Desert Winds and Electrical Energy
The energy of the wind can be channeled into other forms of energy besides the energy used as an erosional agent. This is especially true of desert winds. Today, some desert wind is used to make electricity.
Wind velocity is affected by air temperature. When air warms and cools, it changes density, which creates air pressure differences that cause wind. In the desert, temperatures may range from 40 F at night to more than 120 F in the daytime. Because of this temperature fluctuation, wind is generally stronger in desert areas.
There are many windy areas in California. It is usually windier during the summer months when wind rushes in from cooler areas, like the ocean to replace hot rising air in Californias deserts.
In Southern California, the hot air from the desert goes up and out over the Coast Range, reaching seaward. When it cools off it descends and flows back toward the land and re-enters the desert through such loop holes in the Coast Range as the San Gorgonio Pass the old Puerta de San Carlos above Indio. The rush of wind through this particular pass is quite violent at times. For wind is very much like water and seeks the least obstructed path. Throughout the San Gorgonio Pass there are wind-eroded ledges attesting to the violent winds that pass through it.
The San Gorgonio Pass has Mt. San Gorgonio on the north and Mt. San Jacinto on the south. Both mountains are approximately two miles high. Mount San Gorgonio rises 11,499 feet. Mount San Jacinto is 10, 804 feet high. San Gorgonio has been described as the tallest hill in the United States, even thought it is a mountain. This is because its peak resembles the rounded knoll of a hill. San Jacinto has the fifth highest rock wall on the North American continent. With its feet in the blazing desert, it rises abruptly over 10,000 feet. The San Gorgonio Pass is the deepest pass in the continental 48 states. The pass opens up in the east to Cabazon and is the gateway to the desert.
The San Gorgonio Pass was a prime candidate for wind turbines as it is one of the three windiest areas of the state. California provides about 30 percent of the worlds wind-generated electricity. The San Gorgonio Pass has more than 3,500 wind turbines; many are massed on the floor of the Whitewater Wash (an ephemeral stream).
The desert wind phenomenon created by desert winds leaving and re-entering the desert area, the Coachella Valley, for example, did not occur rapidly. The San Gorgonio Pass was created by the San Andreas fault system. The San Gorgonio Pass is the easiest route into the coastal basin, since it has an easy grade. The eastern end of the pass enters the Coachella Valley at Whitewater Canyon. It does so as a well-formed gradual slope, and is about 1.5 miles wide measured between Windy Point and Whitewater Hill. The summit of the pass is at the west edge of the City of Beaumont, at 2,600 feet elevation. Nowhere is the pass a steep grade. From Beaumont, the pass slopes gently eastward for ten miles to Cabazon at 1,800 feet, and in another nine miles enters the Coachella Valley at 1,200 feet. The average grade is about 1.5 percent.
Nearly all rocks exposed in the pass represent alluvial fan deposits derived from the bordering mountains. These sedimentary rocks appear as a narrow band of low foothills along the north margin. Occasional exposures of the marine Imperial formation exist in thin and isolated beds, suggesting this was the most northward incursion of the ocean waters of the Gulf during Miocene time.
The body of the pass appears to be a thick fill of alluvial material of youthful age, laid down under similar conditions and contemporary with the Coachella Valley. Surface deposits consist of wind blown sand and alluvium.
It becomes easy to see how this particular geologic structure is being used as a wind farm.
The wind turbines that generate the electricity work because blowing wind spins the blades on the turbine. The blades are attached to a hub that is mounted on the turning shaft. The shaft goes through a gear transmission box where turning speed is increased. The transmission is attached to a high-speed shaft, which turns a generator that makes electricity. If the wind gets too high, the turbine has a brake that will keep the blades from turning and being damaged.
Although the geological age of the San Gorgonio Pass is in the millions of years, Californias great wind rush is relatively new and only about 20 years old. Both, however, are movie stars as the wind turbines on the Palm Springs side of the San Gorgonio Pass have appeared in several Hollywood movies.
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