Grand Coulee Dam: growing, changing hydropower giant
Coulee Dam, Wash. — "This must be the most powerful penlight in the world," says Jerry Peterson. In his hand is a small device that looks like a pocket flashlight. With it he can start any of the i4 giant generators sending a huge surge of electrical power across the Pacific Northwest.
We are standing in what technicians call the "Star Trek" room deep in the bowels of Grand Coulee Dam. Here two technicians keep watch over 19 color television sets that tell them exactly what's happening in the world's largest hydroelectric dam.
Gradually, all major operations are being concentrated in this computerized operations center, a sign that things are changing at the Grand Old Lady of Northwest power dams.
This spring Grand Coulee reclaimed the title to being the world's largest power-producing dam, a claim it had previously surrendered to the 6,000 megawatt Krasnoyarsk Dam in Soviet Siberia.
That changed in April when the sixth and last generator went into operation in the dam's Third Powerhouse, giving Grand Coulee Dam an installed capcity of more than 6,200 megawatts, or the equivalent of about six large nuclear power plants.
Inside the cavernous Third Powerhouse are six of the largest electrical generators in the world, each one capable of putting out more power than the average coal-fired power plant.
An addition of two more 700-megawatt generators and two 500-megawatt "reversible pump generators" is being considered, which would bring the dam's total capacity to more than 8,000 megawatts.
That ought to assure the dam's preeminence, at least until a 12,000-megawatt superdam called Itaipu is built in South America on the border between Brazil and Paraguay.
Everything about Grand Coulee Dam is of Gargantuan proportions, even its mistakes.
For example, last fall a technician accidentally shut down one of the dam's generators, and the effects were felt by a quarter of a million people in six Western states.
Aluminum manufacturers from Spokane to Vancouver, Wash., had to shut down their potlines. Electricity was cut for 130,000 customers from Boise to Twin Falls, Idaho.
Sixteen skiers were trapped in ski lifts at the Bogus Basin Resort in Idaho, while 500 miles away in Eugene, Ore., 12,000 homes and businesses were temporarily without power.
Accidents are one thing, but the tight-knit dam community here was shocked last November when a mysterious vandal began attacking the world's largest generators in the new powerhouse.
Sabotage is not the only problem that has prevented the Third Powerhouse from attaining its true potential. One unit was damaged by a serious fire in 1977 and subsequently its massive coils had to be rewound. Other units are undergoing extensive repairs and modifications.
Despite its huge electrical output, Grand Coulee's role as the workhouse of the Northwest, soon will change.
Historically, Grand Coulee and other dams along the Columbia and Snake Rivers have provided the basic power (base load in utility jargon) for the region.
The relatively few coal- or oil-fired power plants have been used mainly to supplement this power.
But power planners say these roles will soon be switched as utilities depend on new nuclear and coal-fired plants for the base load and use Grand Coulee for covering excess power demand, or "peaking power."
"It means we'll literally have to turn the river on and off, twice a day," one official said.
This plan raises new problems, though, since these power surges could raise or lower the water level of the Columbia River by 20 feet a day, aggravating an already unstable river bank downstream from Grand Coulee.
At one time it was thought necessary to condemn and remove a number of homes to the towns of Coulee Dam and Elmer City to prevent damage from mud slides.
Now the Water and Power Resource Service has come up with a number of engineering solutions involving drilling wells to pump out groundwater, which it believes will stabilize the banks.