Best ways to fight load reduction in South Africa

South Africans haven’t been subjected to load-shedding since 26 March 2024, but many areas of the country still experience load reduction, which hits some communities harder than stage 6 load-shedding.

Residents of these communities have several options to keep their electronics powered during load reduction, including solar power installations, portable power stations, inverter trolleys, and uninterruptible power supplies (UPSes).

In late August 2024, Eskom spokesperson Daphne Mokwena explained that load reduction occurs during peak demand hours — primarily in the mornings and evenings — with most bouts lasting two hours.

“However, in certain areas, peak hours where we are seeing overloading becomes extended to about five hours. In other areas, it’s four hours both in the mornings and the evenings,” she said.

South African residents experienced average outages of 10 hours per day under stage 6 load-shedding.

Many South African residents suffering from load reduction are likely looking for relief from the scheduled power outages. The most obvious solution to many is a solar power system.

Solar power provides reliable relief from load-shedding and load reduction. Photovoltaic solar panels provide power during the day, and batteries store excess energy for use at night.

Depending on their needs, South African homeowners can choose to install a grid-tied solar power system or an entirely off-grid setup.

Grid-tied systems will rely on solar generation to power household electronics and appliances and charge batteries while there is enough sun to meet these needs.

During extended cloudy periods, or when solar energy isn’t sufficient to power the household, a grid-tied system can pull power your local power grid to make up the difference.

A recent MyBroadband analysis revealed that a grid-tied system can cost South African households as little as R143,000.

Prices vary on how much a household consumes each month. This figure relates to a household that consumes 450kWh of electricity monthly.

As the name suggests, off-grid systems can’t pull power from local power grids when there isn’t sufficient solar capacity for a household’s needs.

These systems must be oversized to account for extended periods of limited sunlight.

According to AWPower managing director Christiaan Hattingh, an off-grid system must be three or four times larger than a grid-tied system to account for such periods.

This can make off-grid systems significantly more expensive than the grid-tied alternative, and Hattingh also recommended a fuel-based generator, further adding to the cost.

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Portable power stations, inverter trolleys, and inverter installations

Backup power products such as inverter trolleys and portable power stations can provide an affordable means of staying connected and entertained during load-shedding and load reduction outages.

They essentially combine the components of a home battery and inverter installation into a portable form that users can charge off of mains power.

They feature standard sockets to connect an extension cable, multiplug, or directly plug in your electronic equipment.

As with battery and inverter installations, it is critical to consider the type of battery, its capacity, and the maximum output of an inverter trolley or portable power station before buying one.

The inverter’s output determines how much power can be drawn at once. For example, a 3kW inverter will overload if connected devices draw more than 3,000W simultaneously.

To prevent overloading, it is advisable not to use power-hungry appliances like kettles or other devices with elements through an inverter trolley or portable power station.

The best approach is to determine which electronics you want to use during scheduled power outages and their power draw before deciding on a backup.

Battery type and capacity determine how long you can power these electronic devices.

Fortunately, this is relatively straightforward to calculate. You can add the total power draw of the appliances you want to keep powered and then multiply the result by the number of hours in a load reduction session to determine how many kWh the battery must provide.

However, when considering the depth of discharge, it is essential to differentiate between total capacity and the battery’s usable capacity.

Lead-acid batteries degrade rapidly when discharged below 50%, meaning you would have to double your battery capacity requirements.

However, lithium-ion batteries perform well when discharged to as low as 10%. They also offer significantly more recharge cycles than lead-acid batteries and won’t need replacing as often.

For homeowners, installing an inverter and battery on your property is also a relatively affordable option compared to a solar power installation or running a generator.

However, the installation costs make inverter and battery installations more expensive than trolleys and portable power stations.

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Uninterruptible power supply (UPS)

UPSes are generally not designed to keep electrical equipment powered for the entire duration of planned power outages.

However, they offer users a short but reliable window of backup power to save their work and safely shut down their electrical equipment.

They also act as surge protectors to prevent damage to electronics when power is restored after a bout of load shedding or load reduction.

It is important to note that running a UPS to keep electronics powered for extended periods can significantly deplete their capacities.

It is possible to get large UPS units that can keep electronics up and running for hours. For home users, these become a similar solution to power trollies.