July 22, 2005

While the Pacific Northwest currently enjoys an electricity surplus big enough to power a city the size of Seattle, hot weather this summer could create shortages for certain hours that force wholesale power prices to high levels, according to the Northwest Power and Conservation Council.

If the Northwest has an electricity surplus of 1,200 megawatts or more, how can it also have an electricity shortage? There are four reasons, according to an analysis by the Council's Power Division staff:

1. First, the surplus primarily is at power plants owned by independent companies, as opposed to electric utilities. Whether or not the plants are running affects the amount of the surplus, as does the amount of power that the independent power producers may be exporting out of the region.. Recently, many of the independent plants were idle because wholesale power prices were too low for the plants to operate profitably.
2. Second, the surplus is calculated over an entire year. It can disappear during periods of high demand, as with extremely hot or cold weather.
3. Third, congestion on the high-voltage transmission network can create isolated shortages and boost prices locally because less-expensive power cannot be imported from long distances.
4. Fourth, water spills this summer at five of the federal dams on the lower Snake and Columbia rivers, ordered by U.S. District Court Judge James Redden last month to protect migrating salmon, effectively eliminate additional generating capacity at those dams. The U.S. Army Corps of Engineers, which operates the dams, and the Bonneville Power Administration, which sells the power, responded by changing the operations of other dams and importing power from the Southwest during periods of high demand, such as last Monday when high temperatures pushed up demand for power during the afternoon.

According to the Council, these factors combine to raise the likelihood of power shortages this summer in the Northwest to 4 percent (from zero before the court order). That figure, however, is within the accepted standard of 5 percent in the Council's recently adopted Fifth Northwest Power Plan.

The Council is an agency of the states of Idaho, Montana, Oregon and Washington and is directed by the Northwest Power Act of 1980 to prepare a program to protect, mitigate and enhance fish and wildlife of the Columbia River Basin affected by hydropower dams while also assuring the region an adequate, efficient, economical and reliable power supply.