California Imperial Valley

There are two general geothermal resourees, dry (steam) fields and wet (brine) fields. More than 800 MWe is being produeed from sueh dry geothermal steam fields in Northern California. The wet fields usually eannot be used in this manner and Rankine eyele-type systems, ealled binary plants, are being eonsidered at sueh loeations. At the wet fields found in the Imperial Valley of Southern California, the geothermal fluid is a 250°C brine, whieh does not lend itself for use in eonventional steam turbines. 

The first commercial power plant to burn cattle manure to generate electricity was established in the Imperial Valley of southern California in 1987. The plant had a capacity of about 17 megawatts and supplied electricity to 20,000 homes. The manure is burned to produce steam for the generator. 

Ten University of California field stations located throughout the state (Figure 2) allow for the study of the evaporation beds under several climatic and design variations (Table I). All the evaporation beds were sampled except the one located farthest away, at the Imperial Valley station. The evaporation beds vary In temperature range and annual precipitation, and In such design considerations as size, soil depth, soil pH, the presence or absence of storage tanks, a roof over the bed or slab area, and whether or not the soil Itself has been amended with hydrated lime. The beds also differ In the specific pesticide wastes disposed, and the longevity and Intensity of use. 

The present cost of a 25 kW, 944 ft2 stand-alone prototype unit is about 150,000. This price is likely to drop as production volume rises. Stirling Energy Systems, Inc., is operating a six-dish test unit at Sandia National Laboratories and has contracts for full-size power plants. Their construction started in 2008 and will be completed in 2012. A 500 mW plant will be built at Victorville, California, in the Mojave Desert for Southern California Edison. This construction is estimated to take 3-4 years. The plant will consist of 20,000 dishes over a 4,500 acre area. Another 300 mW plant will also be built at Imperial Valley, Calexico, California, for San Diego Gas and Electric on an area of 2,000 acres. 

Alkalization occurs as well with the salts left behind in the course of intensive irrigation. Growers in those areas of the Imperial Valley in California suffering from alkalization have had to install drainage tiles at shorter and shorter intervals over the years in order to prevent the buildup from reaching ruinous proportions. 

In some cases, misconceptions led to the unnecessary use of pesticides. Cotton farmers in the Imperial Valley of California saw Lygus hesperus on the cotton and sprayed, even though work at the nearby experimental station showed the insects did not lower the yield of cotton.361 By ignoring this and other recommendations based on local research, the industry almost collapsed before it was revived by the adoption of integrated pest management. Vietnamese rice farmers sprayed leaf-folders until they were shown by demonstration plots that the insects made no difference on the yield.362... 

As to the size of farms, the 1964 census shows the average farm was about 350 acres. Recent studies in California, as reported in the San Francisco Chronicle, concluded that 640 acres is more realistic as an efficient and competitive enterprise. However, in certain crop areas such as the Imperial Valley of California, up to 1,500-2,000 acres are needed and in the Palouse area of Eastern Washington, 1,600 acres are considered the best size for wheat and pea farms (14). 

In 2003, the geophysicist Vladimir Keilis-Borok, director of the International Institute of Earthquake Prediction Theory and Mathematical Geophysics in Moscow issued an alarm for an upcoming earthquake of magnitude 6.4 or greater within a 12.440 square miles area of southern California that includes portions of the eastern Mojave Desert, Coachella Valley, Imperial Valley (San Bernardino, Riverside and Imperial Counties) and east-... 

Most data on the relation of temperature to aflatoxin formation have been obtained with A. parasiticus. Aflatoxin contamination of cottonseed by A. flavus in the field occurs primarily in low-altitude areas of Arizona and the Imperial Valley of California and not in the hot and humid Southeastern States. Chronic field contamination of cottonseed apparently requires daily mean temperature of 34 C or above (T.E. Russell, personal communication). The significant difference between Arizona and the Southeast cotton areas is the high night temperatures of 32-34 C in Arizona. 

II25] Joyner, W. B. and Boore, D. M. Peak horizontal acceleration and velocity from strong-motion records including records from the 1979 Imperial Valley, California, earthquake. Bulletin of the Seismological Society of America 71(6) (1981), 2011-2038. 

Tait, C.E. (1908). Irrigation in Imperial Valley, California. Its problems and possibilities. 

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