A typical system consists of a flywheel supported by connected to a. The flywheel and sometimes motor–generator may be enclosed in a to reduce friction an. Compared with other ways to store electricity, FES systems have long lifetimes (lasting decades with little or no maintenance; full-cycle lifetimes quoted for flywheels range from in excess of 10, up to 10, cycles of use. In the 1950s, flywheel-powered buses, known as, were used in () and () and there is ongoing research to make flywheel systems that are smaller, lighter, cheaper and have a great. Flywheels are not as adversely affected by temperature changes, can operate at a much wider temperature range, and are not subject to many of the common failures of chemical. They are also less potentia.
