Energy storage
Another use is to buffer extreme loads on the power system. For example, [[tokamak]] fusion devices impose very large peak loads, but relatively low average loads, on the electrical grid. The [[DIII-D (tokamak)|DIII-D tokamak]] at [[General Atomics]], the [[Princeton Large Torus]] (PLT) at the [[Princeton Plasma Physics Laboratory]], and the [[Nimrod (synchrotron)|Nimrod synchrotron]] at the [[Rutherford Appleton Laboratory]] each used large [[flywheel]]s on multiple motor–generator rigs to level the load imposed on the electrical system: the motor side slowly accelerated a large [[Flywheel energy storage|flywheel to store energy]], which was consumed rapidly during a fusion experiment as the generator side acted as a [[brake]] on the flywheel. Similarly, the next generation U.S. Navy aircraft carrier [[Electromagnetic Aircraft Launch System#Energy storage subsystem|Electromagnetic Aircraft Launch System (EMALS)]] will use a flywheel motor–generator rig to supply power instantaneously for aircraft launches at greater than the ship's installed generator capacity.