Sun-free photovoltaics

raelik · Post by **raelik** » Fri Jul 29, 2011 8:09 pm

Saw this today (http://web.mit.edu/newsoffice/2011/sun- ... -0728.html) and thought how it could be used to enhance the energy collection in a pB11 polywell. Line the inside of the vacuum chamber with arrays of these devices, allowing the alphas that escape the deceleration grids to heat these (supposedly) amazingly efficient TPVs and generate electricity. Given the right absorption media, you could conceivably generate electricity from any energetic particle (within reason) attempting to leave the chamber at very respectable efficiencies.

Skipjack · Post by **Skipjack** » Fri Jul 29, 2011 8:21 pm

I am not 100% sure, but I think I read somewhere that these new cells have an efficiency of 3%...

raelik · Post by **raelik** » Fri Jul 29, 2011 8:25 pm

Hah, nice. Yeah, I didn't see any numbers in the article, and couldn't find a paper to reference either.

Skipjack · Post by **Skipjack** » Fri Jul 29, 2011 8:27 pm

Found it!
Of course on NBF, hehehe

http://nextbigfuture.com/2011/07/more-e ... taics.html

The devices achieve a fuel-to-electricity conversion efficiency of about 3%—a ratio

Does not impress me much...

raelik · Post by **raelik** » Fri Jul 29, 2011 8:49 pm

Existing TPVs must be abysmally inefficient for 3% to be a remarkable improvement. Nothing to see here, move along (for Polywell at least).

Giorgio · Post by **Giorgio** » Sat Jul 30, 2011 6:05 am

Don't skip it so easily, while it is only 3% efficient now you have to consider that this is just the first ever design.
Plenty of room to improve it as they collect data and learn.

93143 · Post by **93143** » Sat Jul 30, 2011 8:06 am

I helped build a half-kilowatt thermophotovoltaic testbed device back when I was a co-op student at the Alberta Research Council nine years ago (I got yelled at for firing up the burner while alone in the lab - safety regulations, you see). The efficiency of the cells at the emission temperature was something like 75%, and the total fuel-to-electric efficiency was supposed to be 8% almost right away, and over 12% with an advanced emitter.

Naturally the application was CHP, not straight electrical generation...