Flywheels

Many storage technologies have been considered in the context of utility-scale energy storage systems. These include:

Background: In recent years there has been a greater interest in making more energy efficient automobiles. A number of plug-in vehicles (PEVs) or hybrid electric vehicles (HEVs) are offered by nearly every automaker today. Although these vehicles offer a cleaner and more energy efficient alternative to traditional petroleum-fueled vehicles mainstream consumer acceptance of these technologies is stymied by considerations of their premium price limited travel range and extended charging times all consequences of current battery technologies.

Background: This invention combines rotating kinetic and pneumatic energy storage into a single device to drastically increase the energy storage density over traditional hydraulic accumulators. Technology Description: Energy is stored in the device by either compressing a gas with the addition of hydraulic fluid or by applying a torque to the device. The two energy domains are coupled as the hydraulic fluid changes the moment of inertia of the device.

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 to the system correspondingly results in an increase in the speed of the flywheel. Most FES systems use electricity to accelerate and decelerate the flywheel, but devices that directly use mechanical energy are being developed.