Electricity and Energy Minister Kgosientsho Ramokgopa has backed selling surplus South African power to Zambia. Curtailment, where grid operators cap output that the network cannot absorb, has become a growing cost for Eskom and independent producers.
Speaking at the Windaba wind energy conference in Cape Town on 6 October, Ramokgopa said the government was prepared to sign contracts in the national interest to sell spare capacity across the continent. Zambia has formally asked South Africa for 5,000MW of electricity.
The proposal comes as curtailment becomes a financial strain. Curtailment payments owed to producers had built up a backlog of about R2bn by June 2026. Holding back generation capacity could cost the economy up to R49bn a year.
| Indicator | Figure |
|---|---|
| Zambia’s requested supply | 5,000MW |
| Curtailment payment backlog (June 2026) | ~R2bn |
| Potential annual cost of capped generation | Up to R49bn |
| Eskom export revenue, 2025/26 | R18.8bn |
| Regional electricity sold by Eskom, 2024/25 | 14,532GWh |
| Net regional sales, 2024/25 | 6,962GWh |
| New transmission lines planned | 14,500km |
South Africa already supplies much of the region. Eskom sold R18.8bn of electricity to eight neighbours in 2025/26: Botswana, the Democratic Republic of Congo, Eswatini, Lesotho, Mozambique, Namibia, Zambia and Zimbabwe. In 2024/25 it sold 14,532GWh into the Southern African Power Pool and bought 7,570GWh, with sales up 40% year on year. Bilateral deals dominate regional trade, and competitive bidding accounts for about 7% of pool transactions. At roughly 63.4GW, South Africa’s generation capacity dwarfs Angola’s 7.6GW, the region’s next largest.
The surplus is new. South Africa has gone more than four months without load-shedding, and Ramokgopa has said generation now exceeds demand at times. The recovery of Medupi power station, which was offline after a generator stator explosion in August 2021, has added about 800MW. Breakdowns at Matimba caused the most recent outages.
Zambia’s position runs the other way. Drought cut hydropower at Kariba from 2024, forcing state utility Zesco to ration supply to households and copper mines. Zambia is Africa’s second-largest copper producer, which makes reliable power central to its economy and to demand for any South African exports.
The underlying constraint is transmission. Most new wind and solar capacity sits in the Northern, Eastern and Western Cape, where the grid is already congested. Eskom sought approval from the National Energy Regulator of South Africa for a curtailment framework covering all grid-connected renewable plants, with congestion curtailment expected from 2026. The government’s transmission plan targets 14,500km of new lines. The first request for proposals under the independent transmission programme has slipped to the second quarter of 2027, from a third-quarter 2026 target.
Ramokgopa cautioned against connecting renewables faster than the system can handle. He pointed to the blackout that hit Spain and Portugal in April 2025 as a sign of what can go wrong. He set out 11 trends for the sector, including the need for storage and grid flexibility, and called low-cost renewables the anchor of new generation.
Selling power to Zambia would depend on grid links through Zimbabwe or Botswana and on Zesco’s ability to pay. Zesco’s debts to regional suppliers have weighed on past trade. The South African Wholesale Electricity Market, due to launch in April, is expected to change how surplus power is priced and traded.