Latent heat thermophotovoltaic batteries

Latent heat thermophotovoltaic (LHTPV) batteries store electricity as latent heat at very high temperatures (>1,000°C) and convert this heat back to electricity on demand using thermophotovoltaics (TPVs). In this study, we discuss the techno-economics of LHTPV systems, focusing on parameters such as the round-trip efficiency, energy-to-power ratio, cost per energy and power capacities, and levelized cost of storage. The very low cost of the heat storage media (<4 €/kWh) results in optimal designs with high energy-to-power ratios, fitting long-duration storage (LDS) applications. Shorter-duration storage applications are also possible by increasing the overall round-trip conversion efficiency through cogeneration, that is, combined heat and power (CHP) generation. Results indicate that LHTPV systems can provide lower levelized cost of storage than Li-ion batteries in both LDS and CHP applications. Preliminary experimental results are provided to illustrate the real operation of a LHTPV system.