Virtual Power Plants can fight SA’s energy crisis while building for the future

We conducted a multi-year project that demonstrates how smart water heaters can fight blackouts and enable solar.

Our 30-month study in South Africa’s Western Cape province has found that a smart water heater management system could reduce morning and evening blackouts in major cities by 20 hours per household per month if installed in 25% of households.

Under the project, 500 electric water heaters in Cape Town and the Hessequa Local Municipality were equipped with management devices. The study compared 19 months of baseline measurements against nearly 12 months worth of data following the installation of the devices, called HotBots. 

We found that the devices reduced each water heater’s electricity use during peak periods by up to 80%, without affecting the supply of hot water to the participating households.

It also improved each water heater’s overall energy efficiency by up to 24%, and cut maximum demand at any point in time across the fleet of water heaters by up to 60%. Since this shifted energy needed to go somewhere, the HotBots coordinated much of it to match solar generation, which demonstrated that the technology can double the feasible size of solar plants.

How does it work?

The devices use artificial intelligence to automatically turn water heaters on and off at the most optimal times, with the aim of shifting electricity demand away from morning and evening peaks, taking advantage of periods of strong solar output, taming the spike in demand that follows rotational rolling blackout periods, and reducing overall power demand.

Backed by climate tech investor Third Sphere, Plentify was founded by Jon Kornik and Kailas Nair, the former leads of Google’s energy business in Africa and Discovery’s insurtech business, Vitality, in  North America, respectively. Its advisors include Evan Rice, former head of Tesla Energy’s Europe, Middle East and Africa unit.

Plentify CEO Jon Kornik says:

“This pilot project demonstrated that water heater management systems can be a powerful tool for cities looking to fight blackouts and adapt to an energy system transitioning to renewables, while also ensuring that households have hot water when they need it and can benefit from lower energy bills,”

Richard Larmour, Researcher and Measurement and Verification specialist at the University of Cape Town says:

“This piece of work undertaken by Plentify represents the cutting edge of residential hot water management in South Africa. It is a welcome addition to an area which is grossly understudied.”

The project was a partnership between the two participating municipalities, German development agency GIZ, clean energy financing facility EEP Africa, Plentify, and others. The project was overseen and advised by the University of Cape Town’s M&V Inspection Body.

Ready to experience the benefits of HotBot for yourself?

Enjoy reduced electricity bills while HotBot gets your geyser to work smarter not harder.