Eskom's tariff modernisation requires large power users to adapt strategically. Based on the Cost-to-Serve study, the core shifts include changes to time-of-use hours and the introduction of a fixed Generation Capacity Charge. To minimise cost, large power users must invest in efficiency and actively shift consumption to the new off-peak windows, using data to raise their load factors.
Eskom's revisions respond to declining sales, rising costs and the growing adoption of alternative energy. The old structure, which recovered fixed costs mainly through kWh charges, is no longer sustainable. The changes are founded on the Cost-to-Serve study, which ensures charges reflect the actual fixed and variable costs of supply, splitting time-of-use costs into variable energy and fixed capacity across peak, standard and off-peak periods.
A key driver for large power users is raising the load factor, the ratio of average demand to peak demand. Eskom explicitly targets customers with high peak consumption. Increasing the load factor through strategic load shifting is the most effective defence against rising time-of-use peak charges and the new Generation Capacity Charge.
The time-of-use hours, largely unchanged since 2005, are being revised to match current system needs. Proposed changes include a longer three-hour evening peak, a shorter two-hour morning peak, and a new two-hour Standard period on Sunday evenings. Operating schedules that were safe in Standard periods may now fall into more expensive windows unless adjusted.
The strategic response is optimised load shifting: use real-time monitoring to move high-energy processes precisely into the new off-peak hours, invest in efficiency to lower baseline demand, and keep maximum demand controlled to limit exposure to the capacity charge.
Declining sales, rising costs and more alternative energy have made the old structure, which recovered fixed costs mainly through kWh charges, unsustainable. The revisions, based on the Cost-to-Serve study, make charges reflect the actual fixed and variable costs of supply.
A fixed capacity charge that reflects the cost of generation capacity. Combined with revised time-of-use periods, it rewards a flatter, higher load factor and penalises heavy peak consumption.
Proposed changes include extending the evening peak to three hours, reducing the morning peak to two hours, and adding a two-hour Standard period on Sunday evenings, so schedules that were safe may now fall into pricier windows.
Increase load factor through strategic load shifting, using real-time monitoring to move high-energy processes into the new off-peak hours, which is the most effective defence against rising peak and capacity charges.