TOUCHSTONE RESEARCH LABORATORY, LTD. — Department of Energy SBIR Phase II: 18c

Description

Phase I analysis results show that in order to potentially meet the round trip and exergetic efficiencies as required by the Department of Energy’s Solar Energy Technology Office, for thermal energy storage in concentrated solar plants, a composite of porous silicon carbide and molten salt phase change material is needed.For a 100 megawatt (electrical) concentrated solar power plant with 12 hour storage capacity, silicon carbide foam and phase change material composite having thermal conductivity of 25 watt per meter kelvin can potentially achieve roundtrip exergy efficiency 90-95%, which meets Solar Energy Technical Office requirements.Porous silicon carbide foam was synthesized directly from coal feedstock in Phase I.The foam’s high porosity and open cellular structure make it ideal for molten salt phase change material containment.Silicon carbide foam’s inherent high-temperature oxidation and corrosion resistance make it ideal for molten salt applications where melting temperatures exceed 750 degrees centigrade.Furthermore applications have been identified for the product as high temperature composite core materials for aerospace structures.The Phase II objective is to scale up the process and demonstrate manufacturability and validate silicon carbide foam produced from coal for successful commercial implementation in Phase III.Anticipated Benefits/Potential Commercial Applications of the Research or Development · Storage enables solar thermal power plants to operate just like a conventional fossil fuel or nuclear power plant, reliably generating electricity when it’s needed most - but without the associated harmful emissions and without any fuel costs · Solar thermal power plants with integrated molten salt energy storage can operate 24/7, providing baseload power for both on-grid and off-grid applications · Integrated energy storage provides the ability to shift electricity generation to meet different profile needs and deliver firm, reliable power at high capacity value · Molten salt thermal energy storage is the lowest capital cost energy storage system · Solar thermal power plants with integrated energy storage are cost-competitive with any new build coal, natural gas, or nuclear technology · Storage allows the facility to produce more than twice as much net annual output (megawatt hours) than any other solar technology · Firm output ensures a more stable and secure transmission system