Solar Thermal: Not as Sexy as PV, But More Ready for Prime Time Energy Production
The ability to utilize solar thermal technology after the sun sets is made possible by a storage system that is up to 93% efficient, according to Ausra’s executive vice president John O’Donnell.
High efficiency is achieved because solar thermal plants do not need to convert energy to another form in order to store it and do not rely on battery technology. Flat moving recflectors or parabolic mirrors focus solar energy to generate heat. This heat generates steam that turns turbines, thus generating an electric current.
If you want to generate electricity-at, say, 3 am-heat from the sun can be stored for later use. This gives solar thermal technology the ability to not just produce peak power, but also generate base load electricity.
“Adding solar plants that reliably generate until 10 pm displaces the highest cost alternative power,” said John O’Donnell. “That is the first wave of solar thermal plants. The daily and seasonal variation in grid load in the United States matches solar availability.”__CleanTechnica
This built-in advantage of solar thermal should exist for at least the next 10 to 20 years. In 20 years or so, utility-scale electric storage should allow photovoltaics to mature, and begin producing at the levels of her older sister.