Dormant tailings storage facilities (TSFs) have negative effects on their surrounding environments and communities. This study is aimed at determining the financial and practical feasibility of generating energy from the ERGO TSF site, near Brakpan, Johannesburg, as a beneficial post-closure land use option. The beneficial post-closure options investigated were rainwater harvesting and electricity generation from wind power, photo voltaic solar power and a pump storage system constructed on the TSF. Wind power generation and rainwater harvesting from the site were found to be unviable. It was found that a 470 MW (peak capacity) solar photo voltaic plant on top of the ERGO TSF will provide the best solution, both from a practical and financial point of view, yielding a potential internal rate of return (IRR) of 10.7% over 50 years. A pump storage system yields a maximum IRR of 10.3%, but with a substantially smaller generation capacity of approximately 80 MW.