A number of U.S. companies are leading the charge in developing better batteries for use in conjunction with clean energy systems.

One such is International Battery (IB), an Allentown, Pennsylvania-based company that in 2008 opened the first large format rechargeable lithium-ion cell and battery manufacturing facility in the United States. The battery maker recently revealed a new, 24-volt, 4.1 kilowatt-hour (kWh) storage system that comes ready for integration with various renewable energy systems, including solar. The company came to this conclusion after testing the battery in several evaluation projects.

As it turns out, International Battery will test some of its new product line at the headquarters of Princeton Power, another company working on renewable energy battery development. Princeton Power has agreed to install one of IB’s batteries to the $1.5 million solar energy system atop Princeton’s headquarters in Princeton, New Jersey.

Finally, A123Systems in Watertown, Massachusetts, is using nanotechnology to create lithium-ion storage batteries. While most solar energy systems installed these days are so called grid-tied systems — and don’t come with batteries — energy storage technologies are expected to play an increasing role in helping regulate how energy is dispatched from renewable energy systems, which are generally viewed as a variable source of electricity.