Related links: Power Supply Outlook

September 15, 2005

The Pacific Northwest appears to have a surplus of electricity for the coming fall and winter, according to an analysis (480k PDF) by the Council.

"This is the sixth consecutive year of below-average Columbia River runoff, but because new power plants have been built in recent years, here in the Northwest and in California, the supply of power is well above our forecast of demand for power," said Council Chair Melinda Eden, an Oregon member of the Council.

According to the analysis by the Council's power planning staff, the firm power supply totals approximately 23,000 average megawatts. Hydropower accounts for the largest share of the supply, about 51 percent. Electricity from natural gas-fired plants is the second-largest component of the power supply, 21 percent, followed by power from coal-fired plants, 20 percent. According to the analysis, power demand totals about 20,900 average megawatts. That yields a surplus of 2,100 average megawatts. An average megawatt is 1,000 kilowatts delivered every hour continuously for a year; the city of Seattle, for example, consumes about 1,100 average megawatts continuously through the year.

There are three important caveats in the Council's analysis. First, the analysis assumes that 3,000 megawatts of surplus Southwest capacity would be available, if needed for import, over the winter months. Second, the analysis assumes that power will be available from independent power producers, whose plants account for most of the surplus. Third, the analysis uses the medium demand forecast from the Council's Fifth Northwest Power Plan.

Even without help from the Southwest, however, the Northwest still would have an adequate supply, according to the analysis. In either case, the risk of curtailment to service due to an inadequate supply is much less than 5 percent, which is the standard used by the Council in its 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.