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comment by briandmyers

Probably not original, but I'm surprised more solar implementations don't use a simple passive fresnel lens for a concentrator. Seems like a no-brainer for solar-thermal, and possibly a good idea for PV too, as long as the PV units are capable of handling the extra heat and energy; but I know nothing about PV tech.





kleinbl00  ·  3179 days ago  ·  link  ·  

Worked on thermophotovoltaic cells back in the '90s and holy fuck did we have lensing.

It's really easy with a fresnel to push surface temperatures into "rapid mechanical breakdown" territory. I had a bitchin' 9x11" one as a kid that would not only fry ants, but if you held it right you could crack concrete like popcorn. That shit breaks down electronics about as fast as it breaks down ants.

If you're going to concentrate light like that, it's much easier to pump it into a heliostat. In fact, that's pretty much a heliostat in a nutshell.

Larso  ·  3179 days ago  ·  link  ·  

Solar thermal uses mirrors to concentrate light anyway. Fresnel lenses are kind of messy in that the scatter the light a lot, so you can't shrink the PV as much if you were using a mirror.