What do coal mines and renewable energy have in common? More than you think, if you fill a disused coal mine with water to store energy from a renewable source – as one German mining town is planning to do.
With 18 million inhabitants, North Rhine-Westphalia is the most populous German state. The region is heavily industrialised, with Westphalia even being nicknamed “the land of coal and steel”.
Germany is currently aiming to move away from conventional sources of energy, in a transition known as the Energiewende. And a small town in North Rhine-Westphalia has found an ingenious way to repurpose one of their mines: by converting it into a giant battery to store renewable energy.
The Prosper-Haniel coal mine is located in the town of Bottrop. It is the last active black coal mine in the region and it employs 4100 people. The mine will close in 2018, after which it will serve as a pumped-storage hydroelectric reservoir.
How Will the System Work?
The system will work by pumping water into a reservoir when renewable energy is being produced, and letting the water flow into a lower chamber when energy is needed. The water flows through turbines which generate electricity. This principle is similar to the “concrete eggs” we presented a few weeks ago.
The Prosper-Haniel mine will be able to store 200MW, enough to power 400,000 homes. As well as allowing a more steady supply to renewable energy, this project will help create jobs for the mining town that will lose its main source of employment.
If the Prosper-Haniel project is successful, it could pave the way for several other disused mines in the region, and perhaps help create employment in North Rhine-Westphalia. Could the land of coal and steel become the land of wind farms and pumped storage? Only time will tell…