
Flywheel energy storage (FES) works by accelerating a rotor () to a very high speed and maintaining the energy in the system as . When energy is extracted from the system, the flywheel's rotational speed is reduced as a consequence of the principle of ; adding energy to the system correspondingly results in an increase in the speed of th.

Distributed energy resource (DER) systems are small-scale power generation or storage technologies (typically in the range of 1 kW to 10,000 kW) used to provide an alternative to or an enhancement of the traditional electric power system. DER systems typically are characterized by high initial per kilowatt. DER systems also serve as storage device and are often called Distributed energy storage systems (DESS).

Maximum power point tracking (MPPT), or sometimes just power point tracking (PPT), is a technique used with variable power sources to maximize energy extraction as conditions vary. The technique is most commonly used with (PV) solar systems but can also be used with , and .