Submission from @firebendinglemur
The StEnSea project will anchor a hollow, 400-ton concrete sphere with a diameter of 9m at a depth of 500-600m. By emptying the sphere, the storage is charged. When water flows in, electricity is generated, and it is discharged. The power of this prototype is 0.5MW with a capacity 0.4MWh.
Funding for the project is being provided by the German Federal Ministry for Economic Affairs and Climate Action, who is committing nearly €3.4 million, plus around US$4million from the US Department of Energy.
Sperra will manufacture the concrete sphere in Long Beach using a 3D printing process, possibly in combination with traditional concrete construction. It will have an opening at the top, into which a pump turbine will be integrated in a pipe. When a valve is opened, water flows through the pipe into the sphere. The integrated pump runs in reverse and works as a turbine. The water drives the motor, generating electricity. Thus, the storage is discharged.
from Germany, of course. this one at least has a certain whimsy to it. at first i thought they’re going to have mad cavitation problems, but then i saw that they’ll be putting it at 600m deep, which might alleviate the cavitation but has the downside of being 600m deep.
My Notes:
I feel like a 9m sphere is a thing you can just do with normal concrete manufacturing processes? 9m isn’t that big? I’m sure you can just cast a 9m sphere. Actually yeah there’s those experimental Bolwoning things from the 80′s, they were prefab reinforced concrete spheres.
Speaking of Not That Big, like, the reason pumped storage works is because dams are fuckhuge, you usually flood a valley you didn’t have to build or some such. I would for one hate to try and create a valley worth of volume out of 9m spheres.
> This German company, headquartered in Miami, manufactures underwater motor pumps
oh this is a scam by medium sized pump to sell more pump
Even with a pretty pessimistic estimate of capacity for sodium batteries at like, 100Wh/kg you still only need 5 tons of battery to do 0.5MWh which is pretty good I think? You and reggie more or less batterypilled me as of a couple years back.