Underground pumped-storage hydroelectricity using existing coal mining infrastructure.

Rodolfo Alvarado, André Niemann, Timo Wortberg

Wednesday 1 july 2015

9:15 - 9:30h at Europe 1 & 2 (level 0)

Themes: (T) Water engineering, (ST) Experimental facilities and instrumentation

Parallel session: 8E. Engineering - Computational

The Ruhr region in Germany has been a highly exploited coal mining area for many decades and its network of tunnels with more than 120 mines. Parts of this infrastructure will soon become available for alternative uses since the coal mining facilities in Germany is fading out in 2018. By 2050 it is intended that the country produces 80% of its energy from renewable sources, therefore replacing the energy based on coal and gas. One of the main challenges for making this happen is the energy storage, providing a robust network which can balance surplus and peaks of energy demand over short coverage intervals. Pumped storage hydroelectricity has proved to be an effective solution for this purpose. The network of tunnels in Prosper-Haniel mine has been suggested as a possible lower storage for the development of a pumped-storage project. This infrastructure can hold approximately 600.000 m3 at depths that range between 600-1000 m. These conditions make it suitable to produce large amounts of energy for a short period of time, therefore contributing to balance the energy grid. This paper describes and analyses the hydraulic aspects of using the network of tunnels at Prosper-Haniel mine as a lower storage volume for an underground pumped-storage system. Different operation conditions, i.e. cycles of turbine and pumping modes, as well as wave propagation and hydraulic efficiency of the network are tested. Both construction and operational recommendations are provided based under such analysis. Considering the above, the installed capacity may vary from 200-350 MW for production cycles of at least 4 hours.