For those of you watching the cutting edge of new technologies, an article in Greentech Media covers the U.S. Department of Energy’s research program ARPA-E,’s public investment and the private investment, in technologies on the ARPA-E list. A direct list of the technologies reveals investments to integrate renewables in demand management, ferment methane into natural gas, develop miniature building heat pumps, and look at new energy storage solutions – including iron flow, all-electron, lithium sulfur, and alkaline batteries, high-power zinc-air and compressed air storage.