Cape Town building battery storage to beat price hikes

The City of Cape Town has announced that it has opened bidding to potential tenderers to construct a battery energy storage facility.

The facility will be constructed at the City’s Atlantis Solar PV plant, targeting a minimum rated power output of 5MW and a useable energy storage capacity of 8MW.

This will be able to power 300 homes with an average consumption of 25kWh per day.

“This initiative underscores our commitment to diversifying energy sources, enhancing sustainability, and actively working to lower electricity costs in the wake of Eskom’s outrageous 44% tariff hike proposal,” says MEC for energy Xanthea Limberg.

“Most of these programmes are a first-of-its-kind and our City teams are working incredibly hard in a very tough regulatory and financial environment to make our city more future-fit and to reduce our reliance on Eskom where we can.”

Lindberg said that the city currently uses 75% of the tariff income from electricity sales to buy power from Eskom.

The project is relatively small compared to other planned battery storage projects, such as Eskom’s R11 billion battery energy storage system (BESS), which is designed to be the largest in the country with a 343MW output.

The project was part of an initiative announced by President Cyril Ramaphosa to install 500MW of battery capacity in South Africa.

However, as the City’s executive director of energy, Kadri Nassiep, told Cape Talk, the project is meant to be a pilot project to test the integration of energy storage with its ground-mounted solar plants.

“The intention would be to run it as a pilot from the perspective of understanding the implications, the costing, the requirement in terms of human resources, and the impact on the grid,” Nassiep said.

“That technology will then stay there indefinitely, and the pilot will be naturally transformed and become part of our generation fleet.”

Interested bidders have until 20 November 2024 to submit their applications.

Eskom’s big battery project

Eskom’s aforementioned R11-billion BESS project is years behind schedule and will deliver less than a quarter of the power capacity it was supposed to have by the end of 2024.

A big part of the problem is that the power utility lacks funding. Government’s conditions to provide Eskom with a large debt relief package blocked it from taking on additional debt without Treasury approval.

This has caused a large part of the BESS project to be put on hold.

The project formed part of an initiative announced by President Cyril Ramaphosa to install 500MW of battery capacity in South Africa.

“The Eskom BESS project will act as a proof of concept on the delivery of the first battery energy storage project in South Africa,” Eskom explained.

“The project supports transformational aspects by demonstrating large-scale deployment in support of South Africa’s renewable energy strategy and addresses local overall system challenges.”

According to Eskom’s original timelines, the entire BESS was supposed to be fully commissioned by December 2024.

Eskom announced the appointment of the two successful bidders for the BESS project in July 2022 — South Korean firm Hyosung and Chinese company Pinggao — with a timeline for a rollout over two phases.

Phase 1 would see the installation of 199MW of capacity coupled with 833MWh of energy storage over eight sites, to be fully commissioned by the end of June 2023.

That date was pushed out to December 2023, but ten months later, less than half of the Phase 1 sites have been completed.

Eskom broke ground on the first Phase 1 site at Elandskop in Howick, KwaZulu-Natal, in December 2022.

However, the first site confirmed to be constructed and commissioned was the Hex installation in the Western Cape, boasting 20MW output and 100MWh energy storage, completed in November 2023.

As of October, only three of the 12 sites were completed and operational — Elandskop, Hex, and Pongola.