Solar Power Physics

[Schmalz]

I am not sure if this is in the right forum, but I've got a question not so much about solar panel technology but about solar panel physics.

Can anyone tell me what range of the EM spectrum is 'absorbed' by a solar panel and converted into electricity?

I hope the question makes sense. If not, just ask and I shall clarify.

Many thanks in advance.

[emartin00]

The percentage absorbed depends on the wavelength. Here's a basic breakdown.

http://solarcellcentral.com/limits_page.html

[solarix]

The chief limitation of photovoltaic semiconductors is that they only convert a fairly narrow bandwidth. Because the strongest part of the sun's visible band is in the green area, most PV is tuned for green. The really high efficiency type cells (like NASA uses in space) that convert much, much higher percentages of the sunlight (>50%), do it by stacking several layers of differently processed silicon so that one layer gets the green, one layer gets the red, one layer gets the yellow. These cells are very efficient but also very much more expensive. The whole PV technology is quite mature and well understood by the labs. There are books available if you are interested, but pretty difficult to wrap your head around. I've tried to learn it so to be able to explain to customers the PV effect, but tend to fall back on "its magic". The industry hasn't made much progress in better PV technology in a long time - each manufacturer does their best to tweek the cell recipe with different marginal improvements and tradeoffs. The real improvement has come in automating the production process to bring the costs way down the the yields way up.

[Schmalz]

Good reference

The percentage absorbed depends on the wavelength. Here's a basic breakdown.

http://solarcellcentral.com/limits_page.html

Thanks for the reference. It seems to contain what I need.

[Schmalz]

Good explanation

The chief limitation of photovoltaic semiconductors is that they only convert a fairly narrow bandwidth. Because the strongest part of the sun's visible band is in the green area, most PV is tuned for green. The really high efficiency type cells (like NASA uses in space) that convert much, much higher percentages of the sunlight (>50%), do it by stacking several layers of differently processed silicon so that one layer gets the green, one layer gets the red, one layer gets the yellow. These cells are very efficient but also very much more expensive. The whole PV technology is quite mature and well understood by the labs. There are books available if you are interested, but pretty difficult to wrap your head around. I've tried to learn it so to be able to explain to customers the PV effect, but tend to fall back on "its magic". The industry hasn't made much progress in better PV technology in a long time - each manufacturer does their best to tweek the cell recipe with different marginal improvements and tradeoffs. The real improvement has come in automating the production process to bring the costs way down the the yields way up.

Thanks for the explanation, it helps put things into perspective.