By Jon Kornik
South Africa is currently considering options to manage household energy demand that would penalise those who want to be part of the solution. All this while better, tried-and-tested alternatives are readily available.
By now, South Africans are well accustomed to the most extreme form of demand management. Load shedding, which started the better part of two decades ago and was estimated by the CSIR to cost the economy more than R1 trillion in 2023 alone, has (until recently) been necessary to bring electricity demand back into line with available supply.
With the veil of load shedding lifted, electricity demand is consistently higher, exposing our ageing and undersized distribution infrastructure. To prevent grid failures, municipalities and Eskom are reducing supply to homes in affected areas with rotational “load reduction” – effectively load shedding by another name, but in a more isolated area.
But we can also limit the severity of rolling blackouts by managing demand in other ways. Encouragingly, there is a renewed push to do so by policymakers.
The problem is that many of the interventions being considered are outdated and are still far too heavy-handed.
Several of them focus on controlling household geysers and other energy-hungry appliances – turning them off during peak hours in the mornings and evenings when the grid is usually most constrained.
This may sound reasonable on the face of it, but most of the technologies – such as ripple controllers and load-limiting smart meters – will have negative impacts on households and the grid.
Ripple controllers, which saw their heyday roughly half a century ago, allow municipalities or Eskom to switch off and on large fleets of geysers on command.
Load-limiting smart meters, on the other hand, restrict the supply of electricity to households to a level where they can keep the lights and their TVs on, but cannot cook food or run their geysers.
While these technologies help to plug the energy supply gap, they come with their own complications and inconveniences.
For example, our calculations show that aside from not being able to prepare dinner or boil the kettle, most households will have to put up with cold showers 15% of the time in winter.
At the same time, these technologies bring fresh challenges for municipalities and grid operators – with knock-on consequences for households, once again.
This is because turning an entire fleet of geysers back on at the same time causes severe spikes in power demand, which can both drive up costs and damage substations and other network infrastructure.
To deal with this, these technologies typically turn geysers back on in batches – effectively extending load shedding, especially for those unlucky enough to be in one of the later groups.
There are better ways forward.
A 30-month study in South Africa demonstrated, unequivocally, that smart water heater management systems can overcome these problems – while also saving households money.
Under Project Smart Geyser – which was supported by German development agency GIZ, clean energy financing facility EEP Africa, the University of Cape Town, and others – 500 electric water heaters were fitted with devices developed by energy technology company Plentify.
Enabled by artificial intelligence, these devices, called HotBots, shifted each geyser’s power consumption away from peak hours and towards the most optimal times for both the grid and the participating household.
HotBots effectively adapted to the hot water consumption patterns of each home. They preheated geysers before load reduction events if necessary – but still supplied electricity during those events for the small proportion of homes that needed it to ensure they had a steady supply of hot water.
The study found that the devices reduced geysers’ average peak-period energy use by up to 80%, thereby helping to flatten demand surges on the grid. Importantly, they did so without compromising on hot water availability.
Our analysis shows that if HotBots were installed in a quarter of Cape Town’s homes, as an example, we could reduce 20 hours of morning and evening Stage 6 blackouts per month in the city.
Households would also benefit from higher disposable incomes thanks to reduced electricity bills. During the pilot project, the devices improved each geyser’s overall energy efficiency by 24% by intelligently switching them off when they did not need to be consuming energy.
Aside from helping to fight load shedding in the near term, HotBots are programmed to draw power from solar systems during the day. This more than doubles the amount of solar that can feasibly be installed on each household rooftop, which could meaningfully boost the country’s generating capacity.
This highly successful study has confirmed that South Africa has the tools and expertise needed to create a smarter, more efficient electricity system, where individuals are truly incentivised to be part of the solution.
While some municipalities are doubling down on ripple controllers and service-limiting smart meters, others are actively embracing new technologies as they seek to end power cuts while also creating a cleaner, more affordable, and more resilient power system.
Jon Kornik is the CEO of Plentify
BUSINESS REPORT