Germany turns a coal mine into a huge clean battery that will give electricity to 400,000 homes

That Germany is taking very seriously the change to of renewable energy is nothing new. What is new is to make a coal mine produce electricity without contamination. German scientists are working on that at the Prosper-Haniel mine in the north-west of the country.

Prosper-Haniel is an underground mine that has been producing coal for about 50 years, but the German government has scheduled its definitive closure for 2018. That year work will begin to turn it into a hydropower plant that will provide 200 megawatts of clean energy to supply electricity to More than 400,000 households.

The project has been in development since 2012 and will be the first in a series of similar transformations that will be extended to other deposits in the country. How do you extract electricity from a mine? The solution is ingenious and passes by flooding it with water. Prosper-Haniel has more than 26 kilometers of galleries that penetrate 600 meters inside the earth. The project takes advantage of that, the unevenness, a treasure that does not exist in the region, which is a plain without important natural elevations.

The project will build a huge artificial lake above the mine that will flood the water tunnels. These tunnels converted into conduits will form a circuit that will power a series of turbines just like in a conventional hydroelectric plant, but under water.

A series of wind generators will help the system pump the nearly one million cubic meters of water back to the surface when needed. The project has the advantage that it hardly modifies the landscape on the mine and does not require diverting or modifying the course of any aquifer in the area. Just take advantage of the abundant rains of the region in a controlled manner. Nor does it generate any type of pollution because it does not exploit fossil fuels. Just take advantage of the excavated galleries and their unevenness.

The underground hydroelectric plant is expected to be operational by 2025. The project is not the only one in its class. Similar initiatives are being proposed in the United Kingdom and in an abandoned gold mine in Australia.