Robben Island Solar Microgrid

The objective of the National Department of Tourism of South Africa was to reduce Robben Island’s reliance on diesel generators as a power source. 


  • Cape Town, Western Cape, South Africa


  • National Department of Tourism of South Africa (NDT)

Project Status

  • Completed in 2017

The National Department of Tourism (NDT) of South Africa appointed WSP as advisor in the development of renewable energy projects at state-owned tourism attractions. The Robben Island Museum – a UNESCO World Heritage Site and the prison where Nelson Mandela was held captive for 18 years – was identified for the pilot project phase. 

WSP first assessed various renewable technologies for this sensitive UNESCO World Heritage Site and then proposed a solution that took available wind and solar resources into account, along with marine conditions and the rich local wildlife.

A Brief History of Power Supply

The power supply on Robben Island initially consisted of a small, diesel-fuelled MV reticulation system that supplied 90 houses, administrative buildings, a small harbour and the island’s desalination plant. The WSP team assessed the existing infrastructure, conducted a baseline load study and evaluated various renewable technologies for use on the island.

Our environmental team conducted an availability analysis for wind and solar resources to determine the best fit for the island’s energy needs. WSP was also involved in assessing marine conditions, environmental challenges (particularly breeding colonies of very rare birds and penguins on the island) and heritage issues associated with this historic site. 

Thanks to our experience and good relationship with various stakeholders, we were able to quickly perform the environmental assessment for a location where it was challenging to obtain a permit. 

WSP ultimately suggested a solar PV in combination with a battery system as the best solution for Robben Island, transforming the project from a basic solar installation to a ground-breaking microgrid system. 


Robben Island prison gate

Total size
666.4 kWp 666.4 kWp
Battery size
837 kWh 837 kWh
Diesel saved
280,000lt pa 280,000lt pa

Engineering Real Energy Savings

Our renewable energy experts engineered preliminary layouts and orientations for the solar installation, conducted energy yield assessments to maximize the use of the available space and designed a battery system to cover night loads. 

The microgrid controller assesses the options available at all times (diesel vs solar vs battery) and selects the lowest cost generating option using a polling system, with solar, battery and diesel generation in order of preference. The installed system is a 666.4 kWp DC Solar Array with an 837 kWh battery system.  

The microgrid system will save Robben Island approximately 280,000 litres of diesel per year, which adds up to savings of approximately R5,000,000 per year. The payback period is in the order of five years.

Because the project is built on a UNESCO World Heritage Site, we considered not only the safety of the tourists and inhabitants of the island, but also the safety of resident creatures such as the Black Oyster Catcher and the Cape Penguins that nest and breed on the island. To ensure the safety of these rare birds, WSP asked the EPC to undertake penguin handling training and had the site penguin-proofed during construction. No incidents occurred, even with the penguins. 

The client has stated that they intend to use the project as an example of how private and public sectors can successfully collaborate to provide a leading-edge solution, on time and budget.  


Robben Island solar array

World-Class Energy Solutions

The design itself incorporates the best technology, including the ABB powerstore and controller, Samsung lithium ion batteries and Canadian solar panels. Due to the harsh environment of the site and the iconic status of the Robben Island, every effort was made to ensure the design was world class. 

For decades, Robben Island relied solely on the use of diesel generators as a power source. This project was the NDT’s first step in a phased approach to reduce the island’s reliance on fossil fuel sources and its environmental impacts.

WSP’s Power team provided an energy vision for the Robben Island Museum to include in their Integrated Resource Plan for the island. This plan aims to remove diesel from the island’s energy mix in the coming years, tackling both the demand side, by reducing the load, and the supply side by increasing the battery storage. At this point, diesel generators will remain purely as back up.

Our team conducted a baseline energy efficiency audit, which led to a program to replace inefficient light bulbs on the island and thereby reduce demand side load. 

In addition, we partnered with the University of Stellenbosch on a heat pump initiative, allowing one of the university’s graduate students to complete his thesis on a revolutionary metering device that is installed in a home’s distribution board.  

The device logs and measures geyser utilization over up to a year. There are approximately 60 element geysers installed on the island, and the student produced a feasibility study on replacing the geysers with efficient heat pumps. The cost of wholesale replacement should amount to approximately R1.2 million, with a projected payback period of 1.5 years.