Harry, regarding heat into electricity conversion, Professor Eli Yablonovitch of the University of California seems to be doing some interesting stuff, as a side effect of having found a way to throw out photons with sub bandgap energy from photovoltaics.
I’ve seen some hints, like this poster from last year: http://www.zeplerinstitute.ac.uk/sites/www.zeplerinstitute.ac.uk/files/yablonovitch_lecture_poster_web_0.pdf "Thus the effort to reflect band-edge luminescence in solar cells has serendipitously created the technology to reflect all infrared wavelengths, which can revolutionize thermo-photovoltaics. We have never before had such high rear reflectivity for sub-bandgap radiation, permitting step-function spectral control of the unused infrared photons for the first time. This enables conversion from heat[iii] to electricity with >50% efficiency. Such a lightweight “engine” can provide power to electric cars, aerial vehicles, spacecraft, homes, and stationary power plants.” I couldn’t find the full paper though. Mats www.animpossibleinvention.com <http://www.animpossibleinvention.com/> > On 20 Feb 2016, at 19:30, H LV <[email protected]> wrote: > > A typical goal of energy conversion is to convert heat into electricity and > to do it as efficiently as possible. However, if the goal is to convert > electricity into heat the issue of efficiency also arises. > > > An LED is efficient at converting electricity into light but it is > inefficient at converting electricity in to heat. So if you wanted heat and > only had an LED how would you make it more efficient at producing heat? > > Harry
