The substation at the Sere wind farm in Vredendal
Electricity utility Eskom has called for bids for the design and construction of a battery energy storage system (BESS) to be installed at the Skaapvlei substation at Vredendal, in the Western Cape, where the group’s 100 MW Sere wind farm is located.
The system should have a minimum power capacity of 80 MW and an energy capacity of 320 MWh. The utility expects to award the contract later this year.
Eskom has received financing for the project from the World Bank, as well as the African Development Bank and New Development Bank and the Skaapvlei project represents Eskom’s first large-scale BESS project, within a bigger BESS roll-out.
In 2018, Eskom indicated that it was considering BESS projects equivalent to 360 MW or 1 440 MWh across multiple sites and the Integrated Resource Plan of 2019 has a 2 088 MW capacity allocation for energy storage.
The utility intends deploying BESS solutions across multiple sites as part of a replacement plan for the 100 MW Kiwano concentrated solar power (CSP) project, which was initially approved, but later abandoned, as part of the World Bank’s $3.75-billion 2010 loan.
Eskom tells Engineering News that development work for other sites is ongoing, with the Skaapvlei site having been selected owing to its alignment with the utility’s project development objectives.
It also stresses that it is open to all technologies, with the size of the BESS for the initial project determined by network capacity.
“[The site] was selected such that the BESS does not lead to network overload or voltage contravention when it is in operation.”
Eskom has invited sealed bids from eligible bidders for the design, engineering, supply, construction, erection, testing and commissioning of a BESS with a minimum of 80 MW/320 MWh of usable capacity for a period of seven months or earlier to a maximum period of nine months.
The successful bidder should also offer plant operation and maintenance services for a period of five years at Koekenaap, in the Western Cape.
Eskom will host a site meeting at the Sere wind farm auditorium at 10:00 on August 20, but it has not made the visit compulsory, owing to the difficulties of travel during South Africa’s Covid-19 lockdown.
“[We believe the site visit] will be possible and Eskom will ensure adherence to all lockdown rules and regulations. Virtual site visits have not been catered for in the advertisement, hence the site visit is not compulsory,” Eskom explained in response to an Engineering News question.
The closing date for bids has been set as 10:00 on September 11, with a prebid clarification meeting to be held virtually at 14:00 on August 27.