For years, the sales pitch for a battery was done by Eskom. Power goes off, your home or business stays on. It was compelling.
By Lance Dickerson, MD of REVOV
The grid is behaving very differently today, thanks to improvements at Eskom and the thousands of privately funded solar installations that have reduced demand during daylight hours. In early October, Eskom said South Africa had recorded 504 consecutive days without load shedding.
That is excellent news, and long may it last. But if load shedding has stopped, what do we use our batteries for now? We bought batteries under pressure because the alternative was to sit in the dark or lose productive time. Backup was always only one of the jobs a battery could do.
Electricity is not cheap
The obvious place to start is the electricity bill. Eskom’s average electricity price for customers it supplies directly increased by 8.76% for 2026/27. For anyone who already has a battery and inverter, that increase is another reason to look at how the system is being used.
For customers on Eskom’s time-of-use tariffs, electricity costs differ between peak, standard, and off-peak periods. Where there is a meaningful difference between the rates, stored energy can cover part of the more expensive periods.
For many owners, the biggest investment has already been made. They have a battery, an inverter and, in some cases, solar panels. The question now is whether that equipment is being used effectively enough to help reduce their electricity costs.
Businesses need a different calculation
Some businesses pay more for electricity when their demand is at its highest. A battery can take on some of that load instead of drawing all the power from the grid, which could help reduce those charges. How much a business can save will depend on its tariff.
This will not suit every business. A workshop and a cold-storage facility have very different electricity demands, so the potential savings need to be assessed for each site. For some businesses, managing those costs could give the battery a useful job every day.
We have talked about load shifting and peak shaving for years. What customers want to know now is whether those capabilities will reduce their electricity bills. That requires a proper look at the tariff and consumption patterns, followed by checking the electricity bills to see whether the changes have delivered the expected savings.
Use the solar you already paid for
A home or business can have more solar power than it needs in the middle of the day and still find itself buying electricity from the grid that evening. A battery allows some of that surplus to be stored for later, reducing how much electricity needs to be bought once the panels stop producing.
The first question is whether the existing system is configured to do it. If a large share of the battery is permanently held in reserve for load shedding, an installer can assess whether that still makes sense. Businesses and households may want to keep some backup while making more capacity available for normal daily use.
Using the battery more often also raises questions about how that affects its lifespan. REVOV’s second-life LFP cells were selected in part for their ability to handle demanding charge and discharge cycles. Even so, owners need to understand the battery’s operating limits and make sure it is configured correctly for the application.
The solar array deserves a look as well. If the panels are not reliably replenishing the battery before evening, the answer may be more PV rather than a new storage system.
Your geyser is a battery too
On a sunny day, the battery could be full by lunchtime, with hours of sunshine still to come. Some solar installations have no battery at all. If the property cannot use the extra electricity, the inverter may cut back production or feed it into the grid. And depending on the municipality, the owner might get next to nothing for it.
The humble geyser is one of the best places to put that energy. Heating water is one of the largest single loads in many homes, and a well-insulated tank keeps water hot for hours. Heating 150 litres of water by 40°C takes roughly 7 kWh of electricity, before allowing for heat losses. That’s a substantial amount of energy that could come from solar panels during the day.
Heating water during the sunniest hours can reduce the electricity bought from the grid in the morning or evening. A timer is one option, although a controller that responds to surplus solar production can make better use of the electricity available. Insulating the geyser and its pipes also helps retain heat. A qualified installer or electrician can advise on the appropriate setup.
Adding storage to a solar-only system
Homes and businesses that installed solar panels without batteries can use the electricity they generate during daylight hours. Once the sun sets, however, they still depend on the grid for whatever power they need.
Adding a battery means solar power generated during the day can still be used after sunset. For a household that buys a lot of electricity in the evening, this could make a noticeable difference to the monthly bill. The panels must produce enough surplus power to charge the battery, though, and the savings need to justify the cost of adding storage.
It is also worth checking what the existing inverter can handle. Some solar-only systems can accommodate a battery without major changes, while others will need a hybrid inverter or an AC-coupled setup. A reputable installer can look at the equipment already in place, check how much electricity the household uses and work out whether adding storage makes financial sense.
Keep the backup, use the battery
Local outages haven’t disappeared, and in some areas the distribution infrastructure remains in poor condition. Any changes to how a battery is used must still leave enough capacity to keep essential equipment running when the power fails.
Owners who installed their systems during the worst of load shedding should have a reputable installer review whether those settings still make sense. Eskom is doing a better job of keeping the lights on, but it’s still charging us plenty for the privilege. A properly configured battery could help with that, while remaining ready for the next power cut.