Energy is the biggest cost for desalination plants, sometimes 50%, more than with importing water from elsewhere and much more than wastewater recycling. California has seventeen proposed desalination plants. San Diego has started construction of the biggest desal plant in the Western Hemisphere. California absolutely needs much more water, but where will the energy come from? On hot summer days California already faces the possibility of power shortages. This will be exacerbated by the San Onofre nuclear plant being closed, quite possibly permanently.
While the projects may ease water strains for area utilities, they’ll increase suppliers’ exposure to variable energy prices…
“While you may be improving your water reliability, you may be increasing your vulnerability to energy price changes over time.”
Energy and water are inextricably linked in California and the Southwest, where one of the biggest uses of electricity is for pumping water and large amounts of water are used for cooling in the generation of power. Seventeen desal plants would hugely help California’s ongoing water shortages. Running them though would require gigawatts of electricity that California simply doesn’t have, and this shortage is made worse by California’s plan to have 33% in-state renewable energy by 2020.