A new sun-tracking system, which could uplift the performance of South Africa’s concentrated solar power (CSP) plants, is attracting attention.

CSP plants, which use mirrors to convert sunlight into steam that drives green electricity- generating turbines, are able to supply electricity on demand, during day or night.

Interestingly, CSP plants are now facing the good fortune of being rendered more competitive by the new sun tracker, which has been brought to market by German technology company Cambras, whose founders, Alexander von Sperber and Lukas Kirscht, along with the company’s South African partner, Guenter Schmitz, spoke to Engineering News & Mining Weekly in a Zoom interview, following their return to Germany from a fruitful visit to South Africa’s Bokpoort and Kathu CSP plants.

“We increase the yield of CSP solar power plants, and, in parallel, are responsible for a stable operation, as well as longer duration, which is very decisive for return on investment,” said Von Sperber, who set up a demonstration installation at the ACWA Power Bokpoort CSP plant, which is part of South Africa’s Renewable Energy Independent Power Producer Procurement Programme in the Northern Cape.

At the heart of Cambras’ tracking system is optical sensoring and software that controls temperature fluctuation.

“It’s now proven by official records that we increase the thermal output of the solar field by a minimum of 10%, and overall electrical output by more than 3%,” Kirscht pointed out.

While, for better or for worse, passive tracking follows calculated sun positions, the active tracking provided by the new system reacts immediately to new situations and keeps temperature in check, Cambras states on its website.

“We’re a very small tech company in Germany, and our business is very international, because all the CSP power plants are abroad, where the sun is shining,” said Von Sperber.

Engineering News & Mining Weekly: What will be the likely cost of CSP upliftment you envisage?

Von Sperber: The costs are very specific to the challenges of each power plant, because the main challenge is also to integrate the system in an operating power plant in order not to generate any downtimes during installation, and this is related very much to the cost of the system, because we offer the customer a modular system. Basically, you can roughly estimate that the return on investment for each customer will be around one to two years, at most.

Solar-Thermal Power

Solarpaces reports that all CSP technologies use a mirror configuration to concentrate sunlight energy onto a receiver and convert it into heat that can be used to create steam to drive a turbine to produce electrical power or used as industrial process heat.

Solarpaces adds that CSP plants built since 2018 integrate thermal energy storage systems to generate electricity during cloudy periods or hours after sunset or before sunrise.

This ability to store solar energy makes concentrating solar power a flexible and dispatchable source of renewable electricity, such as other thermal power plants, but without fossil fuel, as CSP uses the heat of highly concentrated sunlight.