German energy company wants to build flow batteries in old natural gas caverns
arstechnica.com
arstechnica.com
750 MWh
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160 € per kWh.
LiIon is currently at ~170€/kWh (200USD). LiIon prices will drop more until 2023 but 160€ is still a very good considering this is a research project.
Where do you get the $200/kWh batteries from?
To me, the main three questions are round-trip efficiency, max storage time and environment impact.
https://en.wikipedia.org/wiki/Vanadium_redox_battery mentions 75% to 80% efficiency, though I don't know how well that applies to such big systems.
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.194... mentions a better environmental profile compared to lead acid batteries, but that might be a low bar.
Which is about 10 times the power and more than 10 times the storage of the proposed battery.
It's currently used to shift baseload generation from nighttime to daytime, but it could be used to store solar for evening and nighttime use.
The only real blocker to siting more is that people freak out about local environmental disturbances. It's about 1.5 miles of shore out of hundreds of miles of dunes.
Seriously? If those electrolyte pools were substantially charged, the electrostatic forces would be humongous.
> According to Bloomberg, North Rhine-Westphalia State Governor Hannelore Kraft recently confirmed that a project to turn the coal mine into pumped storage will move forward after mining activities have stopped.