Plenty of households used less electricity this year and still opened a bigger bill. That's not a meter fault — it's a real, regulator-approved shift in how South African electricity is priced, and it changes the maths on whether solar is worth it.
Who actually sets the price
NERSA (the National Energy Regulator of South Africa) approves Eskom's tariffs for customers who buy directly from Eskom. Municipalities like the City of Cape Town buy bulk power from Eskom at a NERSA-approved rate, then set their own retail tariffs — which NERSA also has to sign off on.
The increases, as approved
NERSA approved a 12.74% increase for Eskom's direct customers from 1 April 2025, and municipalities buying bulk power got an 11.32% increase from 1 July 2025. The following year brought further increases: 8.76% for Eskom direct customers from 1 April 2026, and 9.01% for municipal bulk buyers from 1 July 2026. The City of Cape Town's own residential tariffs for 2026/27 show category increases of between 5.92% and 8.65%.
NERSA-approved increases. Sources: IOL, Mail & Guardian, City of Cape Town.
Why the fixed charge matters more than the headline number
NERSA approved a restructuring of Eskom's tariffs in February 2025 that reduces the variable, time-of-use energy charge and phases in a new fixed "Generation Capacity Charge" over three years from 1 April 2025 — billed monthly regardless of how much grid electricity you actually draw. That restructuring is also why NERSA opened a formal market inquiry in September 2025 into rising fixed and capacity charges, after complaints from consumers, businesses and municipalities about affordability and transparency.
Solar industry commentary picked up on exactly this shift: as reported by Energize magazine, "Eskom's retail tariff plan has progressively increased the share of costs recovered through fixed components such as service charges, administration fees and generation capacity charges" — which means a bill stays higher than expected "regardless of electricity usage levels," even for a home generating a good share of its own power.
Cape Town's own structure
The City of Cape Town runs four residential tariffs — Lifeline, Domestic, Home User and an optional Time-of-Use tariff — and the two most common (Domestic and Home User) use an inclining block structure: a lower rate for the first 600kWh a month, and a higher rate above that, on top of a fixed monthly Services & Wires Charge. Full detail is on the City's own tariff page.
None of this means solar stops making sense — it means the part of the bill solar can't touch (the fixed charge) is growing, so a proper assessment has to be based on your actual usage pattern and tariff, not a rule of thumb.