In a groundbreaking move, Karst Hydro suggests leveraging the vast network of underground mines in South Africa as colossal batteries to store clean electricity generated from descending water used for cooling. This innovative approach not only offers a sustainable energy storage solution but also presents an opportunity to provide local communities with clean water alongside a reservoir of reliable green energy.
While traditional chemical battery systems typically last for ten to 15 years, pumped hydro storage from repurposed mines boasts a lifespan ranging from 50 to 100 years. This longevity, coupled with the potential for significant capital investment within local communities, positions underground pumped hydro as a viable and sustainable energy storage alternative.
Karst Hydro’s Managing Director, Guy Richards, and Operations Director, Jessica Giger, emphasize the multifaceted benefits of repurposing mines for energy storage. They highlight the potential for South Africa to achieve energy independence and even become a net-energy exporter, leveraging its abundant renewable resources and extensive mining infrastructure.
The proposed solution involves utilizing the kinetic energy of descending water to generate electricity through Pelton wheels installed in mines. Surplus energy during peak production periods is used to pump water from lower reservoirs to upper reservoirs, where it is stored until needed. When electricity demand rises, the stored water is released, generating power through turbine equipment and meeting energy requirements on demand.
Richards and Giger underscore the advantages of underground pumped hydro compared to traditional battery storage systems. While chemical batteries have a limited lifespan of ten to 15 years, underground pumped hydro facilities can operate for several decades without the need for recycling or replacement. Additionally, the majority of capital expenditure for constructing pumped hydro facilities goes back into the local economy, creating employment opportunities and stimulating economic growth within mining communities.
The global trend towards repurposing mines for energy storage underscores the feasibility and cost-effectiveness of this approach. With projects underway in Europe, North America, and Australia, South Africa stands poised to capitalize on its mining infrastructure and renewable energy potential to emerge as a leader in sustainable energy storage solutions. Karst Hydro’s vision represents a transformative step towards harnessing South Africa’s untapped resources for clean energy production and water management, paving the way for a more sustainable and resilient energy future.
