Solar panels vs. Peltier tiles.?

This is comparing two things that work different ways. These TEG modules give some idea. The temperature difference is 270°C (432°F). This might be hard to achieve anyway. The 56mm x 56mm version gives 14.6W electrical power with a heat flow of 365W. This is an efficiency of power conversion around 4%.

http://espressomilkcooler.com/teg-thermoelectric-p...

The full sun provides around 1000W per square meter. The area of a tile 56mm * 56mm = 0.003136 square meters, so the power from the sun on one tile is only 3.136W. The resulting electrical power is only about 0.125W. It requires an area of 0.365 square meters to get the rated power, with 100% of that focused on the module. This is almost 120 times the area that has to be focused on the tile, difficult to achieve, and it requires some method for tracking of the sun. By the time all the losses are factored in, it might take more like a full 1 square meter of sunlight to get the rated output of 14.6W. The overall efficiency is then only 1.46%. Probably it works better with less focusing and a number of these modules.

It would not be practical to run the cold side at a temperature below ambient (say 30°C) as it would take more power to achieve that colder temperature, so no point. The hot side is limited to 300°C in this model, though there are higher temperature types around. The TEG is not well suited to the sun as a power source, so needs a more complex mechanism. It is more suitable to put on a hot part of a fuel burning stove, where it can deliver steady 24 hours power using what amounts to waste heat.

Solar panels of an area around 1 square meter can be expected to deliver around 150W (10 times as much for the same area of sunlight, cost less because no tracking is required, and off the shelf technology making them easier to use. The efficiency is typically 10-15% for converting the power in the sunlight to electrical power.

However you asked per square inch.. I will just answer per unit area using an equal comparison by focusing sun on one side and cooling the other side to near ambient, using a solar panel the same size as a tile. If an "effective" 0.365 square meters of sunlight was focused on a tile and on a solar panel of the same small size, the tile produces 14.6W, and the solar panel around 36W or a little more. While this is done sometimes with pecialised solar panels, it is at lower concentration, so I don't expect the solar panel can get rid of enough heat for this. There is an inherent difference around 3 times better for the solar panel. With or without "suitable focusing", this same ratio exists. I expect more focusing can be used with a TEG though. Keeping the cold side near ambient looks like a problem, just as keeping the solar panel cool enough is a problem.

I'll guess yes, but I'm doubtful that the TEG can tolerate 600 f.

Traditional solar panels, produce about 3 milliwatts per square inch, when exposed to bright sunlight, typically much less exposed to infrared radiation, and likely to fail if the solar panel temperature exceeds about 200 f.

Not traditional solar panels are designed to be cooled. Improvising may work, but reliable above 10 milliwatts per square inch is unlikely, even with sunlight. Non traditional solar panels (called photovoltaic panels) have been designed for near infrared, but your application likely has broad infrared.

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