Doug Dixon of EPRI presented information about hydropower and fish-friendly turbines at last week's renewable energy fest at the Electric Power Research Institute.

More than 7 per cent of U.S. electricity and 75% of renewable electrical energy in the U.S. comes from hydropower according to Dixon of EPRI.  Compare that with the sub-1 per cent sliver of energy provided by solar.  According to the most recent DOE figures, there is about 80,000 megawatts of conventional hydro capacity and 18,000 megawatts of pumped storage.

Water is the leading renewable energy source used by electric utilities to generate electric power.  Hydro power is cheap, dispatchable, storable, and produced with no fuel combustion.  As with all energy sources, there is an environmental price.  Aside from the profound physical impact of damming and diverting huge waterways, fish suffer immensely - both from the difficulty in traveling upstream (if you're a salmon) and from the utter carnage of dodging turbine blades.

In 1996, DOE, EPRI and industry began a multi-year effort to develop ‘fish-friendly’ turbines for hydroelectric projects that are greater than 90% efficient and reduce fish mortality to 5% or less. By 2001, the research produced two turbine designs. The first, designed for large rivers, is currently being tested in the Columbia River. The second, designed for smaller rivers, is called the Alden/Concepts NREC turbine and features a helical-shaped runner with only three blades.  The Alden turbine has no gaps and by virtue of its larger size, turns slower, which means less impact on fish.  Up to 98 per cent of fish survive passing through the Alden turbine.
It is extremely expensive to protect fish.  As a testament to the resources and money devoted to fish safety by the energy industry:

  • Removable weirs costing $50 million to $70 million each are in use to channel fish away from turbines
  • The $52 million Puget Sound Energy floating surface collector or "Gulper" captures juvenile salmon out of dam's way and transports them in a half-hour tanker-truck ride downstream for release into the Skagit River (see photo).

Better turbine designs like the Alden turbine means much better fish survival and eliminate the need for weirs and busing fish to less dangerous neighborhoods.



Tags: dams, fish, hydropower