3 ms·

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% efficien

• 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.