The method[3]:
- Generate electricity normally.
- Use the electricity to accelerate a flywheel to very high speeds.
- Capture the kinetic energy of the flywheel when needed.
The benefits
- Essentially no maintenance is required.[1]
- The flywheel cannot decay as chemicals in batteries can. While it will eventually spin down due to friction, the timescales of meaningful energy loss are tremendously long.[1]
- Flywheels can operate in environments where chemically-dependent apparatuses (e.g. batteries) can not.[1]
- Flywheels can be spun up and spun down very quickly.[2]
- Efficiencies can be higher than 95%.[3]
- Flywheels have enormous power density, so you can store more energy in the same amount of space. This also means that they can be easily transported in whatever amount(s) is/are necessary.[3]
- Flywheels are incredibly safe, containing no hazardous materials, as batteries do.[3]
- Once flywheels are "discharged", they can be "recharged".
Here's a breakdown of a typical flywheel:
There have been some comments about flywheels running down. My response is that all forms of energy storage lose energy over time in some way. Chemicals in batteries can autodischarge, for example. There is no such thing as 100% efficient energy storage over long timescales.