From the Star-Tribune in Minnesota, “Xcel looks to harness wind energy for use even when there’s no wind “:
Next spring Xcel Energy Inc., the state of Minnesota and a Virginia-based technology firm will test the first battery in the country capable of storing wind energy.
Well, that’s a bit wrong. Any battery is capable of storing wind energy. I can store wind energy on my laptop battery if I happened to be plugged into an outlet at a time when local wind power projects are producing. The problem isn’t storing electrical energy per se, but doing it economically.
When it is fully charged, the massive sodium-sulfur battery — which weighs about 80 tons — can store 7.2 megawatt-hours of electricity. That’s enough to power 500 homes for about seven hours. It will cost more than $5.4 million to buy and install the battery and analyze its performance. …
Xcel, which invested $3.6 million in the project, expects the battery “to become very important to both us and our customers,” [Xcel Chairman and CEO Dick ] Kelly said.
The article doesn’t say where the other $1.8 million is coming from, but the subtitle notes, “the project … also includes the state and a tech firm,” so maybe it is partly state tax dollars and partly entrepreneurial investment.