[herlitzj]

https://www.torus.co/torus-flywheel

[hpb42]

Cool! Thanks for the link.

A 10 kWh flywheel that can charge/discharge at 20 kW (lasts for 20~30 min at this power) costs ~11500 USD + installation and control system.

A Tesla Powerwall has 13.5 kWh capacity, delivers power at ~6 kW and costs ~11500 USD.

That doesn't seem a large difference to me.

[reacharavindh]

That looks very cool. Mechanical energy storage. Any idea what the return efficiency of such a device is? And guesses about its cost?

[herlitzj]

No idea. But interestingly enough, it looks like someone built a grid scale version in PA with funds from the 2008 Recovery Act. There's a final tech report here https://www.smartgrid.gov/project/hazle_spindle_20mws_flywhe... in the Related Docs

[ketzo]

well, if nothing else, that thing looks futuristic as hell

would love to point out in my yard and say "oh, that? that's our mechanical energy storage device"