Some of the “world’s biggest insurance companies” are investigating the advantages of pairing lithium batteries with ultracapacitors in energy storage systems, which can lower costs and extend battery lifetimes, the CEO of an ultracapacitor maker has said.

Fernhill Corporation, a Nevada-headquartered company that invests in and acquires companies for “long-term sustainable cash flow”, has applied to patent a hybrid capacitor-battery energy storage system.

San Diego, California’s ultracapacitor-based energy storage manufacturer Maxwell Technologies has signed a stock purchase agreement with China’s SFIC Fund Management – a significant investor in China’s storage industry – at US$6.32 per share.

A large-scale system combining advanced batteries and ultracapacitor energy storage to provide utility grid services is up and running in North Carolina, according to one of the project’s partners.