Is this the power plant of the future?
By solar thermal, Khosla Ventures’ Vinod Khosla is referring more specifically to concentrating solar power, as opposed to solar thermal technologies used to provide space heating and hot water in buildings, or conventional solar power, where the sunlight strikes a PV cell and is converted into electricity.
Concentrating solar power uses parabolic mirrors to focus the sun’s energy on a single point, creating high temperatures that generate steam from a fluid. The steam spins a turbine, just as it would in a coal plant, which in turn generates electricity.
Alternatively, the sunlight can be concentrated enough to heat and expand the gas in a Stirling engine to generate electricity (I encourage you to Google “Stirling engine” – very cool technology).
Concentrating solar power is much more efficient than solar photovoltaic (PV), meaning it’s way cheaper. It can be scaled up to several hundred megawatts, putting it in the same utility-scale class as coal and nuclear.
It can be built faster, argues Khosla, and unlike PV it’s not intermittent – heat that’s generated during the day can be stored in rock, water, oil or as steam during the evening or when the sun isn’t shining. That heat can be tapped to generate and dispatch electricity as needed, giving solar thermal the same baseload characteristics as nuclear and coal, but without the emissions or the radioactive waste.