Eskom’s silent saviour

Private solar power is quietly playing a substantial part in alleviating load-shedding, according to recent feedback from the National Transmission Company of South Africa (NTCSA).

The company was spun off from Eskom to operate South Africa’s long-distance transmission network in a demonopolised electricity market with more private power producers.

The NTCSA’s divisions include the System Operator, which is responsible for managing electricity supply and demand and announcing the implementation of load-shedding.

System Operator general manager Isabel Fick previously explained that so-called “behind-the-meter” solar power was taking significant strain off Eskom’s peaking power stations during the day.

With households and businesses relying more on self-generated power when the sun is shining, Eskom was able to save its diesel and water reserves to tap into its emergency generators in peak periods.

As of April 2025, the NTCSA estimated there was roughly 6,178MW of private rooftop solar in the country.

When operating at peak capacity, this is sufficient to stave off six stages of load-shedding.

In more recent feedback, the NTCSA explained how the weather in early 2025 had reduced production from these users and contributed to the implementation of load-shedding on several occasions.

“The northern and central parts of South Africa experienced long periods of overcast conditions, particularly in Gauteng, where much of the behind-the-meter PV is installed,” the NTCSA said.

It explained that these prolonged periods forced electricity users to return to the grid during the day.

In turn, Eskom had to supplement the generation supply with pumped storage dams and open-cycle gas turbines.

“Due to the higher usage of these generators from the beginning of a week, the fuel sources began to deplete towards the end of the week,” the NTCSA said.

“This is clearly seen by the number of weekend load-shedding events that were needed to reduce demand from the grid in order to replenish the dam and diesel levels.”

Many solar power users in South Africa also have batteries charged with solar energy that they use during peak demand periods.

In this way, private solar power plays a greater role in South Africa than in other countries, where backup is often less important than savings.

“The impact of overcast weather is felt significantly when the overcast conditions persist for more than a day and battery storage is depleted,” the NTCSA said.

Eskom casts solar in negative light — while government wants to take credit for it

The fact that the need to implement load-shedding can be traced back to weather conditions affecting private solar production shows that self-generation has meaningfully reduced the strain on Eskom’s grid.

However, Eskom has largely failed to acknowledge the positive contribution.

The impact has often been framed in a negative light, with Eskom regularly saying that the increased use of solar resulted in people using Eskom like a battery.

It has used this as a justification for why it needs to increase fixed electricity charges under its Retail Tariff Plan.

Electricity minister Kgosientsho Ramokgopa has also rejected the idea that private solar generators were doing Eskom a “favour” by helping to reduce load-shedding.

In Eskom’s recent winter load-shedding outlook briefing, he discouraged binarising private solar’s contribution against the power utility’s own improvements.

Ramokgopa said private solar was part of the “aggregate system designed to perform in that fashion.”

He also strongly implied that President Cyril Ramaphosa’s Energy Action Plan deserved credit for the increased role of private solar.

Certain incentives implemented during Ramaphosa’s tenure, including abolishing the need for large installations to be licensed, have certainly contributed to the increased uptake of solar energy.

Ramaphosa’s government also offered tax incentives for households and businesses investing in solar power.

However, the tax rebate for households buying solar panels was widely criticised as insufficient.

Many solar power installers also said it played a very small part in people’s decision to invest in self-generation.

The reality is that many individuals and businesses had installed solar and backup power long before these incentives were introduced — as it was the best way to endure increasingly severe power cuts.

They would not have needed to do so in the first place had the government not failed to listen to energy experts’ calls to build more capacity nearly a decade before load-shedding started.

It was only during the worst years of load-shedding that the government finally acted, often on the private sector’s recommendations, to relax regulations that made private self-generation difficult.