Robben Island, off the coast of Cape Town, South Africa, is steeped in history and is a popular tourist attraction, attracting thousands of tourists a day. In the past it was used as a prison, with its most notable prisoner the former President, Nelson Mandela. Today tourists can see another attraction: A solar+storage microgrid that has one of the southern hemisphere’s largest battery banks.
Meeting the energy needs
The energy requirements of the island include providing power to the 100 staff that live on the island, a lighthouse and a desalination plant—as well as powering the many tourist attractions on the island.
The island uses about 2 million kWh of electricity a year, and in the past it has depended on diesel generators for its electricity. The Tourism Department in South Africa decided to install a solar park on the island, as part of its retrofitting program aimed at developing tourism attractions.
Tourism Minister Derek Hanekom said in a Budge Vote speech, “The exciting part of the retrofitting program is that it contributes towards our countrywide effort to reduce the electricity demand and to start shifting towards efficient energy use and renewable energy use.”
Designing and constructing the microgrid
The Department of Tourism’s EPC partner, SOLA Future Energy, which designed and constructed the solar and lithium ion storage microgrid using 1960 Canadian Solar (CS6U-340M) high-efficiency PV modules mounted on fixed-tilt racking, providing a total of 666.4 kW power.
The battery bank is made up of 2420 battery cells, capable of storing 837 kWh worth of electricity and supplying 500 kW worth of peak power. The microgrid has ABB Ability remote monitoring capability that enables the system to be monitored and operated from Cape Town, 9 kilometers away.
The microgrid runs solely on the sun during the day, and with battery backup, can operate for up to 7 hours after the sun goes down. The system will produce about 1 million kWh of electricity annually, cutting the cost and use of diesel fuel in half, saving an estimated 4 million rand (about $3 million US) annually.
A win for the island's inhabitants
In addition to the historic sites on Robben Island, it is also home to a variety of species of birds, including the African jackass penguin. By using the sun as a resource, the island’s microgrid is reducing the need for noisy, polluting diesel generators—and cutting boat traffic to and from the island, which was needed for fuel deliveries. During its first two months of operation, the microgrid produced 187,000 kWh of clean electricity, saving 53,685 liters of diesel or the equivalent of 495 tons of Co2 emissions. That’s a win for all of the island’s inhabitants and a shining example of efficient and clean energy for the thousands of tourists.
Written by Anne Fischer, Managing Editor, Solar Novus Today