Oct 11, 2023

Harnessing Innovation: The Project Smart Geyser Transforms Energy Efficiency

Imagine a world where your morning shower not only invigorates you but also contributes to a greener, more efficient energy landscape. That vision is becoming a reality in Cape Town and the Hessequa Municipality, thanks to the groundbreaking Project Smart Geyser. 

This innovative initiative features the deployment and operation of HotBot, a retrofittable intelligent geyser controller from Plentify. 500 HotBots were strategically placed across Cape Town and surrounding areas (418) and Hessequa Municipality (82), divided into five distinct fleets representing various market segments, including general metro households, high-end estates, retirement villages, heavy consumers, and general local municipality households. 

The overarching goal of this collaborative project was to explore the potential of HotBot in reducing bulk electricity costs for municipalities, cutting down electricity expenses for households, mitigating load shedding, and enhancing the business case for solar energy. The project evaluated three key services: 

  • Load Reduction: This involves minimizing power consumption by coordinating a fleet of geysers during specified periods, contributing to significant energy savings.
  • Maximum Demand Management: By staggering power usage within a fleet of geysers, this service reduces aggregate maximum demand. This can alleviate demand charges, prevent infrastructure damage from load spikes, and enable a smoother energy grid.
  • Distributed Solar Load Building: Coordinating geyser energy use to align with solar generation profiles creates more demand during sunny periods, allowing for larger and more cost-effective solar systems.

The results of this pioneering project have been nothing short of remarkable. From August 29, 2022, to August 3, 2023, the experiments showed that geysers have the potential to reduce energy and load at targeted times, manage maximum demand effectively, and align energy use with solar generation.

The accomplishments of this fleet of Hotbot controlled geysers are noteworthy:

  • Improved energy efficiency by up to 30%
  • Reduced peak load by more than 80%
  • Lowered maximum demand by over 50%
  • Enabled solar PV systems with more than twice the capacity at the same utilization rate

All these achievements have been realized while ensuring users have hot wa  ter when they need it. The Project Smart Geyser is a testament to how innovation can drive energy efficiency and sustainability, promising a brighter, greener future for South Africa and beyond.

Contact Person:
Zanele Hakamela – 
Advisor for Technology Innovation and Gender Mainstreaming | zanele.hakamela[at]giz.de


The Project Smart Geyser was implemented across municipalities in the Western Cape by the South African-German Energy Programme (SAGEN) in collaboration with EEP Africa. SAGEN collaborates with South African partners to support the country’s transition to a reliable, affordable and clean energy future. SAGEN is funded by the German Federal Ministry for Economic Cooperation and Development (BMZ), co-funded by the Swiss State Secretariat for Economic Affairs (SECO) and implemented by the Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH in cooperation with the Department of Mineral Resources and Energy (DMRE), the National Treasury (NT), Eskom, the South African Local Government Association (SALGA) and the South African National Energy Development Institute (SANEDI).

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