Abstract
Solar and wind power are now the lowest cost electricity sources, making an urgent need for low-cost long-duration energy storage technologies to turn these intermittent renewables into on-demand power. Long-duration energy storage is defined as an energy to power ratio of more than 10 h. For some applications, hundreds of hours storage capacity will be needed to balance supply and demand. Available storage systems are inadequate: conventional batteries are too expensive, water electrolysis with fuel-cell re-oxidation is too inefficient, and pumped hydro and compressed air are geographically constrained. Reversible solid oxide electrochemical cells operated like flow batteries have the potential to meet the needs of long-duration storage by using ultra-low-cost storage media. This presentation will include: (1) the advantages of such solid oxide batteries using different storage media than the classical H2/O2/H2O chemistry, (2) experimental demonstration and system design, (3) analysis of the storage requirements for reversible electricity storage applications, and (4) techno-economic analysis of novel solid oxide battery systems compared with conventional batteries and flow batteries.
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