The availability of cost-effective energy storage technologies with durations from 10 h to several days is key for variable renewable energy sources to become major contributors to electricity generation. In upcoming years, battery prices are expected to remain too high, with energy storage as heat emerging as a cheaper and more promising solution. Even if there is an efficiency penalty in converting heat back to electricity, the low cost of heat storage is a big advantage, especially because this conversion is not always necessary, since heat accounts for about 50% of global energy demand.
Latent heat thermophotovoltaic batteries allow for much lower cost than state-of-the-art electrochemical batteries and can provide both heat and electricity on demand, which make them attractive for grid-scale, long-duration energy storage, and distributed dispatchable cogeneration. This project will develop the first latent heat thermophotovoltaic battery and will demonstrate the technology in a relevant environment for combined heat and power dispatchable generation.