SAN FRANCISCO, CA — When the inaugural Water Efficiency awards were handed out by Imagine H2O in March 2009, the nonprofit had already begun planning its next competition, and how it would expand the category of water-based startups to focus on the "Water-Energy Nexus."

As obscure as that topic might seem at first glance, their call for entries garnered more than 50 companies from around the world, all from entrepreneurs who've created businesses to reduce the energy needed to move and treat water and wastewater.

At the awards ceremony in San Francisco last week, three companies were honored with prizes. The first-place winner is Seattle-based Hydrovolts, which has created a technology to put floating hydro-kinetic turbines in canals to generate energy from the water that is already traveling in, for instance, irrigation canals on farmland.

Two runners-up were also awarded prizes last week: Blackgold Biofuels and FOGBusters, both of which generate energy by capturing the fat, oil and grease (FOG) from wastewater.

Together, these companies, as well as seven other finalists, are mapping a path to more efficient managing and transportation of water, while gathering renewable energy from the water in our everyday lives. The three winners will take home a combined $100,000 in cash and business and legal support, as well as gain access to Imagine H2O's network of partners, customers and financiers to help bring their products to market.

"Remarkably, these companies are turning cost-centers into profit-centers and unlocking important energy potential to make our water infrastructure more efficient and robust," Kate Gasner, Imagine H2O's Prize Manager, said in a statement announcing the winners.

Hydrovolts and the Energy Canals

With its hydrokinetic turbines, Hydrovolts has tapped into a broad and previously unrecognized energy source. Canals of varying sizes are in use around the world, from farms to water treatment facilities to hydropower plants, are generally managed by engineers, easy to access and have predictable water flows.

A single turbine can generate from one to 25 kilowatts of power, enough to power several American homes or an entire village in the developing world. The technology is easily shipped, easily installed and easily maintained, and can be used to power living areas or remote sensors, and in areas with rapid enough flows of water, can be scaled-up to generate utility-level amounts of energy.