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- Cool-surface paint is being rolled out at the military bases in Limpopo, one of South Africa's hottest provinces.
- The paint cools down buildings and helps cut down the use of air-conditioning, says the South African National Energy Development Institute.
- It is the largest project of its kind for sub-Saharan Africa and will cover an area of more than 130 rugby fields.
- For climate change news and analysis, go to News24 Climate Future.
Paint that has the ability to cool down buildings is being applied to military bases in Limpopo, one of South Africa's hottest provinces.
The five-year project, which started in 2021, is the largest of its kind in sub-Saharan Africa, according to the South African National Energy Development Institute (SANEDI).
By the end of 2025, when the project is complete, an area of 1.37 million square metres will be covered – or more than 130 rugby fields.
Already, by the end of 2023, 366 000 square metres or an area roughly the size of 36 rugby fields had been covered. This included housing for staff, schools, creches, clinics and mega military structures – making these spaces more comfortable and helping to cut down air-conditioning use, according to SANEDI.
Some residents have shared that the paint has made their offices "a bit chilly" in winter, according to Dr Karen Surridge, who is leading the project on behalf of SANEDI.
"The paint was developed internationally by the American and European markets and has been in use for well over two decades at a global scale," said Surridge.
The paint is manufactured locally – and contains a specific titanium compound – similar to that found in sunblock to allow for cooling:
According to Surridge, the paint manufactured in South Africa is environmentally friendly and can be applied to any surface. "It does not require any special disposal or treatment in waste management," Surridge added.
Before applying the cool-surface paint, old paint has to be stripped off completely, and surfaces must be primed for a new coat.
"… much like sunscreen that also protects, the cool-surface paint has to be applied to a certain thickness," SANEDI said.
Given the specifics of how paint should be applied, the project has involved training and upskilling of artisans in the military. So far over 50 new jobs have been created through the project.
Among the skills and jobs required include roof inspections, site preparation, minor repairs to roofs, as well as the use of scaffolding, and health and safety procedures and quality checks. The project is expected to create more jobs.
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Surridge will also be using the data from the project for her research into the "cool-bubble" effect in South Africa. International research has found that in high-density built-up areas, a bubble of cooler temperature forms over and between buildings – this as the paint pushes away heat, according to SANEDI.
"The large bases we are painting are like towns themselves, making them ideal to measure the cool-bubble effect under local conditions," said Surridge.
The research would provide information on the impacts and benefits of cool-surface paint in South African cities – which could also advise government policy. The hope is that at least government buildings would be coated in cool-surface paint.
"The project with our military partners is not even halfway yet and already we are seeing great results," said Surridge. "The data shows a marked difference between coated and uncoated buildings, and the energy savings are considerable," Surridge added.
In cooler buildings, air-conditioning units don't have to work as hard, which saves electricity and maintenance costs over the lifespan of a unit, according to Surridge. The paint is 30% more expensive than ordinary paint but has a minimum lifespan of 10 years – which will also limit maintenance expenses.
The paint is also useful in slowing the advancement of fires, allowing people two extra hours to vacate a burning building, according to SANEDI.
SANEDI initially tested the use of cool-surface paint in the early 2010s in the Northern Cape.
The current project forms part of the global Million Cool Roofs Challenge, aimed at scaling up solar-reflective roofs in developing countries that suffer heat stress. The Department of Mineral Resources and Energy mandated the project.
