Lead acid batteries, once the staple of energy storage and renewable energy systems, are quickly being replaced with lithium-ion (Li-ion) batteries. Li-ion batteries are lighter, charge faster, last longer and hold more stranded energy. They are expected to be the lead technology utilized in BESS and other applications over the next few years.

Other technologies in development include liquid sodium and solid-state batteries. These prototypes are not expected to be widely available for another decade and will require different response tactics not covered in this program.