Cresco Warns of Potential Energy Security Risk if Diesel Supply for OCGT Is Constrained

Why It Matters

A diesel supply shock would jeopardize grid reliability and increase load‑shedding risk, threatening South Africa’s industrial competitiveness. Diversifying to renewables and storage offers a long‑term hedge against fuel volatility and geopolitical disruptions.

Key Takeaways

• Eskom may need Stage 1/2 load shedding if diesel supply tight
• Diesel use can rise to 30% of national supply during peak demand
• 17.7 GW of coal capacity slated for retirement by 2035
• Microgrids with solar and batteries can cut diesel reliance >90%
• Lack of BESS and grid‑forming inverters risks renewable‑fuel imbalance

Pulse Analysis

South Africa’s power landscape is at a crossroads. Eskom’s four open‑cycle gas turbine (OCGT) peaker plants, which run on diesel, currently consume a modest 3‑10% of the country’s refined diesel. However, during peak periods that figure can surge to 20‑30%, a volume that strains an import chain already vulnerable because 57% of diesel arrives via the geopolitically sensitive Strait of Hormuz and only two of five local refineries are operational. This dependency creates a clear energy‑security risk, especially as Eskom’s coal fleet shrinks.

Compounding the diesel dilemma, Cresco’s modeling shows that the scheduled retirement of 17.7 GW of coal capacity by 2035—about 40% of the grid—will leave a sizable generation gap. Without adequate replacements such as liquefied natural gas, nuclear, or, crucially, battery‑energy‑storage systems (BESS) and grid‑forming inverters, the grid will experience pronounced deficits during early‑morning and evening peaks. The renewable rollout, while essential, lacks the dispatchable flexibility needed to balance supply and demand, raising the probability of load‑shedding if diesel supplies falter.

The strategic answer lies in decentralized resilience. Renewable microgrids that pair oversized solar arrays with high‑capacity batteries can slash diesel consumption for critical loads by more than 90%, while grid‑forming inverters provide black‑start and islanding capabilities. For commercial and industrial users, such on‑site solutions not only hedge against fuel price volatility and geopolitical shocks but also lower logistics costs. At the national level, scaling BESS and incentivizing microgrid adoption will reduce reliance on imported diesel, safeguard economic productivity, and create a more stable, low‑carbon power system for South Africa’s future.