MIT’s New System Harvests Fresh Water from Power Plants


A new system designed by Massachutes Institute of Technology (MIT) engineers have potential to provide a low-cost source of drinking water for cities around the world by capturing water evaporating from cooling towers of power plants.

The system will not only solve the problem of water scarcity in parched cities but will also cut power plant operating costs.

Principle behind the device

The device is based on a simple principle that when the air that is rich in fog is zapped with a beam of electrically charged ions, water droplets become electrically charged and hence can be drawn be drawn towards a mesh of wires. These droplets can then be drained down into a collecting pan and can be reused in the power plant or can be sent to a city’s water supply system.

Experiments conducted to test new system

The researchers first tested their system by building a small lab version of a stack emitting a plume of water droplets, similar to that of an actual power plant cooling towers and placed iron beam and mesh screen on it.

After getting the desired results, they are now building a full-scale test version of their system that will be placed on MIT’s Central Utility Plant (natural-gas cogeneration power plant that provides most of the campus’ electricity, heating, and cooling).

“The campus power plant tests will not only “de-risk” the technology, but will also help the MIT campus improve its water footprint,” said  Kripa Varanasi, associate professor of mechanical engineering, MIT.

“Typical 600-megawatt power plants could capture 150 million gallons of water a year, representing a value of millions of dollars. This represents about 20 to 30 percent of the water lost from cooling towers. With further refinements, the system may be able to capture even more of the output,” he added.

The system is the basis for a for a startup company called Infinite Cooling that won MIT’s $100K Entrepreneurship Competition last month.