Integrating wind into South Africa’s grid
South Africa’s power grid has gotten a fair amount of bad press in the past. Adding wind into the equation shouldn’t hurt, though… provided Eskom is on side.
By Jason Deign
Go back just over half a decade and South Africa was putting the ‘grrr’ into ‘grid’.
“By early 2008, South Africa’s strong economic growth, rapid industrialisation and a mass electrification programme led to demand for power outstripping supply,” recalls MetroWind, the special purpose vehicle backing the Van Stadens Wind Farm project, on its web site.
“The government’s plan to bring South Africa’s electricity supply and distribution system back into balance included a massive Eskom programme to upgrade and expand the country’s infrastructure, introducing ‘load shedding’ or planned rolling blackouts.”
Such power cuts are now thankfully a thing of the past, although South Africa is still recognised as treading a thin line between power supply and demand.
Hence the country’s push for alternative generation sources through the Renewable Energy Independent Power Producer Programme, within which wind plays a prominent role.
But could large amounts of wind power have an adverse effect on South Africa’s already stressed grid infrastructure? Right now, the main concern for the industry is whether projects will be able to connect to the grid in the first place.
All about size
Johan van den Berg, chief executive of the South African Wind Energy Association, says: “South Africa is a very large country, the size of Italy and France, more or less, so while we have a well-established grid there are a lot of places that the grid does not go to.
“What happened in the early days, when people started developing renewable energy, is that the sophisticated developers looked for places where the power could be evacuated quite easily,” says Van den Berg.
He believes there is plenty of scope for further additions without needing massive grid additions. “Everything we are building now and that we will build for the next while is in places where grid integration is reasonably painless,” he says.
Nevertheless, Eskom is planning ahead when it comes to projects further afield, according to Steve Ross, managing director for Europe, Middle East and Africa at the renewable energy risk analysis company 3TIER.
“South Africans have a 10-year plan of powering the country through wind,” he says. “They are looking for a 20% position, which is in the region of 4 to 6GW of wind power coming onto the South African grid. It is aggressive.”
Ross says South Africa envisages adding wind capacity in three separate contexts: off grid, to power isolated communities; close to major conurbations, where grid connections are already sufficient; and in remote locations where the grid may need to be strengthened.
Infrastructure upgrades
In the latter, Ross comments that the country is being careful to match wind project build-outs with infrastructure upgrades. “Whether that is going to be a perfect mix, there’s a debate,” he cautions. “If I was a developer I’d be very concerned about that.”
Van den Berg adds that “some projects will fall out because their grid integration is less easy than some others,” but overall the feeling is that Eskom is doing its homework in terms of grid connectivity.
“I think we can probably reach several thousand megawatts without really concerning ourselves too much about the availability of grid per se,” Van den Berg says.
The other issue is how the grid will be able to cope with large amounts of variable wind power. Here again, though, things look promising, at least based on a 2010 impact study by the Energy Department plus Windlab and GIZ.
In a fact sheet titled ‘Grid integration of wind turbines,’ the Energy Department concludes: “It is very likely that it will be possible to operate the system safely without increased dynamic performance requirements for the conventional power plants of South Africa.”
Dr Pascal Storck, 3TIER’s chief operating officer, confirms that grid integration need not be any more of a challenge in South Africa than it is turning out to be elsewhere.
Changes required
“Is it possible to integrate large amounts of wind?” he asks. “The answer to that, as you go around the world, country to country, is always ‘yes’, with the caveat that some changes are required.
“The lessons learned are always the same: you need to have a large footprint and you need to have fast and flexible markets.”
Regarding the footprint, South Africa is probably big enough on its own to be able to offset wind variability in one area with wind variability in another, in theory at least.
True, the grid might not reach everywhere yet, but with improved forecasting data and technology Eskom could pinpoint regions where grid extensions might deliver the greatest benefit. The second point, about flexible markets, is potentially more of a challenge.
“The biggest problem you have is that the grid would be the off-taker as much as it is the transmitter of the energy. There’s not a lot of competition running across the market. A monopoly will dictate the pace of growth of wind,” says Ross.