Hydropower

New Wave-Pump Technology Hits the Water

A new pump system designed to turn salt water into fresh water when combined with desalination systems — and produce clean renewable energy when combined with hydroelectric systems — is currently being tested in the Gulf of Mexico, off the Texas coast.

To create hydroelectricity, the SEADOG ocean-wave pump captures energy from ocean swells or waves to pump seawater to a land-based holding area or water tower, where the water can be returned to the ocean through hydroelectric turbines. In addition, because the device pumps water to a reservoir, it can store salt water or desalinated fresh water in the form of potential energy to generate power on demand, even if the current wave regime during a particular period is too low to generate power. Developed by Minnesota-based energy technology company Independent Natural Resources Inc. (INRI), preliminary estimates based on SEADOG test results suggest that 1 square mile field of SEADOG pumps could generate anywhere from 50 megawatts to more than 1,500 megawatts (MW) of hydropower on average, depending on the wave regime. “Our sea trial in the Gulf of Mexico has exceeded our expectations and we’re confident our engineers have developed a new proprietary technology that serves as a safe, efficient system for gathering renewable energy from ocean waves,” said Mark A. Thomas, chief executive officer, INRI. SEADOG’s size, configuration and pumping capacity varies depending on the wave regime, height and frequency. During recent testing off the coast of Surfside, Texas, a single SEADOG pump experienced modest waves from 6 inches to 6 feet and consistently pumped a range of 15,000 to 40,000 gallons of seawater per day. “Going forward, we’re seeking actual ocean environments where we can place a wave-farm test field involving 14 to 200 SEADOG wave pumps. If the wave pump continues to perform as well as our sea tests have shown, we believe it has the potential to be a breakthrough for global energy production,” added Thomas. According to INRI’s calculations, the company’s wave-pump technology is capable of generating an average of 755 megawatts of hydroelectric energy for every 1 square mile pump field, assuming ocean swells averaging at least 9 feet. With swells of at least 5 feet, a 1 square mile pump field could generate approximately 242 MW. The lack of sufficient fresh water is a growing concern in many regions of the world and seawater desalination is increasingly essential. The state of Texas alone has more than 100 desalination plants. Energy consumption is significant in desalination, sometimes accounting for as much as one-third of the operating cost of desalinated water. Formed in January of 2002 by Thomas, the company developed and acquired the SEADOG pump technology from its inventor, Kenneth W. Welch, Jr., and co-inventors Curtis and Harold Rothi.