Power plants are one of the biggest water users and most of it is used for cooling. We developed a technology that can recover large amounts of clean water from cooling tower plumes, reducing costs for plants and alleviating water stress for nearby communities
We are on the path to an extreme freshwater shortage and one of the US’s largest water consumers is power plants, which account for 39% of water withdrawals. Power plants typically use cooling towers, where some of the water is evaporated to cool the remaining water. The vapor is released into the atmosphere and lost, requiring new water to be added. The remaining water becomes more concentrated in salts and pollutants and needs to be treated, at an additional cost. For a 600MW plant, water losses are 700M gallons/year and cost the plant about $5M/year. We believe saving some of this water can have a profound global impact on water scarcity.
At MIT, we have developed a patent-pending product that can collect part of the water that is escaping from the cooling towers in the form of a plume to re-use it again. The product consists of charging electrodes at the outlet of the cooling tower that generate ions and charge the water in the plume, followed by a specially designed collector mesh that is placed on top of the cooling tower and on which condensed vapor droplets can be accumulated and collected with an imposed electric field. The deposited water is collected, directed to a temporary reservoir near the periphery of the collector, and then reintroduced back into the coolant loop for the customer to realize makeup water savings. This product can be retrofitted to any type of cooling tower or integrated into new cooling tower designs. The collected water is pure, distilled water and can also be used for other applications that require clean water.
We started this work trying to develop an efficient technology for fog harvesting to produce clean water in remote areas. Inspired by current designs of passive vertical meshes that collect fog at very low efficiencies (1-3%), we designed an active collector mesh using electric fields to reach collection efficiencies close to 100%. We then thought that applying the technology to cooling tower plumes, which are similar to fog but have much higher flow rates, would have a much bigger impact. We changed the design for this specific application (changed the electrodes, the mesh became spherical instead of vertical, etc). We developed a working lab-scale prototype and then signed a pilot with a 20MW power plant to build a full-scale version of the product. We then solved the structural design challenges of building a 20ft structure and we will be installing the product in a few months after thorough testing on the ground.
The most common cooling technology is wet cooling towers. There are water saving technologies in the market (mainly dry and wet-dry cooling) but they are prohibitively expensive to install and they are only used when imposed by local regulations. Our product is also the only one that can be retrofitted to existing towers. Our main competitor is thus the status quo, and we believe (based on our customers feedback) that with our business model of selling discounted water without requiring an upfront payment, there will be a strong financial incentive to adopt this product in this low-margin industry. With our patent portfolio, trade secrets, know how and first mover advantage, we believe it would be difficult for other players to compete.
We have started a company, Infinite Cooling, to commercialize this product. We have had great traction, winning a multitude of prizes and grants. We are currently finishing our first pilot on a power plant and we will start our next installation in the fall of 2018. Our goal is to finish prototyping and optimizing the product in 18 months and start scaling up to all power plants. Our longer-term vision is to turn this technology into an ultra low-cost desalination or purification technology for cooling towers that use seawater or wastewater.
Grand Prize – MIT $100K Entrepreneurship Competition - May 2018 Grand Prize – Rice Business Plan Competition - April 2018 Forbes 30 Under 30 - Energy - November 2017 First Prize – Harvard Business School Energy Startup Competition - October 2017 First Prize – DOE Cleantech UP National Competition - June 2017