engines compress and heat air with a fuel suitable for an . For example, burning natural gas or heats compressed air, and then a conventional engine or the rear portion of a expands it to produce work. can recharge an . The apparently-defunct
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Flywheel energy storage (FES) works by accelerating a rotor (flywheel) to a very high speed and maintaining the energy in the system as rotational energy. When energy is extracted from the system, the flywheel's rotational speed is reduced as a consequence of the principle of conservation of energy; adding energy. .
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 and. .
TransportationAutomotiveIn the 1950s, flywheel-powered buses, known as , were used in () and () and there is ongoing research to make flywheel systems that. .
• • • – Form of power supply• – High-capacity electrochemical capacitor .
• • • .
GeneralCompared 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), high .
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 potentially damaging to the environment, being. .
• Beacon Power Applies for DOE Grants to Fund up to 50% of Two 20 MW Energy Storage Plants, Sep. 1, 2009 • Sheahen, Thomas P. (1994). . New York: Plenum Press. pp. –78, 425–431.
[pdf] 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), high (100–130 W·h/kg, or 360–500 kJ/kg), and large maximum power output. The (ratio of energy out per energy in) of flywheels, also known as round-trip efficiency, can be as high as 90%. Typical capacities range from 3 to 1.
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