The Bonneville Power Administration (BPA), Puget Sound Energy (PSE) and Seattle City Light (SCL) have signed a memorandum of agreement (MOA) aimed at improving the reliability of the regional electric grid and reducing the probability of region-wide customer power outages in the future.
The MOA includes six proposed transmission improvement projects that aim to significantly improve electric reliability for electric utility customers in the Puget Sound area. In all, the projects are estimated to cost approximately $140 million and involve either transmission-line upgrades or equipment additions at existing facilities.
"The transmission system serving the Puget Sound region is at capacity and needs to be upgraded," says Brian Silverstein, senior vice president at BPA Transmission Services. “Several decades have passed since we and the area utilities have jointly invested in large, regional bulk-power transmission projects. Now is the time to consider these projects to avoid load curtailments and potential region-wide power outages in the future.”
In developing the projects covered by the MOA, the BPA, PSE, SCL and Snohomish County Public Utility District looked to the technical work of the ColumbiaGrid’s Puget Sound Area Study Team, which has studied and analyzed the regional bulk electric transmission system for several years to help develop the “one-utility” planning approach.
When large amounts of energy are being delivered to the Puget Sound area through the Northern Intertie to Canada, oftentimes, transmission lines become congested. To relieve this congestion and avoid unplanned power interruptions to customers, BPA currently limits or curtails the amount of energy Puget Sound-area utilities and Canadian utilities can deliver across certain transmission lines. This curtailment process has been in place since fall 2007.
Energy-demand projections for the Puget Sound area and the potential for additional energy delivery from the Northwest to Canada have transmission system planners projecting increased curtailments by the end of this decade.
When the curtailments are instituted, utilities have to make changes to the generating resources providing power to the area, BPA says, which can be costly to Puget Sound-area customers and the environment. The new projects will significantly expand system capacity and minimize the need for curtailments - such as last spring’s 350 MW wind energy curtailment - and potential rolling blackouts, BPA adds.