While South Africa grapples with more Nersa tariff hikes for Eskom and the City of Johannesburg is locked in intense negotiations with independent Kelvin power station to ward off load-shedding, the University of the Witwatersrand has quietly joined the renewable energy revolution.
History was made on Wednesday, 15 May when the first sub-Saharan Africa district heating plant was unveiled at Wits University, which is expected to save the higher education institution millions of rand in energy costs over the lifetime of the plant.
The unveiling comes after the National Energy Regulator of South Africa granted Eskom a further 15.63 percent tariff increase, which means municipalities across the country will have to hike what they charge for electricity by a similar percentage.
The Wits Junction district heating project combines solar, co-generation and gas heating technologies, servicing 14 student residence buildings with hot water from one centralised hot water plant room. Installation includes a 600 square-metre solar heating plant with 10 square metre collectors.
There are 1 103 students in the 14 buildings, with an average consumption of 94 000 litres of hot water per day. Peak demand is in the morning, averaging 30 percent of daily consumption, with a maximum demand of 28 200 litres in an hour.
"The system supplies the entire hot water demand, including kitchens, laundry, cleaning and other domestic uses. Each student has his/her own kitchen and there are some centralised service rooms for cleaning staff,” explained Wally Weber of BlackDot Energy, one of the project developers.
Weber said since the system was commissioned, complaints of not having hot water have decreased by 98 percent. "The redundancy design guarantees supply, even during maintenance periods. Estimated cost savings are R40-million rands over the next 20 years and already Wits has seen substantial electricity savings over the trial period of eight months," he said.
There is currently a back-up water system installation in progress, with 300 000 litre tanks, and a more advanced logging and measurement system is planned.
“The system has been a major success in not only meeting financial and energy saving parameters but in vastly improving service delivery levels. The small interruptions are from municipal water or when the main circulation pumps are blocked by debris in the water,” he said.
The heating plant is managed by the Centre for Renewable and Sustainable Energy Studies at Stellenbosch University and the South African National Energy Development Institute, in partnership with AEE-Institute for Sustainable Technologies from Austria. It is funded by the Austrian Development Agency and co-funded by the OPEC Fund for International Development.
