New storage method for solar thermal energy

In contrast to energy harvested with photovoltaic cells, solar thermal energy is generally developed as a large power plant, where acres of mirrors precisely reflect sunlight onto a solar receiver. This energy is then used to heat a liquid and drive a turbine that produces electricity. However, the same storage and intermittency problems associated with traditional solar remain.

The advance - described in ChemSusChem - involves a thermochemical storage system that acts like a battery where the transfer is based on heat rather than electricity. During ‘charging’, strontium carbonate decomposes into strontium oxide and carbon dioxide, consuming the thermal energy produced by the sun. When discharging, the recombination of strontium oxide and carbon dioxide releases the stored heat.

According to the researchers, these materials are non-flammable, readily available and environmentally safe. They claim that compared to existing systems, a storage device made using these materials would allow a 10-fold increase in energy density, meaning it would also be cheaper and smaller.