South Africa has recorded a landmark 160 days with no load-shedding, the longest period in over four years, and is on track for a load-shedding free winter. However, maintaining future grid stability will require a doubling down on wind investment as well as higher spending on transmission infrastructure, says local renewable energy developer Red Cap.
Two factors contributed to this milestone: greater availability of baseload power, as well as the new supply contributed by private wind developers.
As of August 2024, Eskom’s available generation capacity reached over 35 000MW, which exceeded peak demand by more than 3 000MW.
Prior to this, there were many instances where load shedding would have been necessary were it not for 3 400MW of wind energy, which remained available to the grid even when baseload power was insufficient.
Clearly, wind energy has earned its place in South Africa’s energy mix, alongside baseload generation and solar power, says Mark Tanton, Red Cap CEO and co-founder.
“Wind contributes less than 3% of South Africa’s energy supply and significantly increasing this amount will be hugely beneficial,” he says. “To do that, we must finalise the curtailment policy and expand the transmission infrastructure.”
South Africa has the largest wind power installation in Africa, but notably lags behind other regions. In Europe, wind provides 20% of the overall energy mix, with plans to increase wind’s contribution to over 50% by 2050. Already, 58% of Denmark’s power supply comes from wind.
Eskom’s peak demand periods in the morning and evening take place outside daylight hours, when solar power is unavailable, but while wind power is still being generated. As a result, wind is uniquely placed to mitigate load shedding. Additionally, with wind generation dispersed across the country, there is a robust and distributed network of energy sources, supporting a predictable supply and a more resilient grid.
“Wind produces electricity at various times across the country, because wind strength varies. So, it could be extremely windy in the Northern Cape, for example, and it’s not as windy in the Eastern Cape, but there is an average production rate than can be relied on for availability,” Tanton explains. “The more you diversify your energy mix, the greater the energy security and the lower the risk of load shedding.”
A diversified energy mix relies on sufficient infrastructure. Eskom’s transmission lines are near or at capacity in many regions, which constrains the amount of renewable energy available to the grid. In practical terms, this means that renewable energy projects have uncertain access to the electricity grid.
The National Energy Regulator (NERSA) is expected to approve policy which would stipulate a maximum amount of curtailment (10%) for these projects and compensate developers when they are able to generate power, but unable to export it into the grid. Eskom estimates that initially a further 3GW of wind power could be connected to the grid in this way.
Grid capacity has emerged as the leading constraint on renewable power projects in South Africa. Already, 23 wind projects put forward under Bid Window 6 of the Renewable Energy Independent Power Producer Procurement Programme were unable to be awarded, due to a lack of grid capacity.
Red Cap is proactively developing grid infrastructure to connect their own wind projects, including a 116km powerline for the Impofu wind farm project, which is the longest privately permitted powerline for any renewable energy project in the country.
But developing transmission infrastructure at scale requires a partnership between the private sector and government. “Accelerating investment in transmission infrastructure through private involvement will be helpful – if it avoids inadvertently creating micro monopolies who control access to the grid,” says Tanton.
The renewable energy landscape has changed substantially over the last decade, with private developers coming to the fore, and more agreements between private developers and large energy users seeking to reduce their carbon footprint. Ultimately, this makes for a richer, and more robust, energy sector, which serves South Africa’s overall energy security.