Years ago, there was not much interest in solar technology in South Africa. Solar panels were a rare sight in South Africa, largely limited to the roofs of a few affluent households. This is changing rapidly, driven by three factors: the worldwide drive towards renewable energy, a highly strained local electricity supply, and a steady drop in solar panel prices.
South Africa’s climate is ideal for solar. Most areas in the country average more than 2500 hours of sunshine per year, among the highest in the world, thanks to its Equatorial position. The more light the panels receive, the more electricity they generate and they work on cloudy days too.
As electricity costs keep rising, solar is becoming an even more viable and cost-effective option for businesses in South Africa. While there is an initial outlay cost, it can be recouped after five to eight years on average. That’s an attractive internal rate of return (IRR) especially considering solar electricity is then free after the initial payback period. So solar PV actually offers businesses an attractive savings model.
Taking the lead from other countries, South Africa committed to an energy generation infrastructure development plan for 2010 to 2030, known as the Integrated Resource Plan.
Under the plan the country aims to achieve 9600 MW of solar power capacity by 2030. When the plan was drawn up in 2010, solar was limited to a few isolated panels on domestic rooftops, and until recently contributed nothing to the national power grid operated by the state-owned utility Eskom.
But that is changing. Solar plants are being developed, most by the private sector under a specially designed procurement program. Eskom is also constructing some facilities.
In the last ten years the defining development in solar energy has been the sharp drop in the prices of photovoltaic panels. There has also been modest technological advances in other solar technologies and in power storage.
Research advances over the years, especially those involving easily available silicon-based materials, have made this an increasingly cheap solar technology. It is also now the most popular.
The simplest PV configuration has immobile solar panels, slightly tilted relative to the ground and facing northwards towards the midday sun. An example is the Droogfontein Plant near Kimberley in South Africa’s Northern Cape province. Panel rows are placed in a way to ensure that each panel does not shade the one behind it.
A more sophisticated design, found at the Sishen Plant near Kathu, also in the Northern Cape, uses a single axis-tracking technology to counteract efficiency losses. Each row of panels steadily rotates along a north-south axis with the sun until it reaches a point where it starts to shade the row behind it.
In two-axis tracking systems, panels constantly face the sun squarely. The Herbert and Greefspan plants near Douglas in the Northern Cape use this technology. The cost of the additional tracking motors is compensated for by the capture of more sunlight.