and
a photovoltaic cell layer adjacent to the second aerogel layer.
14. The single-stack solar power receiver according to claim 13 , wherein the given band is from 750 nm to 1100 nm.
15. The single-stack solar power receiver according to claim 13 , further including an optical concentrator that is located between a source of solar radiation and the first aerogel layer.
16. The single-stack solar power receiver according to claim 13 , wherein the fins are connected as a set of parallel fins.
17. The single-stack solar power receiver according to claim 13 , wherein the fins are coated with a film that decreases the energy absorption.
18. The single-stack solar power receiver according to claim 13 , further including a heat storage device connected to the pipes that are connected to the fins.
19. The single-stack solar power receiver according to claim 13 , further including a heat energy conversion device connected to the pipes that are connected to the fins.
20. A single-stack solar power receiver comprising:
a first aerogel layer, the first aerogel layer including an aerogel that is optically-transparent in the visible and the near-infrared wavelength ranges and thermally-insulating in the mid- and far-IR ranges;
a heat absorption layer, adjacent to the first aerogel layer, comprising a fin structure having at least two metallic fins with opposing surfaces facing each other, the fins configured to decrease energy absorption in a given band, a first endpoint of the given band in a range from 300 nm to 700 nm at a high energy end and a second endpoint of the given band in a range from 800 nm to 900 nm at a low energy end, wherein the fins are arranged such that radiation in the given band is reflected between the opposing surfaces and the reflected radiation is transmitted through the fin structure to a subsequent layer in the stack, the heat absorption layer further including pipes connected to the fins for carrying a thermal fluid;
a second aerogel layer adjacent to the heat absorption layer; and
a photovoltaic cell layer adjacent to the second aerogel layer.