Egypt tries Concentrating Solar Power

February 20, 2007 - Derek Sands - UPI

CAIRO -- Egypt may soon harness the same physics that a child uses to burn an ant with a magnifying glass, to generate electricity from the sun, a move that reflects the growth of Concentrating Solar Power technology worldwide.

Plans to build a 150 megawatt (MW) combined solar- and gas-powered electric plant near Cairo are part of a larger effort by Egypt, and others in the region, to expand their use of renewable energies, including solar, wind, and nuclear power.

The Egyptian project, set to be built in Kuraymat, 104 kilometers (65 miles) south of Cairo, will use parabolic-trough Concentrating Solar Power, a technology that has been used on a limited scale for more than 20 years, but has recently attracted attention in the Middle East because of efforts to reduce greenhouse gas emissions, and due to concerns over the future of petroleum supplies.

Worldwide consumption of renewable energy will almost double by 2030, according to the Energy Information Administration, the data arm of the US Department of Energy.

The Middle East is set to see the most dramatic change, with an average yearly increase in its renewable electricity generation capacity of more that 2.5 times the global average.

Although last year's high-level endorsement of nuclear power attracted headlines in Cairo and around the world, the Egyptian government has been pursuing other renewable sources of energy, most notably wind and solar. The Egyptian New and Renewable Energy Authority (NREA) hopes to provide 3 percent of the country's electricity needs through renewable sources by 2010.

The technology planned for Kuraymat uses rows of parabolic-shaped trough reflectors to focus sunlight onto a tube filled with circulating liquid, which is heated as it moves through a field of reflectors. The liquid, which will reach temperatures of about 400 Celsius (752 Fahrenheit) at Kuraymat, can then be used to power a steam turbine.

It is part of a larger family of solar technologies, called Concentrating Solar Power, which use a number of methods to generate electricity by concentrating the suns rays. Traditional solar cells, or photovoltaics, use sunlight to generate electricity directly. While Concentrating Solar Power can direct sunlight onto solar cells, it can also generate electricity through an intermediate, such as heating water to drive steam turbines.

Concentrating Solar Power is now almost exclusively being used in the US, but projects are underway in the Middle East, North Africa, Europe, and Latin America. Spain hopes to generate 500 MW of electricity from Concentrating Solar Power by 2010, and China is considering a 1000 MW plant that could cost more than $2 billion.

The $200 million project at Kuraymat, expected to be finished in 2009, will produce about 150 MW of power, 45 percent of which will be from solar parabolic troughs and steam turbines, the rest coming from natural gas turbines, according to the Egyptian NREA. Egypt had about 20 gigawatts (GW) of installed electricity capacity in 2006, according to the Egyptian government.

The solar project will not only provide the necessary electricity, but will also reduce carbon dioxide emissions by 38,000 tons per year, according to the NREA.

The power plant in Egypt, and others like it, uses natural gas turbines to supplement the solar-generated power, a method that allows a consistent supply of power at night and during bad weather.

"Combining [Concentrating Solar Power] with natural gas is common. There are 354 MW of parabolic-trough plants operating in California since the late 1980s. All of these plants are hybridized with natural gas. Solar provides 75 percent of the energy input to the power plant and gas provides 25 percent," according to Gregory Kolb, an expert on solar power for the US Department of Energy's Sandia National Laboratories.

And because Egypt, as well as much of the Middle East and North Africa, receives many more days of sunlight than Europe and North America, it is well suited for this type of power generation. Morocco, Algeria, and Iran are all building or planning parabolic-trough solar plants.

But North African countries are not the only ones that may benefit from their bounty of sunlight. Plans are under way that could provide Europe with 700,000 GW-hours per year of electricity from North Africa by 2050, through an interconnected electric grid, according to the European Commission's Directorate-General for Energy and Transportation.

While Concentrating Solar Power is a small portion of world energy supply, it has immense potential.

A 2006 report by Greenpeace and the European Solar Thermal Industry Association estimated that Concentrating Solar Power will contribute 600,000 MW worldwide by 2040, and that it will meet 5 percent of world demand.

In fact, the US Department of Energy has estimated that if 9 percent of the state of Nevada, an area of about 10,000 square miles, was covered in parabolic-trough solar plants, it could supply the electric power needs for the entire US. "Concentrating Solar Power has a very bright future," Kolb said.