The Department of Mineral Resources and Energy (DMRE) has confirmed that five substation sites have been specified by Eskom for the public procurement of battery energy storage systems (BESS) with a combined capacity of 513 MW and a minimum of four hours of storage, or at least 2 052 MWh.

A bid submission date of 17:00 on July 5 has been set and preferred bidders will be announced about two months thereafter. The projects are expected to be in operation 24 months after reaching commercial close.

The request for proposals (RFP) was launched on March 7, but the documentation is available for download only once a prospective bidder provides confirmation that the R25 000 documentation fee has been paid.

The IPP Office tells Engineering News that the payment of a documentation fee has been standard practice for all of South Africa’s independent power producer programmes ever since the launch of the first bid window of the renewable procurement programme in 2011.

There have subsequently been six other renewables bidding rounds, as well as a risk mitigation bid window, through which 11 904 MW of mostly wind and solar capacity has been procured from 134 projects. Not all of the projects have reached financial close, however, and a coal procurement programme was abandoned.

The IPP Office tells Engineering News that the total capacity being procured is 513 MW and a minimum installed energy rating of 2 052 MWh has been stipulated, but the actual installed energy rating will be a bidder risk and part of a bidder’s business case.

The programme’s technical parameters have been provided by Eskom Transmission’s system operator, together with transmission grid planning and distribution network planning, which identified the following substation sites:

• Aggeneis 77 MW, at a minimum installed energy rating of 308 MWh;
• Ferrum 103 MW, at a minimum installed energy rating of 412 MWh;
• Garona 153 MW, at a minimum installed energy rating of 612 MWh;
• Mookodi 77 MW, at a minimum installed energy rating of 308 MWh; and
• Nieuwehoop 103 MW, at a minimum installed energy rating of 412 MWh.

All the substations are located in the Northern Cape, and each bid response must be for the full substation energy storage capacity. The department intends selecting a single preferred bidder at each substation.

The RFP does not stipulate the type of battery technology, but the IPP Office stresses that the solution must be capable of performing in accordance with the RFP requirements.

Engineering News was unable to immediately secure information on the local content thresholds that would be applied.

In the advert confirming the launch of the RFP, the DMRE indicated that prospective bidders would also need to complete online registration for each project that a bidder is intending to submit.

A virtual bidders conference would also be hosted prior to the bid submission deadline.

The public procurement of utility-scale BESS follows on from an inaugural Eskom BESS programme, through which an initial 199 MW/833 MWh of battery capacity will be installed across eight Eskom substation sites in four provinces at a cost of R4-billion.

Under a second phase of the Eskom roll-out, a further 144 MW/616 MWh of BESS is expected to be installed by December 2024.