Water Savings Outweigh Higher Power Capacity in California’s Blythe Solar Project

On October 26, the U.S. Department of the Interior gave a final approval for construction on California’s Blythe Solar Power Project, what will be the largest solar power station in the world. After having been held under tight scrutiny in regards to the projects’ impact on the already seriously strained Colorado River basin, plant designs have switched to the use of dry solar thermal cooling instead of wet, cutting water requirements by 90% and clearing the way for the project's approval.

Despite a decrease in thermodynamic efficiency and power capacity in using dry cooling in place of wet cooling at the Blythe Solar Thermal Plant, plant officials “feel it’s worth it with the water savings.” Even with the reduction in efficiency, the Blythe Solar Project will have the ability generate approximately 1,000 megawatts of electricity, enough to power approximately 750,000 homes.

Although dry cooled solar thermal power stations consumes significantly less water than traditional electricity sources such as coal or nuclear power, even the small ratio or water use per megawatt output can negatively affect the already severely thirsty Mojave Desert region and nearby Colorado River basin. In efforts to offset any consumptive use of water coming from the Colorado River, which is currently at maximum allocation, the Blythe plant must either pay for conservation projects or irrigation improvements in the Palo Verde Irrigation District, fallow land, or remove tamarisks (a water-intensive invasive plant species), as reported in Circle of Blue: Waternews.

One additional and significant mitigational strategy which should be seriously considered in the Blythe Solar Project is the use of recycled water for the plant’s limited water needs for backup summer thermodynamic cooling and washing screens rather than relying on groundwater. Dependant on how effectively and honestly the power station offsets it’s Colorado River fueled underground water depletion, the Blythe Solar Power Project could pan out to be a fantastic example of how replacing traditional energy sources such as coal and nuclear power with renewable sources that have a minimal impact on water quantity and quality as a means to mitigate and adapt to climate change is possible, even in the heart of water scarce regions.