Buried line in Columbia River would move power to urban areas

Can slicing a 100-mile trench into the bed of the Columbia River be good for the environment? The answer is a big yes, says a team of energy developers that proposes submerging power cables in the riverbed.

The developers say the cables could deliver “clean’’ energy that will be crucial for getting the most densely developed areas of the Pacific Northwest off fossil fuels.

A proposal by energy developer Sun2o Partners and transmission developer PowerBridge would insert the cables into the Columbia at The Dalles in Oregon. This electrical on-ramp is near the wind farms and solar farms installed along the Columbia Gorge in eastern Oregon and Washington.

The cables also would intersect the monster transmission lines at a Bonneville Power Administration substation, drawing cheaper solar power from the Southwest, steadier wind power from Montana and Wyoming, and reliable backup power from British Columbia’s supersized hydropower reservoirs.

But even climate-conscious developers can’t make plans involving a natural resource like the Columbia River without causing uneasiness among those concerned with ecosystems and communities. Along the Columbia, those affected would include tribal nations and unique cultural interests.

Sun2o and PowerBridge propose to bring their cables ashore in Portland, helping to electrify industries, buildings and vehicles while reducing the use of coal- and gas-fired power plants. Hence the project’s name: Cascade Renewable Transmission.

“The only places you can site solar and wind at scale are, for the most part, east of the Cascades. But the demand, the need for the electricity, is in Portland and Seattle, on the west side,’’ said Corey Kupersmith, the New York-based renewable energy developer who cofounded Sun2o and dreamed up the cable scheme. And power lines that link east and west are filling up fast, he said.

Anticipating environmental concerns, the developers assert they will do little harm to the Columbia, employing high-pressure pumps that make underwater cable installation quick and not so dirty. Water jets would shoot down from a “hydroplow’’ towed along the riverbed, stirring open an 18-inch-wide trench in the sediment.

Environmental impacts, they argue, would likely be short-term and outweighed by environmental gains: reductions in pollution from natural gas, petroleum fuels and coal. That includes emissions of carbon dioxide and methane, two greenhouse gases that are supercharging the region’s wildfires and heat waves and disrupting even the Columbia’s temperature and timing.

To Elaine Harvey, however, the Cascade Renewable Transmission pitch sounds like one more industrial enterprise in a stream of projects that have harmed her people. Such ventures decimated the Columbia River’s fisheries and fenced off and degraded the shrub-steppe grasslands that the Yakama and other tribes and bands ceded in an 1855 treaty with the United States.

A member of the Yakama’s Kah-milt-pa, or Rock Creek, Band, Harvey lives with the legacy of dams, aluminum production, wind farms, expanding solar plants and other development. Each has infringed on her people’s right to pursue traditional practices.

As Harvey and Kah-milt-pa Chief Bronsco Jim Jr. wrote earlier this year in the newsletter of Columbia Riverkeeper: “Ours is a living culture, and we are being cheated by progress. An unrelenting cultural extinction in the name of energy development.’’

However, power-system experts say the grid that sufficed in the fossil-fuel era must increase capacity if renewable electricity is to become the lifeblood of economies.

Wind blows and sunlight shines most reliably in places that are sparsely populated — areas with weak power lines. Stronger grids would enable more power to travel between regions, so those areas can help each other out.

Moving power west over the Cascades means getting access to the Bonneville Power Administration’s regional network, the U.S. Northwest’s transmission backbone. That network is maxing out as a wave of renewable power projects plug in.

And that was before Oregon passed one of North America’s most aggressive grid decarbonization plans. The bill, which Gov. Kate Brown is expected to sign this month, requires Oregon’s investor-owned utilities to deliver 80% carbon-free power by 2030, compared to less than 50% today. It mandates 100% carbon-free electricity by 2040 — five years ahead of deadlines set by Washington state and California.

Hitting a transmission barrier inspired Kupersmith to propose the underwater cables. He knew putting them in the riverbed was an option, because PowerBridge had installed two transmission lines in the Hudson River to ease power bottlenecks in New York City. And he saw a submerged cable as an end-run around opposition to overhead lines that has ended previous grid expansion efforts in the area and frequently ties up projects across the continent.

Kupersmith’s partner at PowerBridge, Chris Hocker, calls overhead lines “hideously problematic,’’ noting that they can take a decade or more to build. In contrast, he and Kupersmith anticipate their Columbia cables would begin pumping electricity in just five years — lightning speed for new transmission.

Of course, that depends on government and community approval. And the partners recently began conversations with the four tribes that have treaty rights in the region, including the Yakama Nation and the Cowlitz Indian Tribe.

The Yakima Nation’s Harvey wants to know where development will stop. “What is this going to lead to? Is this going to lead to wind (turbines) down the middle of the river? What’s down the line?’’

This report is part of Getting to Zero, InvestigateWest’s yearlong reporting initiative on reducing carbon in the Cascadia region. InvestigateWest’s work is supported in part by the Fund for Investigative Journalism.


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