Sunny SA's rooftops have plenty of space to power up the grid

Solar panels on existing public and commercial buildings could pump 12GW back into our electricity system, enough to power six million homes a year. But first we need solid regulations.

- By Mamahloko Senatla Jaane

South Africa has many factories, warehouses, schools and hospitals — big buildings with large rooftop spaces.

In such a sunny country, these flat surfaces would be perfect for large photovoltaic solar systems that could generate enough renewable energy to supply the buildings they're on and feed into the national grid. This would reduce the amount of coal that South Africa's national electricity provider would need to burn.

Renewable energy engineer and PhD candidate Mamahloko Senatla-Jaane was part of a team who researched how commercial buildings could be set up to serve as strategic assets for decarbonisation and increase the security of South Africa’s power supply.

How much space is available and how suitable is it?

We calculated that 111 million square metres of rooftop space is available on the roofs of universities, schools, hospitals and commercial buildings like shops, warehouses, office blocks and factories.

Our research also found that 80% of these roofs were highly suitable for solar panels. The amount of electricity that commercial building rooftops could hold is 12GW, or roughly enough to power about six million homes of six people each per year.

There is no public record of the number of commercial buildings and individual size of their roofs. So, we used publicly available statistics about floor space to calculate the roof space using a floor-space to roof-space conversion factor.