Renewable energy is a disaster and will collapse SA’s electricity supply system - Andrew Kenny

South Africa is lurching towards another electricity disaster to make the Eskom disaster even worse.

It comes from “renewable energy”, which here usually means solar and wind.

These are excellent for off-grid uses, such as solar water heating, wind pumps on farms, and small electricity supply for households.

But they are useless for grid electricity (electricity on national electricity networks, such as Eskom’s).

The sun never makes electricity when it is most needed – on winter evenings just after sunset.

With wind you never know when it will make electricity.

Both are staggeringly expensive and hopelessly unreliable.

South Africa has more than three years of data showing how bad solar and wind electricity is here.

This comes from REIPPPP – the Renewable Energy Independent Power Producers Procurement Program.

Under it Eskom is forced to buy extremely costly solar and wind power from independent power producers.

I have the production figures for REIPPPP. They are terrible, showing wild, unpredictable ups and downs in power production.

According to Eskom’s latest annual report for the year ending 31 March 2018, Eskom’s average selling price is about 89 cents/kWh (kilowatt-hour).

The average price it is forced to pay for renewable electricity is 222 cents/kWh – over double its selling price.

But this is the price Eskom pays for REIPPPP electricity; it is not the cost to Eskom, which is much more. This is because of the system costs.

The most important equation in costing renewable electricity: cost of renewable electricity = price of renewable electricity to the grid + system costs.

The system costs are the huge costs of incorporating the fluctuating, unreliable solar and wind power into the grid so that it can provide reliable electricity at the right frequency and voltage.

They include the back-up generators; the extra costs incurred by these generators ramping up and down to match the renewables and so using more fuel and incurring more stresses; spinning reserve (generators running at below optimum power); storage; extra transmission lines; and increased shut-downs caused by the renewables.

If the price of renewables to Eskom was 20 cents/kWh, the system costs would still make it prohibitively expensive.

We perhaps can get some idea of them by looking at the one honest renewable technology that covers its own system costs.

This is Concentrated Solar Power (CSP) with storage. The latest CSP plants charge Eskom about 500 cents/kWh at peak times.

This is probably something like the true costs to Eskom of wind power and solar PV (photovoltaic panels, making electricity directly from sunlight).

Our electricity supply system is heading for collapse. Forcing South Africa to abandon coal and nuclear for wind and solar will make it collapse altogether.

- Andrew Kenny is a professional engineer and a freelance journalist.