In South Africa, electric geysers are a fixture in most households, offering a significant opportunity for larger complexes, estates, and retirement villages.
Once regarded only as a major contributor to electricity costs, geysers can now serve as practical, low-cost energy management tool—especially with the arrival of Eskom’s evolving tariffs and the widespread adoption of rooftop solar power.
Since load shedding began in 2007, South Africans have steadily adapted to an unreliable and increasingly expensive grid. Households have upgraded to energy-efficient lighting, converted electric stoves to gas, replaced ovens with air fryers and installed alternative space heating solutions like closed-combustion wood stoves. These incremental improvements have helped improve resilience and curb electricity costs.
In larger residential developments, where scores or even hundreds of units rely on electric geysers, water heating can account for over 50% of electricity consumption. This makes tariff optimisation a top priority for reducing operating costs and improving energy resilience.
Eskom’s Homeflex tariff, now available to Eskom-direct residential customers, targets households with grid-tied solar PV systems (where it is mandatory) and is open to other households that choose to opt in.
This Time-of-Use (TOU) tariff varies electricity rates depending on the time of day: lower during off-peak periods—like midday or late at night—and significantly higher during peak times, especially evenings.
In winter (June to August), peak rates can be as much as six times higher than off-peak rates. This presents a major opportunity for savings for those able to shift electricity use to cheaper periods.
While Homeflex applies to individual Eskom-direct units, body corporates and estate managers can adopt similar TOU-aligned strategies for municipally supplied complexes. Paired with smart meters, batteries and solar systems, these strategies can help reduce electricity costs across the board.
Electric geysers can act as simple thermal storage systems. By heating water during low-cost periods—whether overnight or during solar generation peaks—estates and complexes can store energy as hot water and avoid heating during expensive peak-rate hours.
A standard 150L or 200L geyser with insulation typically loses just 1–2°C of heat per hour. Water heated to 60°C during the day or overnight will often remain hot well into the evening. With smart control or even basic timers across units, estate managers can align geyser usage to optimise price and performance.
For estates exploring gas geysers or heat pumps, the economics often don’t stack up. LPG prices can be volatile and supply logistics can become complex—and costly—when scaled across multiple households.
Heat pumps, while energy-efficient in operation, require a high upfront investment and ongoing maintenance. These systems may make sense for new developments but are harder to justify where electric geysers are already installed and working reliably.
By comparison, electric geysers are simple to maintain. Common issues like thermostat or element failure are inexpensive and easy to fix, and if a geyser fails entirely, it’s typically covered by insurance. Optimising what’s already in place is often the most cost-effective path forward.
Coordinated geyser management in complexes, estates, and retirement villages doesn’t just reduce electricity bills - it also supports broader energy resilience.
By synchronising geyser heating to off-peak periods across dozens or hundreds of units, these developments can act as a collective thermal battery. This flattens peak demand; eases pressure on the national grid and helps communities weather load shedding more effectively.
Add smart meters, communal solar PV systems, battery storage, and backup generators, and these residential communities can operate as efficient microgrids.
Estate managers and body corporates can lead this shift by installing geyser smart controllers across units-an affordable and scalable upgrade. Aligning usage with Homeflex schedules for Eskom-direct homes, or TOU principles in municipal areas, helps optimise consumption.
Where applicable, midday solar generation can handle much of the water heating at minimal marginal cost. Eskom’s ongoing smart meter rollout supports this transition, and potential tax incentives or subsidies for energy-saving upgrades could help offset upfront investments.
Centralised coordination ensures consistency, maximises savings, and delivers long-term benefits for all residents.
For complexes, estates, and retirement villages, electric geysers are no longer just an unavoidable energy load, they’re an opportunity. Whether individual homes use Homeflex, or body corporates implement centralised TOU strategies, optimising existing geysers delivers immediate value.
This approach cuts electricity bills, improves reliability, and contributes to a more sustainable, flexible energy future.
According to Allan Ridley, Decentral Energy’s battery storage and energy efficiency expert
Centralised load management of geysers, without any discernible loss of comfort for residents, is a game changer for energy efficiency in complexes. In effect South Africa has a huge, distributed thermal storage battery already installed – getting that battery working could have the same benefit as adding another power station to the grid
Want to explore what Solar PV combined with coordinated geyser control could do for your complex or estate? Contact Decentral Energy for tailored energy solutions that work for your residential community.
