If you can't stand the heat, get out of the thermal photovoltaic system

Technology Review reports that Kenmore Square start-up MTPV (yes, Kenmore, not Kendall) has won $10 million in funding to develop a new way to turn sunlight into energy - by using the light to heat up a special material that gives off light in a particular wavelength, which is then turned into electricity by standard solar cells.

... 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. ...