The storage of electricity generated from renewable sources, such as wind power and solar photovoltaics, has always presented a problem for their more widespread adoption. Reversible solid oxide cells (SOCs) offer an alternative to ineffective capacitors or conventional rechargeable batteries.

Conventional SOCs have suffered from long turnaround times in their CO-forming or H₂-forming step. A new approach based on the SOC cycling between hydrogen and methane or water and carbon dioxide, is much less endothermic and so more efficient, according to a team at Northwestern University, USA.

• High efficiency electrical energy storage using a methane-oxygen solid oxide cell
  D. M. Bierschenk, J. R. Wilson, S. A. Barnett,
  Energy Environ. Sci. 2011.
  DOI: 10.1039/C0EE00457J