Solar energy collectors generate a great deal of heat. In the parabolic collector system, the role of the heat transfer fluid is actually 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 suitable for systems that use liquid phase or vapor phase heating. Its 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.
Dow provided the logistical support needed to transport the fluid. Seventy-two ISO-containers with fluid heated to 130°F were sent to the Nevada Solar One site in five days. 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 mega watts of electricity enough electricity to power about 45,000 average homes for a year.
Plants such as Nevada Solar One are considered ideal for the Southwest, an area that uses a significant amount of electricity to run air conditioning. With the states land and sun resources and with state regulations mandating that at least 5 percent of electric power come from solar energy by 2015 it is likely that similar plants will be built.
More information about Dow can be found at www.dow.com.