How does a flywheel energy storage system work?

Since there is very little friction, the flywheel spins continually with very little added energy input needed. Energy can then be drawn from the system on command by tapping into the spinning rotor as a generator. Beacon Power is building the world’s largest flywheel energy storage system in Stephentown, New York.

What is the world's largest-class flywheel power storage system?

The completed system is the world's largest-class flywheel power storage system using a superconducting magnetic bearing. It has 300-kW output capability and 100-kWh storage capacity, and contains a CFRP (carbon-fiber-reinforced-plastic) flywheel.

What is a 20 megawatt flywheel energy storage system?

The 20-megawatt system marks a milestone in flywheel energy storage technology, as similar systems have only been applied in testing and small-scale applications. The system utilizes 200 carbon fiber flywheels levitated in a vacuum chamber. The flywheels absorb grid energy and can steadily discharge 1-megawatt of electricity for 15 minutes.

How efficient is flywheel energy storage?

Datasheet from a long term flywheel energy storage retailer shows their solution at ~86% efficient. The full details give a better view: a 32kWh storage what consumes 55W when idle and consumes 140W when charging/discharging at 8kW. For off-grid where you store the power for 20 hours at time the 55W draw will be pretty costly.

How does a flywheel work?

In this system, the flywheel is levitated by the superconducting magnetic bearing without contact. Therefore, the power loss is minimal although a large flywheel is used, and it is a very practical system which enables stable power generation over a long period.

Can a flywheel save energy?

Wouldn't it be better if you could somehow store that energy when you stopped and get it back again the next time you started up? That's one of the jobs that a flywheel can do for you.