Statewide Assessment Of Water-Related Energy Use

The Pacific Institute’s Water to Air Models allow water managers to quantify the energy and air quality impacts of their management decisions. These impacts are increasingly relevant to water decision-making, as energy intensive options like seawater desalination and inter-basin transfers are weighed against options that are usually less energy intensive, such as use-efficiency, conjunctive use, or wastewater reclamation (recycling). This report presents the results of our preliminary application of the model to the entire state for the year 2000. The results will be refined in subsequent research. Although uncertain, the preliminary results suggest that water-related electricity, natural gas, diesel fuel, and carbon dioxide emissions amount to about 20%, 10%, 4%, and 8%, respectively, of statewide energy use or emissions in these categories in year 2000. The average energy intensity of water use was estimated at about 2,029 equivalent kWh (a measure of total, not just electric, energy use), including 1,363 actual kWh of electricity per acre-foot of water delivered to customers. Carbon dioxide emissions intensity was estimated to be about 1.03 metric tons per acre-foot delivered to customers. Water delivered to customers in year 2000 was estimated at slightly less than 38 million acre-feet. Energy and emissions intensities vary considerably depending on many factors such as geography, type of water system, and customer uses of wate