How too much solar could ‘collapse the grid’

[Nat Quinn]

How too much solar could ‘collapse the grid’

Electricity minister Kgosientsho Ramokgopa caused a stir of confusion on Sunday (26 June) after warning in a media briefing that adding too much solar in the country could collapse the grid.

Ramokgopa said adding a lot of photovoltaic (PV) generation capacity to the grid at once could cause it to collapse.

“There are pitfalls to the rate at which you add new generation from solar PV. It has the potential to collapse the grid,” Ramokgopa said.

Grid collapse, on a technical basis, occurs when alternating current frequency fluctuates significantly above or below its setpoint. In South Africa, 50Hz is the frequency that keeps the grid alive.

However, the minister did not expand on how adding solar energy to the grid would lead to this eventuality.

Speaking to Newzroom Afrika, Head of Energy Secretariat at the SA National Energy Development Institute, Professor Sampson Mamphweli, attempted to clear up the matter, saying the minister was likely speaking in a broader context of the national grid and its capacity constraints.

“There is context to the statement that the minister made – we’ve been looking at the SA grid for a long time to see if we have enough grid capacity for new generation capacity – not only solar and wind, but all new capacity,” he said.

He said that in areas with the most resources for renewable energy – the Northern Cape, Eastern Cape and Western Cape – capacity is full.

These are the areas where most of the 6,000GW-plus of new projects are taking place.

“Therefore, they have taken over most grid capacity in those areas; we no longer have grid capacity there,” he said.

Mamphweli said that grid capacity is like a water pipeline that can carry a certain amount of water.

“If you try to push more water than it can carry, it essentially bursts,” he said, alluding to Ramokgopa’s comments about collapse.

“So we need to strengthen the grid in those particular areas (the Cape), while we take projects to other provinces where we still have capacity,” he said.

The country still has grid capacity in places like Limpopo, Mpumalanga and Gauteng, he said, which is why Eskom has made land available to independent producers in those areas.

Mamphweli said that grid capacity is very important, and the national grid, as it stands, needs strengthening. He noted that it’s largely on the transmission lines side of things that needs to be strengthened, adding that Eskom likely needs R210 billion to accomplish this.

Eskom has known this for many years, he said, but the main challenge has been funding. Any profits or savings the embattled utility has managed to secure has always gone into servicing debt – so there has been no money for the grid.

He welcomed the talk by the electricity minister that talks were underway with the private sector to partner on solutions to this.

He said a solution would be for the private sector to come in, build the grid, operate it until break-even or they’ve got their money back, then transfer it to the national government.

 

source:How too much solar could ‘collapse the grid’ – BusinessTech

[Author]

Posts