Solar lensing or bad science

[jetjaguar]

Sorry in advance if this is bad science.

I had a thought today as I was trying to figure out ways to get more "free energy". See picture.

What about the idea of mounting a sort of diffuse fresnel-type lens in front of a solar panel to increase the "surface area" of the sun's rays that get directed to the panels? Sort of like panel glasses or something.

You wouldn't want the lens to strongly focus and heat the panels, just redirect the "edges" to the panels. You wouldn't even need a full lens, just a ring around the panels. Is this crazy thinking? Anyone tried this?

 

[400bird]

Seems like it would be cheaper, easier, and consume the same amount of roof/mount space to just add an extra panel or two.

You can use area as a stand in for the amount of light hitting the panels.
If your lens redirects light from an extra 3 square feet of area, you could probably add an extra solar panel for less cost and produce more power as the solar panel is larger than 3 square feet.

Plus, mounting that lens seems annoying as it needs to withstand the same wind loads as the panel. The solar panel would be a pain to clean as it would be blocked from rain.

But, yes if you make more light (not heat) hit the panels they will produce more power. They may degrade faster as all testing and design is around a normal amount of sun hitting the panels.

 

[Doggydogworld]

Back when PV cells were expensive people made various attempts at lens and/or reflector arrangements. Google "concentrated photovoltaics" for examples. I don't recall standalone lenses like yours, but there were efforts to etch fresnel lenses into the PV glass. One problem with concentration is solar angle - what works when the sun is overhead generally doesn't work at other times of day. As a result, concentrators were typically mounted on trackers.

These efforts mostly died out as PV cells got cheaper. There was a brief renaissance when 40%+ efficient triple junction cells showed up -- they were very expensive but the math kinda worked if you used enough cheap mirrors to concentrate the sun 500x or so.