Creare LLC, a leading developer of energy and fluid systems, received a new contract from the US Department of Energy (DOE) to develop a low-cost desalination system driven by hydrokinetic power. Creare’s innovative technology can dramatically reduce the manufacturing and deployment costs of hydrokinetic power converters for ocean and tidal currents.  The low-cost water desalination project is one of several new grants awarded to Creare by DOE.

There is a growing shortage of fresh water in the U.S. and around the world.  Seawater desalination is a technically viable approach for increasing the supply of fresh water.  However, cost and environmental concerns have limited the adoption of desalination technology.  At the same time, tremendous amounts of power are potentially available from ocean and tidal currents.  Yet, high manufacturing and deployment costs and environmental concerns have made harvesting this power unattractive.

Harnessing Hydrokinetic Power for Desalination

There is thus an opportunity to develop a low-cost marine hydrokinetic (MHK) technology for harvesting power from water currents and desalinating water.  Creare’s MHK converter is essentially a high-pressure water pumping system.  The water flow and pressure generated by the converter can feed directly to a reverse osmosis desalination plant.  The innovative MHK converter design eliminates some of the key cost drivers for MHK systems.  The design features enable a dramatic reduction in manufacturing and deployment costs.  Use of renewable water current power instead of grid power reduces the environmental impacts of desalination.

Our innovative concept for MHK system generates pressurized seawater that flows into reverse osmosis desalination systems installed on nearby ships or barges.  The desalinated water moves to shore through a pipe or is stored on the platforms and then shipped to shore.  Brine is reintroduced to the current, where it diffuses quickly far from shore and with minimal impact on marine life.

During the project, Creare will design and optimize a commercial-scale MHK system to produce 100,000 cubic meters per day of desalinated water at minimum cost, and demonstrate critical hardware needed for high durability.  Creare will determine operating requirements for submerged bearings and seals, which are critical for system durability.  We will build prototype bearings and seals and measure their performance in proof-of-concept, accelerated life tests.  We will show that our MHK power system minimizes siting and environmental concerns.

This project builds on our past work developing hydrokinetic power systems.  Creare has already developed methods to analyze the behavior of hydrofoils in flowing water and identified design parameters that enable high-efficiency energy conversion.  We have also identified design features, fabrication approaches, and deployment concepts that minimize cost.