South Africa is overlooking solar technology that can keep generating electricity after sunset

South Africa’s coal-fired power stations are retiring.

The country must replace a huge amount of electricity over the next two decades.

Currently, coal still supplies 74% of the country’s power.

But the government’s national energy plan has largely overlooked one technology South Africa is particularly suited to build: concentrating solar power.

There are two main ways of generating electricity from the sun.

Photovoltaic (rooftop) solar panels convert sunlight directly into electricity.

Big concentrating solar power farms use mirrors to concentrate sunlight into heat.

This heat is then used to produce steam that drives a turbine to generate electricity.

Concentrating solar power works only with direct normal irradiance.

This is sunlight that travels straight from the sun, rather than light scattered by clouds, dust or moisture.

This direct sunlight can be concentrated to produce extremely high temperatures.

Read more: Why southern Africa’s interior is an ideal place to generate solar energy Because of its dry climate, clear skies and low cloud cover, South Africa has some of the best direct normal irradiance in the world, second only to Chile’s Atacama Desert .

South Africa once planned to build more concentrating solar power plants, but those plans were gradually scaled back.

No new projects have been approved since 2014.