Enlarge / A 110 megawatt (MW) solar plant in Israel’s Negev desert. (credit: OPIC)

With the price of photovoltaics having plunged dramatically, solar is likely to become a major contributor to the electrical generating mix in many countries. But the intermittent nature of photovoltaics could put a limit on how much they contribute to future grids or force us to develop massive storage capabilities.

But photovoltaics aren’t the only solar technology out there. Concentrated solar power uses mirrors to focus the Sun’s light, providing heat that can be used to drive turbines. Advances in heat storage mean that the technology can now generate power around the clock, essentially integrating storage into the process of producing energy. Unfortunately, the price of concentrated solar hasn’t budged much, and photovoltaics have left it in the dust. But some materials scientists may have figured out a way to boost concentrated solar’s efficiency considerably, clawing back some of photovoltaics’ advantage.

Feel the heat

Solar thermal revolves around transfers of heat. Sunlight is used to heat up a working fluid at the mirrors’ focus. That then transfers the heat either to a storage system or directly to another fluid that is used to drive a turbine—typically steam. Higher temperatures typically mean more work can be extracted, making the efficiency of these transfers critical.