Wietze Post: Wright's Law kicking in- solar, battery prices collapsing

Key topics:Solar and battery costs plunge following Wright’s LawEskom tariffs rise, driving shift to self-generationRapid adoption accelerates South Africa’s energy transition.Sign up for your early morning brew of the BizNews Insider to keep you up to speed with the content that matters. The newsletter will land in your inbox every morning on weekdays. Register here.Support South Africa's bastion of independent journalism, offering balanced insights on investments, business, and the political economy, by joining BizNews Premium. Register here.If you prefer WhatsApp for updates, sign up to the BizNews channel here..By Ir. Wietze Post.Part three of a six-part series by Ir. Wietze Post Part Two may be found here: XXX.Wietze Post (Part 2) – The solar duck curve: Nemesis to coal and nuclear plants.The primary driver of Eskom’s accelerating decline is cost. Eskom is raising its energy prices, while the cost of solar power equipment is going down.Solar panels and lithium-ion battery costs have closely followed Wright’s Law. They keep getting cheaper as more such equipment is sold.Each time global cumulative sales double, solar module prices drop by around 20%. This is based on data from Our World in Data (2025) and IRENA. Prices have dropped more than 90% in the last decade alone.Lithium-ion battery pack prices dropped another 8% in 2025 to a record low of $108/kWh (average). Stationary storage systems now cost $70 per kWh. That's a 45% drop in just one year (BloombergNEF 2025 Lithium-Ion Battery Price Survey, December 2025).Right now, equipment costs (in USD) are about 20% of what they were ten years ago, after adjusting for inflation.Every new solar and battery installation helps lower costs and boosts appeal. This reinforces the learning curve effect.Meanwhile, Eskom continues to raise tariffs.This feeds an accelerating cycle. More and more South Africans are meeting their energy needs without help from Eskom or the government. They're doing this proactively and at an increasing pace..Other topics in this series:.Next: Duck Curves, Day-Night Inversion and the Coming Zero-Demand Hours (Part 4 of 6)Eskom’s daily demand curve has permanently transformed. This change shows that consumers need less energy from Eskom. And they need less every year. Duck curves now frequently appear in Eskom’s supply patterns. Other topics:- The Numbers Don’t Lie – Eskom’s Demand is Collapsing – The Data (Part 1 of 6)South Africa is steadily moving away from Eskom, as discussed on 7 and 14 February 2025. This series updates the trends and forecasts I covered in my earlier articles. It focuses on the latest changes and insights.- The S-Curve is Here – And Eskom is on the Wrong Side of It (Part 2 of 6)New technologies usually follow an S-curve. Their adoption starts slowly, then quickly picks up speed. In South Africa, solar and battery technologies have entered a phase of rapid adoption. Meanwhile, the demand for Eskom’s electricity is following a downward S-curve.- What Eskom, IPPs and Big Business Must Do Now (Before 2029) (Part 5 of 6)- Your Electricity Costs from 2026 to 2030 – The Great Divide (Part 6 of 6)How much will your monthly electricity cost increase between now and 2030?

Wietze Post: Wright's Law kicking in- solar, battery prices collapsing

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