Thursday, April 3, 2008

Bill Boyne: It's time to get serious about solar energy

4/3/2008 8:33:31 AM

You can't beat the sun as a source of energy.

That's the view of those who are building thermal solar energy plants in this country's western deserts.

Thermal solar energy is produced by building long lines of mirrors in the desert to focus sunlight on large steel pipes filled with oil. The sunlight heats the oil, which is then passed through water to produce steam and the steam is used to run generators, producing electricity.

It is not a new process, but it is gaining popularity as the need for renewable energy sources becomes more urgent.

A new plant, Nevada Solar One, has been built near Boulder City, Nev., 20 miles south of Las Vegas, by Acciona Solar Power, a Spanish firm. Ten other plants of this type are being planned in California, Arizona and Nevada.

When completed, the Solar One plant will be capable of producing enough power for 14,000 households. It is the third largest thermal solar power plant in the world.

Backers of thermal solar plants say the western deserts receive enough sunshine to provide the power to meet the needs of all 50 states. However, that is impractical because of the long transmission cables that would be needed.

Industry experts say that the Nevada plants will produce electric power at a cost of 15 to 20 cents per kilowatt hour and they believe that, in time, this cost can be reduced to 10 cents. New coal-fired plants produce power at a cost of 7 cents per kilowatt hour, but the thermal solar plants are preferred because they do not produce carbon dioxide or other greenhouse gas emissions.

Eight thermal solar plants are under construction in Spain, Algeria and Morocco and others are being planned in Mexico, Israel, South Africa, China and Egypt.

Most people are more familiar with solar voltaic panels, but that process is designed for other uses.

The Nevada Solar One plant covers 400 acres and has 184,000 mirrors. The mirrors are designed to turn slowly, following the sun across the sky, in order to deliver the maximum amount of heat for creating steam.

The reflected sunlight heats the oil to 400 degrees Celsius (about 750 degrees Fahrenheit). If the heat is not needed immediately, the oil is transferred to a vault of molten salt, where the heat can be stored for later use.

Gilbert Cohen, senior vice president of Acciona Solar Power, has said the western United States could produce 4,000 to 40,000 megawatts of electric power, enough to serve 1 million to 4 million homes.

Jose Manuel Entrecanales, chairman and chief executive officer of Acciona Solar Power, was the speaker at the dedication ceremonies for the plant in February. He said, "Nevada Solar One represents our bid to excel in new technologies to produce clean and sustainable energy, with an emphasis on economic viability, technical competence and the capacity to be replicated in locations around the world."

Acciona Solar Power plans to reduce the world's carbon dioxide emissions by 220 million tons in the next 23 years. This is a full 1 percent of the reduction of 18.4 billion tons needed from the world's power production industry by the 2030 deadline set by the Intergovernmental Panel on Climate Change.

The European Solar Thermal Industry Federation recently announced a solar thermal action plan for Europe. Its goal for 2020 is to reach one square meter of solar collector area for every person in Europe -- enough to produce 320 gigawatts of solar thermal power. The plan also calls for regulations requiring use of solar thermal energy in new or remodeled buildings and financial incentives for solar thermal power plants.

The United States needs a similar action plan to take advantage of one of the cleanest and most productive sources of electricity that can be found.

Boyne is a retired publisher and editor of the Post-Bulletin. His column appears weekly.

No comments:

Post a Comment