Turbines At Wanapum Dam Are More Efficient For Increased Power.
Eddies on the Mississippi River, dams on the Ohio River and turbines on the Columbia River are all getting a second look by companies, agencies and even cities as potential sources to increase the amount of hydroelectric power in the U.S.
“There is a resurgence of hydro,” says Linda Church Ciocci, executive director of the National Hydropower Association, Washington, D.C. Companies are upgrading systems to make them more efficient, looking at new technologies that would allow them to harness the energy of ocean waves, tides and river currents and adding turbines to unpowered dams. Only 3% of the nation’s dams are wired for power, Ciocci says.
The amount of power generated by hydroelectric facilities could increase, at a minimum, by 23,000 MW by 2025, according to a report released last March by the Electric Power Research Institute, Palo Alto, Calif. As much as 10,000 MW of the increase would come from ocean-wave-energy technologies and 5,000 MW from new conventional hydropower at existing non-powered dams. Traditional hydropower now generates about 77,000 MW, or 8% of the nation’s electricity during the summer, according to the Energy Information Administration.
Brookfield Power, a unit of Toronto-based Brookfield Asset Management Inc., has committed several billion dollars to building new hydro facilities in the U.S. over the next several years, says Jeff Auser, vice president of eastern U.S. generation development. The company is looking at 30 unpowered Army Corps of Engineers locks and dams in the Mississippi Valley and the eastern U.S. for their potential for new hydropower.
Other entities are focusing on in-stream technologies that use clusters of small turbines to generate electricity from the river currents. Manchester, Mass.-based Free Flow Power Inc., for example, is seeking 59 preliminary permits from FERC to develop up to 1,600 MW of power on the lower Mississippi.
Voith Siemens Hydro Power, York, Pa., is retrofitting hydro facilities all over the nation with more efficient turbines. One of the larger projects is in Grant County, Wash., where the Wanapum Dam on the Columbia River is getting a $150-million-plus makeover with 10 new fish-friendly, more-efficient turbines.
Because of the hydrodynamic improvements, the new turbine’s power is increased by 14%, with increases to water use efficiency averaging 3%, according to Grant County Public Utility District officials. At 80 ft of net head, the original turbine capacity is 90 MW, while the advanced turbine’s capacity is 112.5 MW, says Stuart Hammond, PUD hydroengineering supervisor.
Working with Voith Siemens, the utility developed a turbine that eliminates the gaps between the blades and the perimeter of the turbine by using a curved, or spherical, rather than a straight hub. The new turbine design also keeps the water flow equal when it leaves the turbine to reduce shear, the water differential that can injure or kill fish, Hammond says. Biological testing shows the improvement produces a 98% fish-survival rate.
Help Wanted
While the potential is great, Ciocci says conventional and new hydro technologies need more state and federal government help to get expensive technologies like Wanapum Dam’s advanced turbine project off the ground. The licensing process for a new hydro facility is more extensive and costly than the licensing for a new nuclear reactor, she says. With the broadening scope of hydropower, that aid becomes even more important to develop hydro technologies that can work also in lower-flow rivers, she says.
“Some technologies are not going to work within a water basin or system. Every technology has its unique characteristics,” she says. “Every site has its unique characteristics.”
