Theoretical Efficiency of 85%!
Thermal photovoltaics has been around since the 1960s, but it never produced enough power to compete with solar thermal using steam turbines, or more traditional photovoltaic solar panels. But MTPV Corp. (which stands for micron-gap thermal photovoltaics, the name of the technology they're using) claims it can deliver "an order of magnitude" more power than regular thermal photovoltaics.
Read on for more.
So why thermal photovoltaics? Here's why according to Technology Review:
A conventional solar panel absorbs light from the entire spectrum, but it only converts certain colors efficiently. Much of the energy in the other wavelengths of light goes to waste. As a result, the maximum theoretical efficiency of a conventional solar cell is 30 percent, or 41 percent if the sunlight is first concentrated using a mirror or lens. In a thermal photovoltaic system, light is concentrated onto a material to heat it up. The material is selected so that when it gets hot, it emits light at wavelengths that a solar cell can convert efficiently. As a result, the theoretical maximum efficiency of a thermal photovoltaic system is 85 percent.
That's quite a huge difference! If only we could get thermal photovoltaics to be cost-competitive... On step in that direction has been taken by MTPV.
Using "micron-gaps" between the heated part and the photovoltaic part (instead of the traditional bigger gaps), they claim to have increased the flow of photons to the solar panel by 10 times compared to traditional TPV technology, which makes the whole thing less expensive (it also helps that they one-tenth as much solar-cell material as traditional TPV), but it also means that it can work at lower temperatures.
The 85% efficiency theoretical figure mentioned above is of course very hard to reach, but MTPV's computer models show that 50% efficiency should be possible. So far the company has reached 10 to 15%, which is similar to many other solar panels on the market (not bad). With a bit more progress (it probably hasn't been getting much R&D; effort compared to silicon and thin film solar cells), this technology could become a big player in the solar power world.
Via Technology Review, MTPV
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