Water scarcity is a rapidly growing challenge in many parts of the U.S. and globally. One of the U.S.’s largest water users is evaporative cooling towers in power generation, data centers, manufacturing, and building heating, ventilation, and air conditioning, which consume over two trillion gallons of freshwater per year. The Department of Defense's (DoD) cooling towers and the cooling towers for the power plants that power DoD facilities consume an estimated 10 billion gallons per year. This project team plans to demonstrate a novel cooling tower plume capture technology to generate clean water from cooling tower evaporative losses. The technology would reduce the water footprint of DoD facilities, reduce wastewater production and treatment, enhance resilience to droughts, and reduce operational costs.

Cooling towers evaporate water to provide cooling. The water vapor that is generated in the process is discharged from the cooling tower and forms a visible plume of small liquid water droplets as vapor condenses by mixing with colder ambient air. The technology uses ion emitters to generate electrical charges and inject them into the water droplets. An electric field is then applied to attract the charged droplets to collection meshes where the water is captured and channeled back into the system for reuse. This project will focus on designing an embodiment of the technology that can be retrofitted on DoD cooling towers and measuring performance metrics such as water collection rate, water quality, and durability of the system. Performance metrics and a cost-benefit analysis will be generated to quantify the benefits of the technology for other DoD facilities.

Cooling towers are currently used with no attempt to reclaim any of the evaporation losses. The use of this technology would allow sustainable water usage by reducing water consumption for cooling. It would increase resilience by reducing dependence on water for cooling and power generation. It would significantly reduce the costs of water makeup, disposal and treatment. The technology would also generate high-purity water that can be used for other applications as a cheaper alternative to reverse osmosis to produce demineralized water. Finally, eliminating the plume would yield multiple safety benefits such as improved visibility in the vicinity of the tower and mitigation of icing on nearby roads and equipment.