Solar Thermal Storage Research

[AC_Hacker]

Update on current research being done on thermal storage of solar arrays.

The system hinges on the reversible decomposition of strontium carbonate into strontium oxide and carbon dioxide, which consumes thermal energy. During discharge, the recombination of strontium oxide and carbon dioxide releases the stored heat. These materials are nonflammable, readily available and environmentally safe.

In comparison to existing approaches, the new system could also allow a 10-fold increase in energy density – it’s physically much smaller and would be cheaper to build.

The proposed system would work at such high temperatures that it could first be used to directly heat air which would drive a turbine to produce electricity, and then residual heat could be used to make steam to drive yet another turbine.

In laboratory tests, one concern arose when the energy storage capacity of the process declined after 45 heating and cooling cycles, due to some changes in the underlying materials. Further research will be needed to identify ways to reprocess the materials or significantly extend the number of cycles that could be performed before any reprocessing was needed,

Thermal energy storage using phase change materials has been ongoing for the last 60 years, with reversibility problems being a persistent issue. What is new to me in this study is the very high temperature at which this phase-change is designed to occur, and the double use off the energy as the temperatures decline from one phase to another. Nice example of the exploitation of exergy concepts.

MORE_HERE...

-AC