A startup developing technology that can clean water with low amounts of energy is quietly raising funds from some of Silicon Valley’s most-well-known venture firms. According to a filing, NanoH20 is raising $30.6 million and has closed on about half of that, or $14.9 million.
Investors in the company include Khosla Ventures, U.S. Renewables Group and Oak Investment Partners. Three years ago NanoH20 raised $15 million from Khosla Ventures and Oak Investment Partners.
NanoH20 has been working on nanoengineered reverse-osmosis membranes for desalinating water (cleaning it to use) that are supposed to be more productive and use less energy than traditional desalination membranes. The problem with standard reverse osmosis is that it is energy-intensive, and that makes it costly. Large amounts of energy, in the form of electricity, are used mostly to pump the water around and force it, under very high pressure, through membranes. The Pacific Institute estimates that electricity accounts for 44 percent of the cost of standard reverse-osmosis desalination, by far the single-largest expense.
NanoH2O says its membrane is much more permeable than prior attempts, which could translate to less energy needed to push the water through and lower facility-operation costs. The company has been working on desalination projects, including one with a water utility in the Cayman Islands called Water Authority Cayman and with the U.S. Navy Seawater Desalination Test Facility (SDTF) in Port Hueneme, Calif.
Investment in water tech in water-scarce regions is slowly starting to trickle in. Israeli water tech startups include AqWise and BioPetroClean, and Calera’s founder and former CEO Brent Constantz is working on a water desalination project in Monterey, Calif.