Project Overview
The Cascade Project is an underwater and underground transmission line capable of transferring approximately 1,100 MW of large-scale wind, solar, and other renewables to help meet renewable energy public policy requirements in Oregon and Washington. Cascade will have no visual impact on or disturbance to the natural habitat or populated areas. Underwater burial in the river will use well-proven benign methods that have no permanent impacts on river habitat and important species.
The Project starts in The Dalles, Oregon and runs approximately 80 miles beneath the Columbia River to the Portland area. At the Bonneville Dam, the underwater cable will safely exit the river above the dam and will be buried underground for approximately 7.5 miles before re-entering the river and continuing west.
A converter station, approximately five acres in size, will be built near each interconnection point at existing electrical infrastructure at The Dalles and Portland. The purpose of the converter stations, which are similar to standard electric substations, is to convert alternating current (“AC”) power to direct current (“DC”) power, which facilitates safe, efficient underwater transfer over a long distance, before converting it back to AC power to match the existing electrical grid.
Major electrical infrastructure outside of The Dalles is shown to the right. In the foreground is the Celilo Converter Station, the northern terminal of the Pacific HVDC Intertie. BPA’s Big Eddy Substation, the proposed eastern interconnection point of the Cascade Project, is in the middle of the photo. Lastly, part of The Dalles dam is visible in the Columbia River in the background.
The Dalles Dam on the Columbia River and BPA’s Big Eddy Substation The Dalles, Oregon
Meeting an Urgent Need
The Pacific Northwest – Oregon and Washington in particular – is facing an imminent shortage of generation capacity needed to serve customers and meet public policy requirements. Recent studies estimate the capacity shortage to be approximately 3,000 megawatts (MW) by 2025, growing to over 10,000 MW by 2030 – before considering many public policy needs. Both Washington and Oregon have enacted legislation to phase out fossil fueled energy sources and replace them with carbon-free sources. Yet, almost all large-scale wind, solar, and other renewable resources that can be developed in time to meet these demands are located east of the Cascades. The Cascade Project will deliver this clean, affordable, renewable energy across the Cascades to customers in need.
The Project will continue to work closely with the Western Electricity Coordinating Council (WECC), NorthernGrid, the regional transmission planning organization, BPA, and local electric utilities to assure that the Project conforms to coordination and reliability requirements for the regional power grid and provides maximum benefits to the electrical system.
