Public Power - November 2008 - (Page 38)

Hydro Power BY MARC HEQUET Damless What hangs underMinn., will findpowers a barge and 150 homes? Hastings, out. Houston hydro developer Hydro Green Energy LLC is testing its new hydroelectric technology at Hastings (pop. 21,000) in the tail race of the U.S. Army Corps of Engineers dam where the city operates a four-megawatt hydro plant. U.S. hydroelectric power remains firmly dam-based, with the Tennessee Valley and the Northwest key regions — but other areas now also draw attention, and not just for dams. Piggybacking on a dam’s existing license, Hastings’ would be the first dam-free generator feeding the grid. Its 200 kilowatts will be scarcely a spark compared with big base-load plants — but every megawatt can power 750 homes, and dam-free has its believers. Hydro Green raised $2.6 million from investors in April. Moreover, hydro fits the U.S. energy ideal. “We’re all looking for ways of producing clean energy and energy independence and controlling costs,” notes Linda Church Ciocci, the National Hydro Association executive director. U.S. hydroelectric capacity is 97,000 megawatts, about 9 percent of U.S. generating capacity. Natural gas, coal and nuclear account for 82 percent of nameplate. Still, hydro is the top renewable resource used for electric generation and its are prospects significant: A 2007 Electric Power Research Institute study estimates a potential for adding another 23,000 megawatts of hydro in the United States by 2025, including 10,000 megawatts from ocean waves and 3,000 megawatts from new Hastings-like technologies. Dam-based and dam-free hydro are essentially the same — water turns a turbine to generate electricity. The differences are noteworthy: Dams create “head” — a drop through which water falls to generate more power. During high or low water, however, dam-based hydro may operate less efficiently or shut down. 38 NOVEMBER-DECEMBER 2008PUBLIC POWER Norris Dam in Tennessee is the site of the Tennessee Valley Authority’s first hydroelectric project. TVA expects to add 526 megawatts of new hydroelectric generating capacity by 2016 — 10 percent of its existing capacity — without adding a dam. Photo source: Getty Images. Dam-free’s advantage is, well, it doesn’t require a dam. Hydro Green’s enclosed, horizontal-axis barge-mounted units with rotors 12 feet in diameter needs 22 feet of stream depth. Another plus: If it doesn’t work, yank it out. Hydro Green plans bargemounted units with collapsible gantries that can lift turbines out of the river for routine maintenance or outright removal. In theory, dam-free turbines work wherever current flows — and work best in deep and fast water. Turbines mounted on barges or pylons may power a few hundred households. Remote communities, take note: On Alaska’s Yukon River, costly diesel fuel runs local generators. Hydro Green has federal permits to study nine Alaskan sites. The firm might test smaller units in 2009, but its focus now is getting Hastings going. One of the issues is whether turbines harm migrating salmon and other fish. Dam-free hydro developers say the turbines turn slowly enough to allow fish to escape. Hydro Green’s 15 preliminary permits also include two on the lower Mississippi. A rival, Free Flow Power Corp. of Gloucester, Mass., is more ambitious still: It has permits to study 55 sites on the Mississippi River, from St. Louis downstream. Brookfield Renewable Power Inc. of Gatineau, Quebec, plans up to 265 megawatts at existing Mississippi dams from Dubuque, Iowa, to St. Louis. Brookfield owns the biggest generator on the Mississippi River, Louisiana Hydro at New Orleans, rated at 192 megawatts. Dam by dam down the Mississippi, however, what works requires study. “Each lock and dam has its own set of characteristics that can be very much favorable to hydro or very much unfavorable to hydro,” said Jeffrey Auser, Brookfield’s vice president for U.S. business development. Some cities want to develop hydro on their own. Quincy, Ill., has permits for three generators on the Mississippi. The cost is steep—$200 million. Quincy (population 41,000), with an operating budget of $30 million, has already spent $1.4 million. Yet Mayor John Spring says his City Council is all for it. With the three projects, Quincy hopes to have 52 megawatts of hyPUBLIC POWER

Table of Contents Feed for the Digital Edition of Public Power - November 2008

Public Power - November 2008 Contents Perspective 10 Questions Capturing Knowledge Before It Retires Jackson’s GIS Search Keeping a Job Journal Japan Tackles the Kyoto Protocol Getting to 20 by 10 Damless Hydro Power Earthquake: The Hidden Disaster For Engineers Safety For Governing Boards DEED Hometown Connections Parting Shot

Public Power - November 2008

For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.