Phase Change

The Brayton Energy team will develop an energy storage system that combines thermal storage and a gas turbine to generate power. When the system is charging, an electrically driven heat pump will accumulate thermal energy in a molten salt solution, which can then be discharged later by heating gas and sending it through the generation turbine. Brayton Energy’s innovation lies in their reversible turbine design, in which each turbine acts as the compression stage for the other, whether during charging or discharging. This approach simplifies the system and increases durability.

Well beyond today's maximum operation temperatures of ~1000ºC, Amadeus isl synthetizing new phase change materials (PCMs) with latent heat in the range of 2-4 MJ/kg (an order of magnitude greater than that of typical salt-based PCMs), developing advanced thermal insulation and PCM casing designs, along with novel solid-state heat to power conversion technologies able to operate at temperatures up to 2000ºC. Using these new materials and devices, we aim at realizing the proof of concept of a new kind of extremely compact LHTES device with unprecedented high energy density. The key enabling technologies are: novel PCMs based on the silicon-boron system with ultra-high melting temperature and latent heat, novel refractory lining composites based on carbides, nitrides and oxides for the PCM container walls, advanced thermally insulated PCM casing for ultra-high temperature operation, and novel solid-state heat-to-power converters based on photovoltaic and thermionic effects. In this regard, we will perform the proof of concept of a new kind of hybrid thermionic-photovoltaic (TIPV) device that has been recently formulated theoretically. TIPV cells combine the ionic and photovoltaic phenomena to convert high temperature heat directly into electricity at very high power rates.

Optically-controlled long-term storage and release of thermal energy in phase-change materials