Mulilo has achieved financial close on its flagship Mercury Battery Energy Storage System (BESS) project, a 76 MW / 304 MWh facility near Viljoenskroon in the Free State Province. The milestone follows shortly after the company’s announcement of commercial close on the same scheme, underlining strong execution momentum for the project and for Mulilo’s broader battery storage pipeline.
The Mercury BESS project forms part of South Africa’s Battery Energy Storage Independent Power Producer Procurement Programme (BESSIPPPP) under Bid Window 2 and is being developed under a 15‑year power purchase agreement with the National Transmission Company South Africa (NTCSA). Once operational, the facility will connect to the Mercury Main Transmission Substation (MTS), bolstering grid stability and supporting higher shares of wind and solar in the central grid corridor.
The project also strengthens transmission infrastructure in a key region of South Africa’s network, while contributing to local economic development in the Moqhaka Local Municipality. Mulilo is developing Mercury under a partnership model that includes Reatile as its black economic empowerment (BEE) partner and a local community trust, reinforcing a structure intended to deliver lasting socio‑economic benefits.
Mulilo now holds nine awarded BESS projects across Bid Windows 2 and 3, totalling roughly 3,508 MWh, in addition to participation in three Oasis BESS projects from Bid Window 1 already under construction.
The company’s CEO, Jan Fourie, said the financial close marks an inflection point for Mulilo, demonstrating its ability to deliver bankable energy infrastructure at scale and underscoring the role of battery storage in stabilising South Africa’s grid during the country’s renewable energy transition.
