Texas firm will tap power of the Gulf

www.chron.com
Oct. 8, 2009

A Texas firm plans to use power generated by the Gulf of Mexico's waves to make its salty water drinkable.

Renew Blue Inc, says its project can address two global problems - climate change and scarce drinking water - by using clean energy to turn seawater to freshwater. The company has a lease from the state of Texas to place the facility in 25 feet of water about a mile off the coast from Freeport. It will use 18 specially designed, wave-powered pumps to send water over a wheel that will turn a small electric turbine. Power from the turbine will light the platform and run a 3,000-gallon-per-day desalination plant, said Doug Sandberg, vice president of Renew Blue's parent company, Independent Natural Resources Inc.

The desalinated water will be stored in a 30,000-gallon tank on the platform and then transported to shore, where it will be put in bottles made from corn-based plastic and marketed under the Renew Blue brand. The idea of generating electricity via ocean waves and currents has been around for several decades but is still in its early stages. Six% of U.S, electricity came from hydroelectric dams in 2008, according to the Department of Energy. Electricity generated that way - turning turbines with water backed up behind dams - is called hydropower, in contrast to hydrokinetic power, which uses existing currents and waves. A 2007 study by the Electric Power Research Institute found that the U.S, could develop at least 13,000 MWs of river- and ocean-based hydrokinetic power projects by 2025.

Several large projects have been proposed in recent years, but some have suffered setbacks. Earlier this year, for example, Pelamis Wave Power pulled its three large generators out of waters off the coast of Portugal, citing technical and financial difficulties. But Houston-based Hydro Green successfully placed a hydrokinetic water turbine just downstream from a hydropower plant on the Mississippi River in Hastings, Minn., this year that can generate up to 100 kWs. Conroe resident's pump Sandberg said the need for drinking water and clean energy are among major problems the world faces, and his company hopes its technology "will demonstrate a way to solve both those problems."

The offshore lease is the first the state has granted for the production of energy using ocean waves. The project will use a patented system called the Seadog, developed by Conroe-area resident Kenneth Welch Jr. A disk-shaped buoy rises and falls with the waves to move a piston that pumps water - either directly through a turbine or into an elevated storage tank that then releases water over a water wheel. The company and researchers from Texas A&M University's marine engineering technology department have tested the pump in the waters off Freeport and Galveston.

The project is designed to demonstrate the potential of the Seadog pumps, particularly for island nations or regions with stronger wave activity, such as off the coasts of Ireland or Africa, said Sandberg. Average wave heights along the Gulf Coast run about 3 or 4 feet, compared to 7 to 10 feet along Pacific and Atlantic coasts, Sandberg said. But testing in the relatively calm Gulf waters, where state and local officials have welcomed the work, gives the company a good showcase for potential customers.

The 18 Seadog pumps in the project off Freeport will be able to generate up to 60 kWs of electricity, depending on wave size. The desalination equipment only requires about 4 kWs, leaving power to run lighting on the platform, said Sandberg. INR, in business for seven years, has survived strictly on funding from "angel" investors, individuals willing to put their own money into the business. CEO Mark Thomas said the company will look to institutional investors for future funding or enter joint ventures on larger scale projects.

tom.fowler@chron.com