Farmers in the Western and Northern Cape want to accommodate wind turbines on their land to generate electricity in win-win agreements with private business, but there could be limited capacity available on the national grid to accommodate the amount of power this renewable energy can produce.
The department of energy received 364 responses — representing about 20000MW of renewable energy capacity — from private developers in response to a request for information for the initial phase of South Africa’s renewable energy feed-in tariff programme, said Hermann Oelsner, president of the African Wind Energy Association.
But the department’s new independent power producer procurement programme is designed to secure a target of just 3725MW to be generated from renewable energy sources.
Eskom did a study in the two provinces to give wind energy projects — or renewable energy generation developers — a better understanding of the available capacity for connection to the transmission network due to be ready this year.
The study, “Generation Connection Capacity Assessment of the 2012 Transmission Network”, said wind energy would have one of the largest impacts on the transmission network and, to date, the flood of renewable generation applications had been for wind generation.
For Eskom, issues such as how much capacity will be needed at specific connection sites at any one time remain uncertain because of the large number of applications.
Mark van Niekerk, project manager at independent power producer Juwi Renewable Energies in Cape Town, said it would pay farmers an income for as long as 25 years for each wind turbine erected on marginal agricultural land.
“Once areas of adequate wind potential have been identified, we have to determine if there is sufficient available capacity in Eskom’s grid to feed in the electricity to the network,” he said. “We also have to study wind speed for at least a year to ensure a steady supply on behalf of our investors.”
The Denhami wind farm near Struisbaai in the Western Cape is planned for a site that boasts high average wind speeds, suitable proximity in relation to the existing electricity grid, minimum technical constraints from a construction and technical point of view, as well as a perceived low overall impact.
But consultants Savannah Environmental said the operational capacity of the Denhami facility would depend a lot on the capacity of the Eskom transmission grid to transmit the power from where it was generated to where it was consumed.
Eskom has its own flagship wind energy project in Vredendal and has secured funding for its 100MW wind plant in Ceres, both in the Western Cape. It is also working on two new sites in Kleinzee in the Northern Cape and Aberdeen in the Eastern Cape, according to spokesperson Mandli Mbusi.
Eskom hopes that the 100MW Sere wind farm in Vredendal will be a catalyst for the development of renewable energy in South Africa and the rest of Africa. The project is registered with the department of energy as a clean development mechanism project.
According to Eskom, its transmission network is designed for all applications at the various connection points. If only a portion of the capacity is actually installed, it will result in “overdesigned” networks and excessive capital investment and the cost of supply will rise.
The parastatal receives renewable energy applications throughout the year that constantly change the capacity design requirements for the connection points — and therefore the transmission network design requirements as a whole.
All these applications can result in the need for new transmission lines and substations that require environmental authorisation before construction can start.
Independent power producers such as Juwi negotiate an appropriate land lease agreement with the farmer, conduct a full environmental impact assessment and a rezoning process for the placement of wind turbines, once they are confident about wind speeds on a farm.
They then consult all interested and affected parties and submit a bid to the department of energy as part of the request-for-proposals process.
If preferred bidder status is awarded, the independent power producer submits an application to the National Energy Regulator of South Africa (Nersa) for an electricity generation licence within 14 days of receiving notice. The process can take as long as three years and several companies are competing for the possibility of generating electricity.
Nersa played a facilitation role by trying to ensure that third parties were given unbiased access to the existing electricity network, said Nersa spokesperson Charles Hlebela.
He said wind energy projects would definitely help South Africa with additional generation capacity. “One must take into account the fact that wind is an ‘infinite’ natural resource that is renewable. The more we use it, the cleaner our environment in our quest to achieve sustainable development and pursue the objectives of a green economy.”