ACHRNEWS

July 31, 2007: Major Solar Power Plant Uses Dow Heat Transfer Fluid

July 31, 2007

MIDLAND, Mich. - DOWTHERM™ A heat transfer fluid from The Dow Chemical Co. is helping the world’s third largest solar power plant, Nevada Solar One, convert sunlight into electricity. Dow Performance Fluids recently delivered several million dollars worth of the fluid to Solar One’s Nevada desert location. The large quantity of material will play a critical role in the operation and generation of renewable electricity at the new solar plant.

Solar energy collectors generate a great deal of heat. In the parabolic collector system, the role of the heat transfer fluid is to collect this heat energy and transmit it to the power generating equipment where the steam to drive the electricity generating turbines is made. DOWTHERM A fluid is designed for systems that use liquid phase or vapor phase heating. The material is a mixture of two compounds, biphenyl and diphenyl oxide. Both substances possess the high-temperature thermal stability needed to collect and transport heat from the sun to the power generating station.

In addition to Dow’s capacity to supply Nevada Solar One with a large amount of material in a short amount of time, the company also provided the logistical support needed to transport the DOWTHERM A fluid. Seventy-two ISO-containers with fluid heated to 130°F were sent to the site in just five days.

“There are very few companies that have the ability to fulfill a shipment of this size while also meeting the necessary requirements,” said Steven Stanley, Ph.D., global business director for Dow Performance Fluids. “There are other, similar solar opportunities coming on-line in Spain and Mexico. With global supply capabilities, we believe Dow is well positioned to perform in those countries just as we have in Nevada.”

Nevada Solar One uses parabolic mirror troughs as thermal solar concentrators to heat tubes of liquid DOWTHERM A. The heated material generates steam to power electric turbines. These solar receivers are specially coated glass and steel tubes. About 19,300 of these four-meter-long tubes are being used to generate 64 MW of electricity - enough electricity to power about 45,000 average homes for a year. Plants like Solar One are said to be ideal for areas like the southwestern United States that use a significant amount of electricity to run air conditioning. With the land and sun resources available in places like Nevada, and state regulations mandating that at least 5 percent of electric power come from solar energy by 2015, Dow said it is likely that more plants like Solar One will be built.

For more information, visit www.dow.com.

Publication date: 07/30/2007