United Press International
Aug. 24, 2006
Everyone agrees that solar power is too expensive, but when the consumers in question have high unemployment and poverty rates coupled with access to the cheapest electricity in the world, the question of price becomes essential.
South Africa's only utility, Eskom, is considering building a 100-megawatt concentrator solar thermal power station in the Northern Cape province on South Africa's west coast. It would be the country's first solar energy project, as well as its first project in the field of renewable energy.
But the rise in price that would come with adding solar has the potential to harm poor South Africans.
"It really is a conundrum," John Ledger, the chairman of the Sustainable Energy Society of South Africa, told United Press International in a telephone interview.
South Africa's abundant supply of coal means customers pay 2 cents per kilowatt hour for its electricity. Since Eskom developed technology to use even low-grade coal with a high ash content, a low price has been virtually guaranteed.
By comparison, the average price for electricity in the United States is 11 cents per kilowatt hour.
Ninety percent of the electricity comes from coal burning, and there is one 1,800-megawatt nuclear plant as well, Ledger said. One half of 1 percent of the total energy produced is from renewable sources, according to Louis van Heerden, an Eskom corporate specialist on renewable energy.
"In 1994, after a democratic government was elected (for the first time), the government took on a massive rollout of electrification," Ledger said.
Many black South Africans living in rural regions or in the shanty townships around cities had been living unconnected to the grid under apartheid.
Now, Ledger said, the poor "enjoy the benefits of light, television and radio, but they don't use electricity for cooking because it's too expensive."
Instead, many families cook over coal fires inside their homes, Ledger said. The resulting smoke is highly toxic and causes "serious health problems and respiratory diseases, especially in children," Ledger said.
Of course, "we don't include environmental costs in the price of electricity," he said.
Solar energy proponents worldwide say that if environmental costs were factored, solar would come out to be the less expensive power source by far -- but this is usually a measure of costs to society rather than costs to individual consumers.
South Africa, the Sahara Desert, Saudi Arabia, central Australia, Peru and Bolivia have higher daily averages of effective sunshine than other places in the world that have succeeded with solar, such as the southwestern United States.
Professor Thomas Harms, of the University of Stellenbosch's department of mechanical engineering, did an electricity generation cost comparison for South Africa's Engineering News. He concluded that competing with a coal-fired power station is virtually impossible.
However, looking at morning and evening peak loads changes the whole picture, Harms said in the report.
"A shortage of peak power-generating plant capacity in South Africa means that base-load plants have to run intermittently at, say, 12 cents per kilowatt hour. This is an arbitrary figure and depends on the load factors, such as during which part of the day the coal plant feeds power into the grid -- the shorter the period, the more expensive it is."
Therefore, a solar power station in South Africa would have to incorporate energy storage to deliver at these peak load times, Harms told the newspaper.
The solar thermal tower design Eskom is considering is particularly good at energy storage, Harms said. In this design, an array of mirrors reflect sunlight onto a central tower several dozen meters tall. The resulting heat powers turbines, usually by creating steam.
Eskom's van Heerden told UPI in an e-mail that the utility would most likely act as a project manager in building the facility, but that the project would be subject to an open tender, with an emphasis placed on using the local workforce.
Ledger said he's optimistic the project will go through, and added that there is also a "big interest" in solar water heating.
Van Heerden said that it was not possible at the moment to speculate about the project's chances for success. "The current project phase concludes at the end of 2007, (and) the final investment decision will most likely be taken to the Eskom Board by February 2008," van Heerden wrote.
"It is estimated that the construction lead time will be three years," van Heerden said.
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