Storing energy in batteries is expensive, not the best thing to the environment, and inefficient when used on a large scale. The inability to store solar energy over the long-term has been a problem for hte adoption of solar power generation. That is, until now. THe New York Times is reporting on some companies that have found ways to store the energy solar power plants use in a giant thermos.
At Black & Veatch, a builder of power plants, Larry Stoddard, the manager of renewable energy consulting, said that with a molten salt design, â€œyour turbine is totally buffered from the vagaries of the sun.â€ By contrast, â€œif Iâ€™ve got a 50 megawatt photovoltaic plant, covering 300 acres or so, and a large cloud comes over, I lose 50 megawatts in something like 100 to 120 seconds,â€ he said, adding, â€œThat strikes fear into the hearts of utility dispatchers.â€
Thermal storage using molten salt can work in a system like Ausraâ€™s, with miles of piping, but if the salt is spread out through a serpentine pipe, rather than held in a heavily insulated tank, it has to be kept warm at night so it does not solidify, among other complications.
A tower design could also allow for operation at higher latitudes or places with less sun. Designers could simply put in bigger fields of mirrors, proponents say. A small start-up, eSolar, is pursuing that design, backed by Google, which has announced a program to try to make renewable electricity for less than the price of coal-fired power