Large-Scale Solar Energy Projects: Siting and Design Considerations in Desert Regions to Avoid Impacting National Park Water Resources

Solar energy is one of several energy sources being advanced to help achieve the broad national goal to develop a “new energy” economy and to reduce the nation’s dependence upon foreign oil and other green house gas emitting energy sources.  The National Park Service (NPS) supports the overall goal of increasing development of renewable energy resources such as solar.  The agency currently is working with other Federal agencies to insure that solar energy development doesn’t impact the water or other natural resources of National Parks.  The concern about water resource impacts to National Parks of solar energy development is greatest in the water scarce areas of the desert Southwest and, in particular, when “solar concentrating” or “solar thermal” power generation projects are proposed that require substantial amounts of water for cooling purposes. 
                           
The Bureau of Land Management (BLM) has received a large number of right-of-way applications for utility-scale solar energy projects on public lands in the deserts surrounding Death Valley National Park, Lake Mead National Recreation Area, and Mohave National Park and Preserve.  Many of the proposed projects would concentrate sunlight to heat water and then use conventional steam plants to produce electricity.  While this “solar concentrating” technology requires more land area than photovoltaic cell technology, it has the advantages of lower upfront costs and the ability to continue to produce electricity during periods when the sun is not shining.  The connection to water resources is that the use of conventional steam plants to produce electricity requires that the steam be cooled.  If the plants use conventional water cooling, considerable amounts of water may be consumed.  In desert regions, this would require using ground water as the water supply.  Conversely there exist air cooling technologies that, while more expensive, require very little water. 

The principle water resource concern to National Parks would be if the use of ground water for steam cooling resulted in lowering ground water tables currently supporting park springs, caves, or other water features such as Devil’s Hole, where maintaining water tables is critical to the survival of the endangered Devil’s Hole Pupfish. 

To help guide the development of utility-scale solar energy projects on public lands, the Bureau of Land Management (BLM) is preparing a Programmatic Environmental Impact Statement (PEIS).  The PEIS public scoping phase is completed and the proposed action seeks to adopt a best management practices approach for mitigating potential impacts, providing consistency and certainty to solar energy development, and expediting environmental analyses for site-specific projects in the future.  The current schedule calls for publishing a Final PEIS in the spring of 2010. The National Park Service is participating as a Cooperating Agency in the preparation of the PEIS, and will have the opportunity to advocate for management practices that avoid impacts to National Park water and other resources.