Dive Summary:

• Martin LaMonica writes for New Scientist on the prospects for flow batteries, predicting "that battery backups for renewables could one day form a constellation of self-sufficient microgrids."
• He points to new designs being rolled out from Primus Power and EnerVault, which are improving upon previous concepts that suffered from high prices and maintenance issues.
• Examples of flow battery use can by seen at Gills Onions in Oxnard, Calif., where a battery is used to supply 600 kilowatts of electricity over six hours for farm equipment, as well as an in-progress project at the Marine Corps Air Station in Miramar, Calif., that will use a 250-kilowatt battery to energy from solar panels.

From the article:

"... Flow batteries are centred around two aqueous electrolytes, which are held in separate tanks when the battery is idle. To get electricity from it, the liquids are pumped into a chamber separated by a membrane, sparking an electron-producing chemical reaction across the membrane. To store energy, an external current is applied across the membrane and the process works in reverse. ..."