April 19, 2009
Solar Projects Face Challenge of Water Shortages
As electricity-hungry cities across the western U.S. look to cash in on one of the desert's few abundant natural resources "“ sunlight "“ some say they may be endangering rare desert animals as they compete for the area's rarest of resources: water.
Water has been traditionally used as the most cost-efficient means for cooling large-scale solar energy plants. As many energy companies have responded to Washington's call to up the scale of the countries renewable energy sources, they find themselves running into other environmental obstacles. The somewhat ironic situation has protectionists of natural resources up-in-arms over President Obama's plans for a greener energy industry in the America.
Companies aspiring to place solar energy plants in the area have found themselves confronted with highly-taxed aquifers and a legendary tangled web of legal and regulatory laws. Faced with such unattractive barriers, some companies are beginning to employ significantly more expensive air-cooled technology for cooling their miles of sun-reflecting mirrors in the deserts of Arizona, New Mexico, California and Nevada. Others are turning to solar dish and photovoltaic technologies that require neither steam engines nor cooling water, and which have become increasingly affordable in recent years.
The National Park Service is concerned about the environmental effects of the push for solar energy. Though it supports green energy in principle, it says it is worried about water shortages in areas like the Amargosa Valley of southern Nevada where the electric-blue pupfish lives in the aquifer-fed hot water cavern known as Devil's Hole.
"It is not in the public interest for BLM [Bureau of Land Management] to approve plans of development for water-cooled solar energy projects in the arid basins of southern Nevada, some of which are already over-appropriated," said Jon Jarvis, director of the Park Service's Pacific West Region.
A February e-mail from Jarvis prompted authorities in Nevada to ban new groundwater allocations within 25 miles of the pool in fear of driving the declining pupfish population to extinction.
Jarvis has encouraged the BLM not to issue water permits until it completes a thorough assessment of the solar programs next year. The BLM tried last year to suspend new applications, but gave in under increasing pressure from proponents of the green energy projects.
"Water is a big concern and the desert tortoise is a major concern, and the amount of site preparation is a concern," said BLM project manager Linda Resseguie. Authorities are carefully scrutinizing each of the more than 150 proposed projects before considering a "potentially irreversible commitment of lands," she added.
Energy companies are also struggling to find routes for their long-distance transmission lines through regions that are home to the threatened desert tortoise. The industry is concerned about a proposal in the works by Sen. Dianne Feinstein of California that would establish some 600,000 acres of nationally protected lands for a Mojave national monument in addition to the protected parks and military lands already in existence. The proposal would affect at least 14 solar and 5 wind energy proposals.
Kim Fiske of the energy firm Iberdola says that her company intends to use photovoltaic cells in the Amargosa Valley, but is examining the potential use of water-requiring systems for other sites. The Spanish-owned company has 12 applications under review in four states.
Photovoltaic systems convert sunlight directly to electricity through using a conducting medium. Compared to the traditional steam-turbine system that uses large volumes of water for continual cooling, photovoltaic technology requires only a negligible amount of water used to keep the solar panels clean.
"Water usage is becoming the larger issue. Some companies still want wet cooling and say it's less efficient than dry cooling, and they need 10 percent more land to get the same output," explained Peter Weiner, an attorney for the solar companies.
Because the proposals are still in flux, officials can't say exactly how much water would be required for the companies to carry out their operations. Hydrologists with the National Park Service estimated that almost 16.3 billion would be needed by applicants in the Amargosa Valley alone "“ enough to supply more than 50,000 homes with water for a year. As authorities have said that the valley could only support approximately half of that amount, several companies have either withdrawn their proposals or switched to photovoltaic models.
State authorities in California and Nevada have hinted that it may be a bit of a long shot for the companies proposing wet-cooled projects. The only two proposals currently under review in California would require minimal water use.
It's "a hot button for everybody," said Fiske in reference to the water situation. "Everyone is concerned about water. It's probably one of the biggest issues."
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