How to Make Electricity in a Disused Coal Mine
A coal-mine that powered German industry for almost half a century will get a new lease on life when it’s turned into a giant battery that stores excess solar and wind energy.
The state of North-Rhine Westphalia is set to turn its Prosper-Haniel hard coal mine into a 200 megawatt pumped-storage hydroelectric reservoir, which acts like a battery and will have enough capacity to power more than 400,000 homes, said state governor Hannelore Kraft. The town of Bottrop, where people worked the 600 meter (1,969 foot) deep mine since 1974, will keep playing a role in providing uninterrupted power for the country, she said.
Source: University of Duisburg-EssenFull article: https://www.bloomberg.com/news/articles/2017-03-17/german-coal-mine-to-be-reborn-as-giant-pumped-hydropower-battery