Coal mine in Germany turned into renewable energy battery


Germany is turning its hard coal mine Proper-Haniel with half a century of service into a giant battery station to store hydroelectric power and to provide energy to about 400 000 homes. The coal mine will be shut down somewhere next year, and only then, conversion will begin. Germany has hopes to turn other similar facilities to the same end across the country during the next years.

The project is a collaboration of multiple German universities with engineering firms from the private sector, and the government itself. They have been studying the viability onsite since 2012, and the 600-meter-deep mine provides something the area itself couldn’t, elevation, which is crucial to create a pumped storage like the one needed to the present plant, with a reservoir at a higher point feeding another bellow.

The flow of water powers turbines and generates electricity, with the water being pumped up again during periods of low demand.

“In regions such as the Rhineland or the Ruhr area, the lack of relief in the landscape does not provide the necessary height differences [for hydroelectric power]”, explains the project website. “This is where the former coal mines come in”.

The 200-megawatt plant, would take energy from wind turbines, solar panels, biomass sources, and the battery, where water could flow out of the mine during a sunny or windy day, storing the energy as a volume of water in the surface reservoir, until it’s needed.

There are around 26 kilometers of shafts, which can withstand about a million-cubic-meter of water flow inside them, and while similar storage facilities usually use more energy than they generate, they are very important to balance electricity during pick times, when other renewable energy are temporarily unavailable.

If the plant follows the plan, it will help the surrounding region to achieve 30 percent of its energy from renewable sources as early as 2025. The project will also create new jobs and generate economic activity where the local population usually rely on the income from the fossil fuels.

Another benefit of converting these old mines, is that no interference with the natural landscape is needed, and also no rivers have to be rerouted like on other types of hydroelectric power plants. And of course, it takes green energy to a once fossil fuel plant, which is genious.