thyssenkrupp Industrial Solutions (tkIS) has signed a memorandum of understanding with Germany’s Wismut to deliver renewable underground pumped hydroelectric energy storage (RUPHES) projects in depleted gold mines within South Africa.

The agreement builds on extensive work Professor Frank Winde undertook with a consortium including South African and other German research organisations in 2017. Prof Winde was then with the Mine Water Research Group, and now with Wismut in Germany.

tkIS, with Wismut, is now in a position to offer feasibility studies leading to full project execution for cheap reliable renewable energy. As an added benefit the revitalised mine with a RUPHES provides clean water indefinitely in water scarce regions, it said.

With industrial customers in South Africa paying R1.28/kWh ($0.08/kWh) for electricity by April 2021 and reports that of renewable energy tariffs potentially dropping to R0.40/kWh, these projects have an attractive business case, tkIS says.

The company has engaged with independent power producers and is looking to participate in the fifth independent power procurement program in the country, it says.

“Corporate customers have the option to focus on their core business and allow the IPP to invest in the RUPHES self-generation and thereby use this image-enhancing environmentally friendly and sustainable technology,” the company said.