For the first time, a full-scale solar power tower is under construction on the continent of Africa, with Abengoa announcing this week that work has begun on the 50-megawatt Khi Solar One project in a remote area of the Northern Cape province, near Upington, in South Africa.
Power towers use heliostats – essentially large mirrors – to direct light onto a receiving tower, where water or other fluids can be heated and then used to produce energy.
Spain has a trio of such plants, including what is the largest one operating in the world, the Abengoa-built PS20, which has a 20 MW capacity.
Other power tower plants are under construction in the United States that will take the size to a completely new dimension: Crescent Dunes in Nevada, expected to be operating before the end of next year, will have a capacity of 110 MW, and the three-tower Ivanpah project in California, more than halfway done, will deliver up to a whopping 392 MW.
There’s also a project unfolding in China, a 10-tower, 50-MW configuration, but it was begun nearly two years ago and apparently the first tower is just now nearing completion.
In South Africa, Khi Solar One will offer two hours of thermal storage, Abengoa said – not quite the extraordinary total of up to 15 hours that the company’s Gemasolar plant in Spain, which uses molten-salt technology, offers, but enough to smooth power flows and extend production into the evening hours.
When it won the Khi Solar One contract late last year Abengoa also nabbed a second concentrating solar power contract as part of a total 1,416 MW in renewable energy projects South Africa handed out then (by 2030, South Africa hopes to have 17,800 MW of renewable energy online). That second Abengoa project in South Africa also got under way officially this week – it’s a 100 MW parabolic trough plant, also in Northern Cape, about 150 miles west of Uppington near Pofadder. KaXu Solar One will offer storage of up to three hours.
“CSP’s ability to be dispatchable will be a great advantage for South Africa as it will permit the country to bring more intermittent technologies, such as photovoltaics and wind into their renewable energy mix,” Abengoa said.