Partners: Alliance for Water Efficiency, Pacific Northwest National Laboratory
This research project reviewed the technical savings and market potential of several alternative cooling tower technologies to save both energy and water in the ComEd service territory.
The Alliance for Water Efficiency (AWE) and the Pacific Northwest National Laboratory (PNNL) led a multi-utility-client cooling tower study, including ComEd. PNNL collected data on cooling tower water consumption and developed a Cooling Tower Estimating Model (CTEM) to determine cooling tower cooling demand and water consumption. Along with the CTEM, PNNL developed best practices for identifying water-cooled facilities and estimating their consumptive and non-consumptive water demands for cooling.
ComEd supported additional tasks to determine the water savings and energy savings potential of new and alternative treatment technologies for cooling towers and to identify potential barriers to implementing these technologies.
Results and Outcomes
Using the Cooling Tower Estimating Model that PNNL developed, the project team estimated that there are approximately 8,259 cooling towers in the ComEd service territory with a total water consumption of 4,684 million gallons/year and energy consumption of 152.6 GWh/year.
In phase 2 of the study, the project team reviewed eight alternative add-on cooling tower technologies and modeled their potential to save water and energy. They found that only three of the technologies showed promising water and energy saving potential: adiabatic coolers, water recapture systems and salt-based ion exchange treatment. The project team then performed an economic analysis of those three technologies and a review of potential market barriers. They determined from the results of a lifecycle cost analysis that the salt-based ion exchange was the only cost-effective technology with an estimated simple payback of 2.11 years and was found to have the lowest potential barriers to adoption in the ComEd market.