CSP In Action
Construction of South Africa’s first two Concentrated Solar Power (CSP) power stations will start soon, with development of a third well underway.
The first two CSP power stations will be established by Spanish developer Abengoa in partnership with the Industrial Development Corporation (IDC) and community trusts in Upington and Pofadder, Northern Cape.
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Upington on the banks of the Orange River in Northern Cape is becoming the hub of South Africa's emerging solar energy industry. One of South Africa's first three privately-owned Concentrated Solar Power (CSP) plants is being built on the outskirts of the town where the national electricity utility, Eskom, is also developing a CSP plant. The Department of Energy is also planning development of solar parks in the town and within its vicinity.
Khi Solar One and KaXu Solar One
With their ability to store heat energy and steam, South Africa’s first two Concentrated Solar Power (CSP) plants will be able to supply electricity to the national grid at critical times when the sun is not shining and particularly during peak demand periods.
Situated in the arid Northern Cape, the power stations will also be dry-cooled. They will use about a third of the water consumed by wet-cooled power stations and a fraction compared with irrigated farms, which draw water from the Orange River that runs through the province.
Dry cooling costs more to install, but “it’s the right thing to do”, says Dr Louis van Heerden, general manager of Abengoa Solar South Africa which is leading development of the power stations in partnership with the state-owned Industrial Development Corporation (IDC) and two community trusts.
“We are very aware that we are building power stations in a water-scare country and in a very dry area,” he explains. “There are ambitious plans to build a solar power industry in the Northern Cape, and saving water is a critical part of this. CSP will give new dimensions to the local industry and provide dispatchable renewable power to the national grid.” The costs of dry cooling, he says, are offset to an extent by the two plants’ savings in electricity costs for water pumping from the Orange River and in their water consumption.
The two power stations -- one near the regional centre of Upington, the other near the town of Pofadder – will leverage investment of over R10 billion and will have combined installed capacity of 150 megawatts (MW). Together they will generate almost 500GWh per year of clean solar electricity, sufficient to cover the annual electricity consumption of over 110,000 homes.
Based in Spain, Abengoa is a pioneer in the commercialisation of CSP and brings to the country some 30 years of experience in developing solar technologies. Abengoa operates 543MW of CSP and solar photovoltaic technologies in Spain, and a 150MW integrated solar combined- cycle plant in Algeria where CSP is used in conjunction with a gas turbine plant.
Abengoa is also developing the world’s largest single solar power plant, the 280MW Solana CSP power station in the US state of Arizona. Other developments include the Extremadura Solar Complex consisting of four 50MW CSP power plants in Spain, and the 100MW Shams-1 CSP plant near Abu Dhabi in the United Arab Emirates that is in an advanced stage of construction.
The two power stations, being developed under the South African government’s Renewable Energy Independent Power Producer Programme (REIPPPP), are:
· Khi Solar One, a 50MW power tower plant on the outskirts of Upington and which takes its name from the San word for the protected shepherd’s tree in the Northern Cape. This will be Abengoa´s third commercial solar tower and its first outside of Spain.
The power tower system uses large, sun-tracking mirrors (heliostats) to focus sunlight on a receiver at the top of a tower. Water is pumped up to the tower mounted receiver and is converted to steam, which, in turn, is used in a conventional turbine generator to produce electricity. Of the 36 operational CSP power stations worldwide, five are power towers.
The power station will include a facility to store steam, enabling it to generate electricity for three hours when the sun is not shining.
Abengoa estimates the plant will prevent approximately 183,000 tons of CO2 emissions a year.
An average of 600 jobs will be created during construction, and about 35 people will be employed full-time once the plant is up and running.
· KaXu Solar One, a 100MW parabolic trough plant near Pofadder in Northern Cape and which derives its name from the San expression for a wide expanse of sky. The power station will have a storage capacity of three hours and use molten salt to store heat energy.
In the parabolic trough system, the sun's energy is concentrated by parabolically curved, trough-shaped reflectors onto a receiver pipe running along the focal line of the curved surface. This energy heats oil flowing through the pipe, and the heat energy is then used to convert water to steam and generate electricity in a conventional steam generator. Of the 36 operational CSP power stations worldwide, 23 are parabolic troughs.
Some 800 jobs on average will be created during construction, and about 35 permanent jobs during operation. Abengoa estimates the power station will prevent 315,000 tonnes of CO2 emissions a year.
Different types of CSP electricity generation and methods of heat storage have been chosen to ensure that the power stations perform optimally and cost-effectively in the different sites, explains Van Heerden. “That’s the beauty of Abengoa,” he says. “The company commercially operates many different technologies and we have drawn on this experience.”
In terms of government’s REIPPPP, the two power stations must be up and running by mid-2015.
CSP’s key advantages
The power stations, says Van Heerden, amply demonstrate two key advantages CSP has over other forms of renewable energy being developed in South Africa. These are:
· CSP’s peak-load electricity generation capability, which can support the national utility, Eskom, to meet demand; and
· CSP’s job creation potential, which is greater than other forms of renewable energy. Van Heerden points out that the Abengoa CSP power stations counted for only two of the first 28 projects under the REIPPPP, but will generate 20% of the permanent jobs generated by the projects.
In response to government stipulations that local content in REIPPPP projects must increase in order to boost job creation and develop a green economy sector, the amount of local content in CSP projects selected in the first two rounds of the programme has already risen from 21% to 36%.
However, like most other developers, Van Heerden points out that high levels of local content will only become more feasible if CSP is deployed at a larger scale. This will give manufacturers the market assurance and economies of scale they require to tool up to meet growing local demand and possibly to export components.
Nevertheless, says Van Heerden, Abengoa will endeavour to procure as much as possible locally. Supplies and services for civil works and such structures as the power tower and power blocks are being procured in South Africa. The company undertaking the two projects’ engineering, procurement and construction (EPC) is actively looking for more South African suppliers. Abengoa has also asked business associations in Upington and Pofadder to draw up a data base of local suppliers in order to determine what can be procured in areas where the power stations are being developed.
In addition, says Van Heerden, Abengoa is investigating, through its subsidiary Rioglass, the possibility of setting up in the Northern Cape a plant to manufacture mirrors, or heliostats, used in the CSP power tower system. When parabolic trough installations in South Africa extend to 500MW, local manufacturing of the more complex curved glass will become feasible.
An item that cannot be procured in South Africa is the salt used to store heat energy. This consists of a mixture of sodium and potassium nitrates which is found only in Chile and Israel.
Local and economic development
A community trust in Upington and one in Pofadder hold 20% of the CSP project in its area, with Abengoa owning 51% of the projects and the IDC 29% as part of its mandate to support development of the green economy.
The IDC is funding on favourable terms the holdings of the community trusts, which will use dividends to buy their shares and fund social and economic development projects. In addition, the community trusts also own 8% of the EPC company.
Van Heerden says Abengoa is working closely with the community trusts and other stakeholders, such as municipalities, business forums and non-government organisations with projects in the area, to determine how to develop full value from investment in the areas.
The Bokpoort CSP power station
The Solucar Complex operated by Abengoa, which is buildinbg South Africa’s first two CSP power stations. Solucar is the largest solar complex in Europe. Located just outside of Sanlúcar la Mayor, Seville, this solar thermal and photovoltaic installation complex currently has 183 megawatts (MW) in operation. It will have a capacity of approximately 300 MW, using CSP tower, parabolic trough and photovoltaic technologies.
South Africa’s third Concentrated Solar Power (CSP) plant will be able to approximate a coal-based power station’s ability to generate electricity around the clock.
The R4,5 billion Bokpoort CSP power station under development in the Northern Cape will include a facility to store for up to nine hours heat energy accumulated during the day. The power station will be able to use the stored energy to continue generating electricity for the national grid in cloudy periods and at night, including during evening peak demand time.
The developers hope that the new plant will create greater confidence in government to view CSP as a key contributor to South Africa’s energy supply and to increase substantially the relatively small amount of CSP-generated electricity it has earmarked to buy over the next 20 years.
Government has allocated to CSP only 1 200 megawatts (MW) of the 18 900 MW of renewable energy it has scheduled from South African power producers under the Integrated Resource Plan, which projects South Africa’s energy requirements until 2030. 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 he CSP industry, argues that CSP’s ability to dispatch peak demand electricity distinguishes CSP from other renewable energy technologies, such as wind and PV which are restricted by natural and weather conditions.
“We see development of the Bokpoort plant as an opportunity to prove that CSP is a base load technology,” says Michael Goldblatt, a director of Solafrica which is part of the consortium developing the plant. “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.”
He adds that Eskom, the national utility that will buy renewable energy, will welcome Bokpoort because of the stable and predictable electricity it will be able to supply.
The Bokpoort CSP power station is named for the 6 000 hectare farm on which the developers hope to start construction in early 2013. The site is situated near the town of Groblershoop, about 100 kilometres south east of Upington, the regional hub of a solar energy industry being developed in the Northern Cape, which has among the world’s highest solar radiation, or direct normal irradiance.Developers and shareholders
Bokpoort CSP is 40%-owned by the Saudi Arabia-based ACWA Power International group, which is the lead developer and operator in partnership with Solafrica. The state-owned Industrial Development Corporation (IDC) has taken a 25% direct stake as part of its mandate to support development of a green economy.
The IDC will also fund on favourable terms the acquisition by a local community trust of a 5% share in the project, and another 5% stake for LoveLife through its investment manager, Kurisani. LoveLife is South Africa's largest national HIV prevention initiative for young people.
A further 13% stake is held by black economic empowerment investment group Lereko which has among its directors former North West province premier Popo Molefe and former environmental affairs minister Valli Moosa. Lereko Metier Sustainable Capital holds a 1,5% share. The remaining 10,5% is held by two foreign development finance institutions.
Goldblatt says Bookpoort CSP is effectively 30% black-owned, which exceeds the requirements of government’s Renewable Energy Independent Power Producers’ Procurement Programme.Design
The Bokpoort power station will be based on the parabolic trough design in which the sun's energy is concentrated by parabolically curved, trough-shaped reflectors onto a receiver pipe running along the inside of the curved surface. This energy heats oil flowing through the pipe, and the heat energy is then used to generate electricity in a conventional steam generator. Of the 36 operational CSP power stations worldwide, 23 are parabolic troughs.
Together with 9,5 hours of storage, the 50 MW plant will have the capacity to supply the electricity needs of a town the size of Upington, which consumes close on 40 MW. Allowing for down time, the plant will have on average a capacity factor of upwards of 50% which is superior to both wind and solar PV plants by a significant margin.
The plant will take up less than 300 hectares of the 6 700 hectare Bokpoort farm, which will be able to continue its sheep and game farming alongside energy production. Among key reasons for selecting the site, explains Goldblatt, are that solar radiation in the area is some 30% higher than in Spain, which has the world’s largest concentration of CSP plants; an Eskom sub-station is situated on the farm, enabling cost-effective access to the national grid; and the Orange River is just 12 kilometres from the site.Jobs
Bokpoort CSP will employ about 660 people during construction, and will have a permanent staff of about 48 to undertake operations and maintenance, with a third being highly skilled and the balance being made up of artisans and unskilled workers.Local content
With government pushing for as much local content as possible in renewable energy plants, Bokpoort CSP will be able to source at least 42% of its supplies and services in South Africa. Government’s targeted 60% to 70% local content in renewable energy plants can only be achieved if it permits large scale CSP deployment, explains Goldblatt. This will give local manufacturers and service providers a guaranteed market and enable them to take advantage of economies of scale, which could also open export markets.
CSP parabolic trough equipment which cannot be sourced locally now or probably in the near future include turbines, power blocks, receiver tubes and a special type of salt which is used in molten form to store heat. Curved reflectors, or mirrors, which concentrate the sun’s energy and make up a significant proportion of overall costs, could be manufactured locally if there was sufficient demand, but need to be imported at this stage.
Construction will be undertaken by a consortium of engineering, procurement and construction contractors made up of three leading Spanish solar thermal companies, TSK, Acciona and Sener, and the South African company Crowie Concessions.
Social and economic development
Dividends accruing to a community trust with a 5% shareholding in Bokpoort CSP will be invested in development of social projects, such as health and education facilities, within a 50 kilometre radius of the Bokpoort CSP site. This covers about 30 000 people in the !Kheis Local Municipality which includes Groblershoop and several small rural communities. As examples of the need for facilities, Goldblatt says there is no permanent clinic in the area and schools need to be upgraded.
In addition, 1.7% of turnover will be invested in two initiatives. LoveLife will undertake a programme involving an Aids awareness and prevention campaign, and establishment of a youth health clinic, community radio and amenities such as sports facilities.
A second programme, focused on local economic development, will be based on further development of an existing initiative to develop commercial farming in the area to promote the entry of historically disadvantaged farmers.
“This is a very sparsely populated area with very little economic activity,” says Goldblatt. “These initiatives will have a huge impact on the lives of people there. In addition, the power station will offer opportunities for local people to supply goods and services ranging from transport to food and catering.”
Solafrica directors Marc Immerman (top) and Michael Goldblatt (bottom)
with project manager Nasi Rwigema.