Solar and Wind Energy May Be Nice, but How Can We Store It?

Re:Solar and Wind Energy May Be Nice, but How Can We Store It? by infiniteparamtr on Wednesday April 06, 2016 @12:28AM (#11436609)

I haven't researched the overhead costs, but there are alternative kinetic "batteries" that have been proposed, some of which are already being used:

- Use excess energy generation to drive a gravel-filled train up a few miles of 2% grade, back down the track to drive turbine(s) for energy to be tapped

- Run water up an incline into a reservoir. This can simultaneously serve irrigation purposes. Water level is indicative of available energy to be sent through turbines

- Multi-ton flywheels. I've seen that some fusion experiments use this for massive, quick energy bursts. Magnetism prevents excessive wear/tear on bearings

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Re:Solar and Wind Energy May Be Nice, but How Can We Store It? by basicplus2 on Wednesday April 06, 2016 @01:56AM (#11436896)

composite thin cylindrical flywheels have the best energy storage characteristics

"greater than 400 Wh/kg can be achieved by certain composite materials"

https://en.m.wikipedia.org/wiki/Flywheel_energy_storage

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Re:Solar and Wind Energy May Be Nice, but How Can We Store It? by karterk on Wednesday April 06, 2016 @03:03AM (#11437131)

Flywheels sound exciting but their energy density is about the same as Li Ion batteries (even when carbon composites are used). There are very few large scale deployments of flywheel energy storage systems in the world despite lots of active interest in them. Safety is also a huge concern since if there is a mechanical failure, a huge amount of kinetic energy will have to be safely disposed or you are going to have shrapnels flying everywhere.

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Re:Solar and Wind Energy May Be Nice, but How Can We Store It? by jakeogh on Wednesday April 06, 2016 @04:04AM (#11437366)

You can recharge the flywheel over 10M times. Containment is designed in.

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Re:Solar and Wind Energy May Be Nice, but How Can We Store It? by basicplus2 on Thursday April 07, 2016 @01:34AM (#11444946)

Flywheel systems last considerably longer than batteries, and are generally installed dug into the ground where failures cause no safety issues. Even when not installed underground the vessels fully contain any failure in any case.

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Re:Solar and Wind Energy May Be Nice, but How Can We Store It? by Terr_ on Wednesday April 06, 2016 @05:31AM (#11437674)

In certain failure scenarios I think an energetic flywheel is predictable: Most of the momentum is within the plane of rotation, which is where you can place whatever kind of shielding or catching-material.

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