solar farms for 
sub-Saharan Africa

AEG Power Solutions South Africa has
 partnered with local solar developer
 RetoSolar to build large grid-connected solar farms, which aim to generate an alternative source of power in sub-Saharan Africa.
AEG Power Solutions business development director Trevor de Vries says that the company and RetoSolar have identified up to 20 large solar farms, ranging 
between 5 MW and 20 MW, in South Africa, Botswana and Namibia.
The company’s alternative energy division’s main focus is to manufacture inverters for solar and wind farms. These new PV250 and PV500 solar inverters can also be used for utility-scale applications on industrial roofs and for ground-mounted installations.
“One of the main features of the inverter is its power stack with advanced peripheral equipment, which allows dc voltages to reach up to 1 000 V dc. Projects with thin film modules will benefit significantly from this wide dc range,” he says.
Further, De Vries says that solar farms are a new technology in South Africa. “In countries such as Spain, France and Germany, solar development is more advanced than in South Africa, as it is not economically viable 
if the power cannot be sold back to State-owned power utility Eskom.”
He adds that Eskom plans to implement a renewable-energy feed-in tariff for energy that is supplied to the power utility. It is 
estimated that 3,94c/kWh will be paid for photovoltaic solar power.
Solar development initiatives in South Africa aim to supplement Eskom’s power supply, which is reaching capacity and is not meeting the country’s demand. “Therefore, solar farms are being developed to produce more power to supplement the national power grid and drive efficiency.”
De Vries explains that a typical 5-MW solar farm can cost about R150-million to R200- million to build and, if a farm produces less than 1 MW, it is difficult to attract investors, as there is no return on investment.
Another significant challenge is that solar farms are also time-consuming to construct and solar power is based on available radiation, so a solar farm is only productive for a few hours a day. “All solar projects currently in development are in design stages. AEG’s first solar farm is expected to be completed by the end of 2011.”
Further, De Vries says that the company is also involved in various green building projects, which aim to improve energy efficiency. “There has been a significant trend among businesses to invest in solar and other energy efficient systems to generate power that can be reused within the company,” he adds.
Companies install these systems in order to reuse the power to feed emergency lighting, water pumps and nonessential power systems in the building. “Converting power into usable power is very expensive; however, companies invest in energy efficient systems to drive green buildings and reduce their carbon footprint,” he says.