Quote:Scientists are exploring ways to develop transparent or semi-transparent solar cells as a substitute for glass walls in modern buildings with the aim of harnessing solar energy. But this has proven challenging, because transparency in solar cells reduces their efficiency in absorbing the sunlight they need to generate electricity.
Using perovskites, a Korean research team, led by Professor Seunghyup Yoo of the Korea Advanced Institute of Science and Technology and Professor Nam-Gyu Park of Sungkyunkwan University, has developed a semi-transparent solar cell that is highly efficient and functions very effectively as a thermal mirror.
SOURCEThe semi-transparent solar cells made with the TTEs exhibited an average power conversion efficiency as high as 13.3%, reflecting 85.5% of incoming infrared light. Currently available crystalline silicon solar cells have up to 25% efficiency but are opaque.
Mind explaining that backward stance?
Wicker rinse basin maybe. It seems to me that turning windows into power producing and heat reduction devices would be quite useful.
True, turn them into better heat reduction devices (as compared to non coated windows of course).
Only a small amount of IR is useful for a solar cell. It does help, and in fact there are more photons in the near infrared than there are in the visible, but the absorption band for silicon cuts off at around 1.1 microns. Anything longer wavelength can't get turned into electricity by the solar cell. Perovskites seem to be able to be designed to push the edge of their absorption band a little farther than what you get with silicon, but it won't be much farther. The bulk of the heating, though, is MUCH longer wavelength. That's the stuff you still need to reflect, but doesn't help if it does a double-pass through the solar cell.Originally Posted by EniGma1987
I wonder if these solar cells could be placed on top of a tint like from Huper Optik that reflects 98% of IR and 99.9% UV. That way the solar cells use the IR heat that is coming towards a window as best they can, reflect some of it away, and the stuff that gets through a good portion would be reflected right back out, passing through the cell once again, providing more heat usage and rejection at the same time.
Said it a Hell of a lot better than I.Originally Posted by Mand12
Mind explaining that backward stance? This is perfect for commercial building construction. One of the biggest expenditures is AC due to solar heating of the building, and one of the major ways of making a building more appealing is reducing the thermal load by infrared-reflective paneling on the windows. This is already a market.
The idea that you can take something you're already paying for as part of commercial building construction and instead use it to further reduce your electric bill is astoundingly useful.
So, how again is this useless?
The problem with Solar Panels that don't move with the arch of the sun is that they are extremely inefficient in practice. There may be certain applications that would be perfect for solar windows, but similar to solar roadways, in practice, it will have many issues unless it's priced competitively with existing solar panels which are probably more efficient already.Originally Posted by Mand12
Mind explaining that backward stance?
This is perfect for commercial building construction. One of the biggest expenditures is AC due to solar heating of the building, and one of the major ways of making a building more appealing is reducing the thermal load by infrared-reflective paneling on the windows. This is already a market.
The idea that you can take something you're already paying for as part of commercial building construction and instead use it to further reduce your electric bill is astoundingly useful.
So, how again is this useless?
You then don't get to be able to look out of your windows.
For residential windows, yes, more light is generally good. For commercial windows, it's not even close. Typical commercial windows are in the 20% transmission range, and they do that so the people inside, with relatively weak indoor lighting, can still see the bright, bright outside world through the mostly-reflective window coating. Outside of the visible, they try to get as high a reflectance as possible.
Again, these aren't competing with dedicated solar panels for energy production. They're competing with windows, and they generate way more electricity than those.Originally Posted by Buris
The problem with Solar Panels that don't move with the arch of the sun is that they are extremely inefficient in practice. There may be certain applications that would be perfect for solar windows, but similar to solar roadways, in practice, it will have many issues unless it's priced competitively with existing solar panels which are probably more efficient already.
You will still need triple/quad-pane windows for thermal insulation. What this is competing with is the reflective film they put on the windows, and yes, that film is currently very cheap. But, you have to invent a thing before you make it economical, and the news of this is the invention. Not really warranted to poke holes at how it isn't market-competitive when it didn't exist before these people made it work at all. It will get there, as the cost of installation drops and the cost of electricity grows.Originally Posted by Buris
The idea that this will replace already-existing 'thermal windows' anytime soon is entirely baseless unless you think a triple-pane or quadruple-pane window will cost the same as a semi-transparent solar cell. One day it might be worth it, probably not in the next 10 years.
As said by the above user, for residential applications where you have a few windows, at best 20-30% of your wall area being glazed, it might be an issue, but 20% "darker" windows are not that much of a deal, People do far darker tints in their cars all the time.
Most high rise buildings have much less roof area than south / roughly south facing facade area. Even mid-rise buildings might have roughly equal the above two. So it makes sense tapping into the possibility of using your facade ONTOP of your roof with more traditional / more efficient panels.Originally Posted by Buris
The problem with Solar Panels that don't move with the arch of the sun is that they are extremely inefficient in practice. There may be certain applications that would be perfect for solar windows, but similar to solar roadways, in practice, it will have many issues unless it's priced competitively with existing solar panels which are probably more efficient already.
The silica or whatever material crystals they are using have a set chemistry / molecular structure that leads to this coloration. It is not an option, just like the Crystalline silicon (c-Si) they use in most opaque PVs is that blue-ish color.
Well lemme ask you. do you get more energy collection if you spray on more coats at the cost of transparency? Or is the 13.3% basically all it gives?Originally Posted by superstition222
Perovskites can, indeed, be layered on top of other types of solar cells to increase efficiency. However, another massive utility is their cheapness and spray-on easy - both of which can make quantity of surface area covered outweigh the lack of per square cm efficiency.
I wouldn't worry about the efficiency rate right now. The bigger problem is making perovskites stable enough to be used for commercial products. If, and when, that happens then efficiency will likely have increased. The main reason perovskite is exciting to people is how cheap it is to make.