LARGE-SCALE ELECTRICITY STORAGE UTILIZING REVERSIBLE SOLID OXIDE CELLS COMBINED WITH UNDERGROUND STORAGE OF CO2 AND CH4

Payne Fellow Robert Braun writes about the electrical storage that is needed on an unprecedented scale to sustain the ongoing transition of electricity generation from fossil fuels to intermittent renewable energy sources like wind and solar power. Here we describe a novel storage method combining recent advances in reversible solid oxide electrochemical cells with sub-surface storage of CO2 and CH4, thereby enabling large-scale electricity storage with a round-trip efficiency exceeding 70% and an estimated storage cost around 3 b kW-1 h-1, i.e., comparable to pumped hydro and much better than previously proposed technologies. June 2015.