The Nedbank Senseable Geyser programme, developed by Sensor Networks, is introducing a new method for managing household energy and insurance risks in South Africa. The initiative connects electric water heaters—commonly called geysers—to monitoring systems that track usage, automatically shut off leaks, and allow users to control their devices through a mobile application.
Since its launch 18 months ago, the programme has expanded to include roughly 10,000 connected geysers. These systems have intercepted nearly 2,000 leak events before they caused significant damage. Sensor Networks estimates that these interventions could have prevented 800–1,000 severe water-damage claims, though the company notes that this projection relies on historical insurance patterns rather than direct verification.
The technology pairs hardware with an app that enables households to adjust heating schedules, monitor consumption, and receive alerts. Sensor Networks calculates potential savings by comparing real-time energy use against a baseline: a conventional geyser set to 65°C without scheduling. With South Africa’s current electricity tariff of R3.20 per kilowatt-hour, the company estimates households save an average of R402 per month, equivalent to roughly 125.6 kWh less consumption.
How much households really save
Nedbank covers the R99 monthly service fee for policyholders, leaving customers with a net benefit of about R303 per month. However, actual savings depend on how households manage their geysers and their electricity tariffs. A family already optimising heating schedules may see minimal reduction, while one that previously left their geyser running constantly could achieve greater savings.
The insurance implications are equally significant. When a leak is detected, the system shuts off the water supply within 10 seconds and alerts a plumber, who arrives with details about the issue. Sensor Networks estimates that 40–50% of intercepted leaks would have escalated into costly claims without this intervention. This figure comes from an analysis of four years of insurance data, though the full study was not shared for review.
Beyond individual homes, Sensor Networks is testing demand management by examining whether groups of connected geysers can reduce peak electricity use. A commercial trial with Ariston involves about 1,000 households, with their heaters collectively rated at 3–4 MW. The goal is to shift demand away from grid strain periods, though no measured reductions have been publicly confirmed. Balancing energy savings with households’ hot-water needs remains a challenge.
Expanding access through training and partnerships
Scaling the technology requires more than hardware. Sensor Networks has trained over 400 plumbers to install and maintain the systems, combining traditional trades with digital troubleshooting. The company is also exploring factory integration with Ariston to simplify deployment, though no timeline for broader adoption has been set.
For insurers, the model raises a key question: Can preventive technology justify its cost by consistently reducing claims? Early data suggests it can, but long-term success depends on whether savings and avoided damage remain reliable as the programme expands. The next phase will determine whether this approach can move beyond pilot projects and reach more African households, where electricity costs, housing conditions, and insurance access vary widely.
The R50 million in estimated energy savings over 18 months comes from a precise calculation. Sensor Networks’ system logs energy use every five minutes and compares it against a baseline: a standard geyser kept at 65°C without scheduling. Using South Africa’s electricity tariff of R3.20 per kilowatt-hour, the company multiplies the average monthly saving of 125.6 kWh by 6,900 active geysers, representing the mid-point of its installed base during the period. This yields R49.93 million, rounded to R50 million. The figure accounts for the expanding fleet but does not reflect verified reductions on individual bills, as household behaviours and tariffs vary.
