28 August 2013
Spanish renewable energy group Abengoa has completed construction of the tower section of South Africa’s first concentrating solar power (CSP) plant, one of three such plants under development in the semi-desert Northern Cape province that will together add 200 megawatts (MW) of renewable energy to the country’s national grid.
Abengoa is one of 28 independent power producers that signed contracts with the South African government late last year, in the first round of a programme that will see an initial 1 400 MW of renewable energy being added to SA’s energy mix, while bringing an estimated R47-billion in new investment into the country.
The Department of Energy aims to bring 17 800 MW from renewable sources online by 2030.
Abengoa, in partnership with the state-owned Industrial Development Corporation (IDC) and community trusts in Upington and Pofadder, is building Khi Solar One, a 50 MW solar tower plant near Upington, and KaXu Solar One, a 100 MW parabolic trough solar plant near Pofadder.
Investment of over R10-billion
According to the Southern Africa Solar Thermal and Electricity Association (Sastela), the two power stations will leverage investment of over R10-billion, and together will generate almost 500 GWh per year of clean solar electricity.
On Monday, representatives of the government, the IDC and the Khi Community Trust attended a flag-raising event to mark the completion of the 205-metre tall tower of Khi Solar One.
Abengoa, who will build, operate and maintain the two solar plants, owns a controlling 51% of the projects, with the IDC owning 29% and community trusts owning the remaining 20%.
According to Abengoa, the two plants will reduce South Africa’s carbon dioxide emissions by about 498 000 tons a year, while creating between 1 400 and 2 000 construction jobs and about 70 permanent operation jobs, as well as numerous indirect jobs to fulfill the needs required by the plant and its construction.
“South Africa has one of the best solar resources in the world, with great potential to be a leader in concentrating solar power generation,” the company said when construction on the plants commenced in November.
Abengoa said on Monday that Khi Solar One represented an important technological advance in CSP tower efficiency “by using higher temperatures and an innovative dry cooling system”, meaning it will use a fraction of the water consumed by wet-cooled power stations.
Both Khi Solar One and KaXu Solar One will have facilities for storing steam, enabling them to provide electricity for up to three hours when the sun is not shining – including during peak demand periods.
Bokpoort CSP power station
The third CSP plant under construction in the Northern Cape, the 50 MW Bokpoort CSP power station near the town of Groblershoop, about 100 kilometres south-east of Upington, is still more ambitious in its storage plans.
The Bokpoort plant is being developed by a consortium led by Saudi Arabian company Acwa Power International, and was the only CSP project of the 19 projects selected by the Department of Energy for the second window of the country’s renewable energy programme for independent power producers.
Annoucing the start of construction on the R4.5-billion project earlier this month, Acwa Power said Bokpoort would be equipped with the largest thermal storage adopted to date for a solar power plant of this class and capacity.
“The plant thermal storage capacity will be 9.3 hours, enabling it to yield a record-high generation in excess of 200 GWh/year well into the night every day throughout the year,” Acwa Power said in a statement.
‘CSP is a base load technology’
“This makes CSP the only renewable technology at commercial scale to cover the country’s daily peak demand from 5 to 9pm, thereby helping to prevent power blackouts.”
Of the 18 900 MW of renewable energy made allowance for in the government’s Integrated Resource Plan, a 20-year projection on electricity supply and demand, only 1 200 MW is allocated to concentrating solar power. Wind energy has been allocated 9 200 MW and solar photovoltaic (PV) 8 400 MW.
The Southern Africa Solar Thermal Energy and Electricity Association (Sastela), which represents the CSP industry, argues that CSP’s ability to provide peak demand electricity gives it the edge over wind and PV, which are restricted by natural and weather conditions.
Michael Goldblatt, a director of Solafrica, which is part of the consortium developing the Bokpoort plant, told Satela recently: “We see development of the Bokpoort plant as an opportunity to prove that CSP is a base load technology … We have designed Bokpoort to be as close as you can get to a base load power station, with the ability to generate electricity virtually 24 hours a day.”
According to Acwa Power, the Bokpoort plant will reduce South Africa’s carbon dioxide emissions by about 230 000 tons a year, while creating 900 jobs during peak construction and 60 permanent jobs once the plant comes on line, and involving South African companies with previously disadvantaged community participation in plant construction, operation and maintenance.
Other members of the consortium developing Bokpoort are the Public Investment Corporation of SA (representing the Government Employees Pension Fund), Lereko Solafrica Investment, Lereko Metier Solafrica Fund 1, Lereko Metier Sustainable Capital Fund, Kurisani Solafrica Investments (representing NGO Lovelife) and Solafrica Community Investment Company.