Truth about Eskom’s plan to switch off your geyser

Eskom’s smart meter rollout will not give the utility control over households’ geysers or other appliances but will enable the company to continue providing lower amounts of power during load-shedding.

The idea that Eskom wants to control people’s geysers likely stems from comments made by electricity minister Kgosientsho Ramokgopa in an interview with eNCA in June 2023.

Ramokgopa said that South Africans turning off their geysers could contribute to fixing load-shedding.

The government estimated that geysers in the country consume around 3,500MW of electricity and aimed to reduce this by a minimum of 1,000MW.

Ramokgopa advanced the idea that this reduction would be achieved through smart meters installed in Eskom customers’ homes.

Eskom aims to replace all 6.9 million meters used by its direct customers with smart meters, at an estimated cost of R15 billion.

However, the power utility has no intention of switching off high-demand appliances as a regular practice. Smart meters also do not give Eskom the technical capability for such precise control.

Instead, they enable Eskom to implement a practice called load limiting.

Households participating in this programme are required to lower their maximum current usage from the regular 60 or 80 amps to 10 amps for the duration of their area’s scheduled power cuts.

This demand-side management mechanism is similar to load curtailment.

Load curtailment allows large power users, such as industrial customers or even large estates and small towns, to avoid load shedding by manually limiting their demand by a certain percentage.

Without load limiting or load curtailment, a household or businesses without their own backup would have been without any power.

Like having a small backup system — without paying extra

Under load-limiting, the amount of power a household can consume is similar to that of a small backup power system.

Customers can draw up to 2.3kW under stage 1 to stage 4 load-shedding. That works out to 4.6kWh over a two-hour load-shedding slot.

For reference, an entry-level backup battery system typically has between 3kWh and 5kWh of power.

That is enough capacity to power lights, TVs, laptops, routers, fridges, and small microwaves.

Energy-efficient air fryers also consume between 1kW and 2kW, so you could even cook food during this period if you use other appliances sparingly.

There are also energy-efficient geyser elements that consume 1kW or 2kW that could still run during load limiting.

Eskom only switches off a load-limited customer’s power for 30 minutes after they continue exceeding the 10A allowance after four warnings.

When power is restored, the customer will again be load-limited if they keep within their allowance.

When no load-shedding is implemented, customers can use the full 60A or 80A current supported by their connection, as normal.

The way Eskom’s smart meters and load limiting function reveal that there was no plan to switch off people’s geysers remotely.

Instead, households are required to manage their loads so that they draw less than 10A at peak within their load-shedding slot.

This may include switching off a geyser with an element that pulls more than the allowed load.

That does not mean a household will have cold water, however. Geysers are designed to retain heat for a long time. They do not need to run consistently.

A 200-litre geyser only needs about one hour of heating time to go over 50°C from room temperature.

Showering consumes between about 10 and 20 litres of water per minute. Unless you plan to hurt yourself, this will consist of a mix of hot and cold water.

From a one-hour heating session, at least three or four people can take a 5-minute shower without running out of hot water.

Load limiting plugging a revenue drainer

Implementing either load limiting or load curtailment during periods in which Eskom has sufficient generation capacity would not only be an overreach on the utility’s part, it would also cost it valuable revenue.

Eskom can hardly afford revenue declining as demand for its product has gone into freefall due to more people switching to self-generation.

Load limiting ensures that the power utility can continue collecting some revenue from electricity usage during load-shedding.

Eskom has already rolled out 400,000 smart meters and is expanding its load-limiting programme from a pilot in Fourways to Buccleuch, Kelvin, Paulshof, Marlboro, Sunninghill and Waterfall.

It also told MyBroadband it wanted to introduce the mechanism to all provinces by the end of February 2024.

However, it has not responded to MyBroadband’s queries on the progress of this plan.