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Good solar cells are 40ish% efficient? I'm not a photonics engineer but I wonder how much of the total energy is in the visible range. Current solar cells are

Good solar cells are 40ish% efficient? I'm not a photonics engineer but I wonder how much of the total energy is in the visible range. Current solar cells are only cost-effective in limited scenarios, it's nice that these could go in more places but even if they reach cost parity with what we have today, the would be less power. We're going to need to see huge reductions in production cost or energy capture before this becomes viable.

vilhelm_s 12y ago
According to Wikipedia[1], "sunlight provides an irradiance of just over 1 kilowatt per square meter at sea level. Of this energy, 527 watts is infrared radiation, 445 watts is visible light, and 32 watts is ultraviolet radiation". [1] https://en.wikipedia.org/wiki/Infrared#Natural_infrared https://en.wikipedia.org/wiki/Infrared#Natural_infrared
yessql 12y ago
Good research lab solar cells are 40% when actively cooled and concentrating light at 1000x. Good solar panels for homes and solar farms are 15 to 22% efficient.
- pbhjpbhj 12y ago
  It's interesting that efficiency is the key figure that we use. The more pertinent numbers are surely break even point - how many years in a standard installation to return the energy needed to make the panels. The next key figure is probably (in a domestic install) how much of a households energy can be produced with a standard install. In many ways efficiency is irrelevant. If a panel were only 5% efficient but that produced 200% of a families power requirements in a normal install and broke even after 1 year that would be awesome. On the other hand if a panel were 95% efficient and returned 5% of families power requirements and broke even in several decades that would be terrible. It seems a rating that shows how long it takes a panel under [a properly defined] "average" solar illumination to pay for it's own construction (both in money and power) would perhaps be useful and not too difficult to test and verify.

vilhelm_s 12y ago

According to Wikipedia[1], "sunlight provides an irradiance of just over 1 kilowatt per square meter at sea level. Of this energy, 527 watts is infrared radiation, 445 watts is visible light, and 32 watts is ultraviolet radiation". [1] https://en.wikipedia.org/wiki/Infrared#Natural_infrared https://en.wikipedia.org/wiki/Infrared#Natural_infrared

yessql 12y ago

Good research lab solar cells are 40% when actively cooled and concentrating light at 1000x. Good solar panels for homes and solar farms are 15 to 22% efficient.

pbhjpbhj 12y ago
It's interesting that efficiency is the key figure that we use. The more pertinent numbers are surely break even point - how many years in a standard installation to return the energy needed to make the panels. The next key figure is probably (in a domestic install) how much of a households energy can be produced with a standard install. In many ways efficiency is irrelevant. If a panel were only 5% efficient but that produced 200% of a families power requirements in a normal install and broke even after 1 year that would be awesome. On the other hand if a panel were 95% efficient and returned 5% of families power requirements and broke even in several decades that would be terrible. It seems a rating that shows how long it takes a panel under [a properly defined] "average" solar illumination to pay for it's own construction (both in money and power) would perhaps be useful and not too difficult to test and verify.