Dam Project is Much Neededby Staff
The Olympian, April 23, 2012
This is no simple undertaking: Rework of the six behemoth generating units in the dam's Third Powerhouse is expected to take 10 years at a cost of roughly $300 million.
In return, the electrical output from the dam will grow by about 240 megawatts, which is enough electricity to power about 240,000 homes.
This is a worthwhile project for the region and provides the Bonneville Power Administration with more options in its marketing and sale of power generated by the federal hydropower system on the Columbia and Snake rivers.
Hydropower is always in high demand. But in the world we live in today, the likelihood of new, gigantic, power-producing dams being constructed in the Pacific Northwest is next to zero. So it makes sense to squeeze as much electricity out of the existing hydroelectric dams by replacing aging generators, turbines and other equipment with more energy efficient models.
Energy gained through more efficient operation of the dams qualifies as a renewable resource under Initiative 937, the voter-approved measure designed to increase the amount of green energy supplied by the state's larger utilities. This is another indication that the Grand Coulee Dam project is the right thing to do.
The Third Powerhouse was built in 1974, so all six generating units installed there have far outlived their 25-year design life. The old units are leaking and showing their age in other ways. They need to be replaced in an orderly way, not as a reaction to some type of major equipment failure.
It takes about 17 months to replace each unit. The three smaller units rated at 690 megawatts will be replaced with 770-megawatt generators. The three larger units produce 805 megawatts and can't have their output boosted in a cost effective manner.
The original dam built from 1933 to 1942 featured two powerhouses. In the years ahead, look for renovations at the original powerhouses to also boost capacity at the Grand Coulee Dam.
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