GROUNDWATER USE ASSOCIATED WITH SOLAR ENERGY DEVELOPMENT IN THE SOUTHWESTERN UNITED STATES

Utility-scale solar energy development under consideration on public lands in the southwestern United States requires analysis of potential environmental impacts. Water requirements to support various solar technologies – for cooling systems and/or equipment cleaning – are an important factor because of water rights and ecological water considerations in this arid region. Impacts were analyzed for the Final Programmatic Environmental Impact Statement for Solar Energy Development in Six Southwestern States, released in July 2012 by the Bureau of Land Management and the U.S. Department of Energy. As a follow-on study, groundwater modeling analyses were conducted to evaluate the drawdown associated with a range of development levels and technologies at a select set of solar energy zones. The approaches of these models ranged from one-dimensional analytical models to three-dimensional numerical models which were in some cases derived from existing federal agency modeling efforts and in other cases were newly constructed using public information. Results indicate that the impacts on water levels depend strongly on the water demand of the considered solar energy technology.