Upconversion to Improve Solar Cell Efficiency

There are experimental cells that respond to three wavelengths and they hope to reach 40-45% conversion soon.

google it and read this

http://www1.eere.energy.gov/solar/solar_cell_structures.html

Very good information.

We are testing to find which type solar cell generates max watts from radiant heat in a dark room or convection from hot air flow in a dark room. Does anyone have any comments, experience, or theory on the subject? BTW: Some solar cells do generate in a dark room. Which type solar cell works best in this application? We need 100 watts continuous.

With low grade heat like that, try a stirling engine. In addition, flue exhaust heat extractors( a radiator through which the flue gas goes to make hot water or hot room air).

In effect you burn corn for heat, so you want to make a condensing furnace for corn so you get max efficiency. Trying to get a little electricity from the waste heat is noit good as it will be 10% or less efficient due to low energy of IR. You would be better off making the flue gas as cool as possible before it goes out the chmney.

What about destructive distillation in the flue from the burned corn? With wood this creates volatiles that condense in the chimney and catch fire from time to time. With wood stoves they are called creosote. WIll corn make an analog creasote type material?

A 100 watt electrical PV generator powered from the stove heat is needed to power the functions of the corn stove. Corn combustion is 98% efficient with no creasote. Exhaust heat is controlled to minimize condensation.

The stirling engine works great and provides adequate power for a corn stove.

Initial test results indicate that the solar cell power may be more cost effective than the stirling engine for corn stove power. We are testing to determine which type solar cell works best from IR and convection in a dark room?

Aurizon,

You wrote:

"There are experimental cells that respond to three wavelengths and they hope to reach 40-45% conversion soon."

I found this link:

http://www.technologyreview.com/read_article.aspx?id=17577&ch=energy

which reads:

"The new semiconductor material can capture these low-energy photons for electricity, which could make solar cells with efficiencies of around 45 percent, compared with 25 percent for conventional cells that use a single semiconductor and 39 percent for cells with layers of mixed semiconductors.

The new semiconductors have three energy bands instead of the usual two (valence and conduction). The third band lies below the conduction band, effectively splitting the gap between the valence and conduction bands into two smaller parts. "This helps low-energy photons to participate in the process because they can excite [electrons] to the [intermediate] band and then up. It's like a stepping stone," says Wladek Walukiewicz of LBNL's Materials Sciences Division, who developed the semiconductor with colleague Kin Man Yu."

Was this what you were talking about? Sounds cool.

Yes, That was one of the links I read that dealt with some of the methods.

45% will be a real killer rate if they can get it, and if they do not want to get rich off it.

They may kill it by wanting such a high royalty that they keep it out of peoples hands.

The gallium arsenide phosphide PV with nitrogen appears to be ideal for the stated application. We contacted RoseStreet Labs Phoenix Arizona for testing material.

Thanks for the help.