Anthem CEO James Cumming says there is a “high probability” of a battery energy storage system (BESS) being integrated into its massive 475 MWac (620 MWdc) Notsi solar PV project in the Free State, with the site having already been permitted to include BESS.

The South African independent power producer started construction on the R9- billion project in March following financial close, which was concluded on the back of 20-year-plus offtake agreements with electricity traders Discovery Green and NOA.

Cumming tells Engineering News & Mining Weekly that it has been standard practice for some time for Anthem to apply for BESS authorisations when seeking environmental and other approvals for new PV or wind developments, even though it has not yet implemented any hybrid renewables-plus-BESS projects.

He also indicates that Notsi is unlikely to be the first Anthem project to integrate BESS, with talks under way with existing offtakers which have shown an interest in using BESS at its existing solar and wind facilities to help match their demand profiles, as well as a willingness to adjust their power purchase agreements to accommodate such matching.

Nevertheless, Cumming is confident that BESS will also be added to the Notsi project, but probably only after it enters into commercial operation following a 26-month construction period.

“We will build the project as a standalone PV site and then, at the appropriate time, approach Eskom as the first step to ensure we’re in agreement with them on how we can interact with the grid should BESS be added.”

“We will then work with the traders, Discovery Green and NOA, on the use case so as to understand what kind of sizing of batteries would be optimal.”

Describing the integration of BESS as the “logical thing to do” as battery prices fall, Cumming believes batteries will become an integral part of its portfolio in future.

Besides allowing it to shift load from large-scale projects such as Notsi, BESS will enable it to offer ancillary services to the grid operator, avoid curtailment, and meet emerging balanced-responsible-party obligations that are required for participation in the South African Wholesale Electricity Market.

For the immediate term, however, Anthem’s focus is on completing the Notsi project itself, which will cover an area spanning 1 000 ha and involve the installation of more than 860 000 solar panels.

A China Energy Engineering Corporation–Northwest Electric Power Design Institute JV has been appointed as the engineering, procurement, and construction contractor, and construction crews are being mobilised while detailed designs are being finalised.

The project has been made possible, Cumming confirms, by the emergence of well-capitalised traders that are able to provide Anthem and its funders with the demand certainty they need to proceed with such a large-scale development.

“In this case, we have two sophisticated and experienced trading businesses with well- developed sales teams that have secured offtake through innovative product offerings, which enables us to focus on doing what we do best, which is developing projects that are big enough to deliver a highly competitive levelised cost of energy, while also amortising the grid connection upgrades required.”

The scarcity of grid in South Africa has increased the cost of connections significantly, which Anthem is mitigating in the case of Notsi by having a project that is large enough to absorb the full cost and initial capacity of the Main Transmission Substation (MTS) being self-built by Anthem and handed over to Eskom to ensure that the electricity can be wheeled through the grid.

“What we’ve done is to effectively utilise the entirety of the 500 MVA transformer that we’re going to install at the Artemis MTS to help amortise the grid-connection cost while making the electricity as affordable as possible for our customers, Discovery Green and NOA,” Cumming explains.

The role of the traders, he adds, is to place those electrons with final customers so that the project can proceed, with this having already been achieved.

“It’s a fantastic thing for the market, as it’s definitely helping to bring more renewables online at scale than would have been the case had it not been for the advent of traders,” he adds, while also stressing that Anthem remains interested in and supportive of future public procurement opportunities, having played a significant role in the public bid windows in the past.