A host of new technology developments in energy storage are at the edge of the massive commercial market for solutions to renewable energy intermittency. While storage prices must continue to drop prior to mainstream adoption, there are a few substantial niche markets where storage already makes overwhelming sense. While high performance batteries today can cost between $700 and $800 per kilowatt hour (kWh), and lower performance batteries cost between $400 and $500/kWh, prices are headed downward drastically for those battery companies that survive, several sources at the Renewable Energy Storage Symposium said in San Diego last week.