Lead–acid batteries have been used for energy storage in utility applications for many years but it has only been in recent years that the demand for battery energy storage has increased.
Lead–acid batteries may be flooded or sealed valve-regulated (VRLA) types and the grids may be in the form of flat pasted plates or tubular plates. The various constructions have different technical performance and can be adapted to particular duty cycles. Batteries with tubular plates offer long deep cycle lives.
Improvements to lead battery technology have increased cycle life both in deep and shallow cycle applications. Li-ion and other battery types used for energy storage will be discussed to show that lead batteries are technically and economically effective. The sustainability of lead batteries is superior to other battery types.
Currently, stationary energy-storage only accounts for a tiny fraction of the total sales of lead–acid batteries. Indeed the total installed capacity for stationary applications of lead–acid in 2010 (35 MW) was dwarfed by the installed capacity of sodium–sulfur batteries (315 MW), see Figure 13.13.
Safety needs to be considered for all energy storage installations. Lead batteries provide a safe system with an aqueous electrolyte and active materials that are not flammable. In a fire, the battery cases will burn but the risk of this is low, especially if flame retardant materials are specified.
The term advanced or carbon-enhanced (LC) lead batteries is used because in addition to standard lead–acid batteries, in the last two decades, devices with an integral supercapacitor function have been developed.