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 Cascadia 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 the Bonneville Power Administration’s Big Eddy 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,” says 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 says.
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 Cascadia’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.”
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, in contrast, enable more power to travel between regions, so those areas can help each other out — precisely what Texas couldn’t do when a deep freeze brought the state to its knees in February and when heat strained its grid last month.
To explore the role of power transmission and the tradeoffs involved in grid expansion, InvestigateWest spoke with Kupersmith, Harvey and Lauren Goldberg, the legal and program director for Columbia Riverkeeper.
Corey Kupersmith: Renewable energy developer
A passion for diving exposed Corey Kupersmith to coral bleaching resulting from water pollution and global warming. An engineer by training and a banker by trade, Kupersmith cofounded New York City–based Sun2o five years ago as a business venture that honors his environmental values
Pursuing solar energy projects in sun-soaked eastern Oregon and Washington inspired him to propose the Cascade link project. Sun2o found plenty of landowners and rural communities eager to host solar panels. But it struggled to secure affordable space on power lines so it could send that energy to the utilities in greatest need of renewable energy.
Moving power west over the Cascades means getting access to the Bonneville Power Administration’s (BPA) regional network, the U.S. Northwest’s transmission backbone. That network is maxing out as a wave of renewable power projects plug in. “BPA has like 28 gigawatts of solar, wind and storage requests,” says Kupersmith. “That’s going to be pushing systems to their limits.”
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.
Bonneville itself is in a tough spot. The federal entity is being financially stretched by rising costs to maintain aging dams and improve impacted salmon fisheries and decreasing revenues as customers defect to cheaper suppliers.
Hitting a transmission barrier inspired Kupersmith to propose the Cascade 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 scuppered previous grid expansion efforts in Cascadia 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. Kupersmith says they had hoped to meet earlier but were delayed by the pandemic and a desire to conduct consultations in person.
Elaine Harvey: Kah-milt-pa activist
For Elaine Harvey, a power line in the Columbia would add to a pile of damaging energy developments over the decades. One of the most devastating was the 1957 completion of The Dalles Dam — one of 14 major dams on the Columbia’s main stem – and decimation of the world’s largest fishery.
The Dalles Dam energized the associated Big Eddy substation, where Kupersmith and his partners hope to plug into BPA’s regional grid, and which has its own painful associations for local tribes.
The Dalles Dam’s 200-foot-high barrier submerged the storied Celilo Falls, where daring dip netters once caught leaping salmon and steelhead. The dam also submerged a complex of villages nearby, which had been a gathering point for traders from tribes across the Northwest. Prior to the dam, it was North America’s oldest site of continuous human habitation.
Those historic insults and other losses remain fresh more than half a century later, as Indigenous communities grapple with a settler culture that often seems incapable of hearing their concerns.
Harvey sees that inability manifested in another proposed grid reinforcement project that she’s fighting, just upstream from The Dalles. The Goldendale Energy Storage Project would build a pair of 60-acre reservoirs, one alongside the river and one on a bluff above. By moving Columbia River water between the reservoirs, the project would store and discharge energy like a giant battery.
The project faces vocal opposition from the Yakama Nation, to whom the site is profoundly sacred. Yakama stories recall the bluffs as a haven during great floods in millennia past, and Harvey says her band still forages there for culturally important “first foods,” such as desert parsley.
They already have lost much access to foraging sites because wind farms have fenced off large areas. Only one landowner hosting a wind farm allows Harvey’s people to enter and gather traditional plants, she says.
Harvey asks whether the onslaught of development in the Columbia Gorge is necessary. She questions whom the projects are intended to benefit, noting with suspicion the express line running between BPA’s Big Eddy hub and Los Angeles.
The express line and others were built in the 1960s to help power California. In the future, excess solar power could flow north when the sun is up. But today, the lines’ primary use remains the shipment of hydropower from the Columbia River dams and British Columbia south to California.
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?”
Climate change also worries Harvey. A biologist by training, she knows warmer water represents a growing threat to the Columbia’s struggling fisheries.
Harvey thinks other solutions need to be considered. Gas-fired power plants can be equipped to capture the CO2 they produce. Smarter logging practices and coastal protections can boost the ability of inland forests and kelp forests to capture atmospheric CO2. Rooftop solar panels can generate power where it’s needed most.
Bottom line, says Harvey: “We already gave up enough.”
Lauren Goldberg: River defender and lawyer
For Lauren Goldberg, projects like the Cascade cables present an acute challenge. Goldberg, a 15-year veteran at Columbia Riverkeeper, sees fossil fuels and climate change as existential threats to the river and the communities that rely on it. This is a reason Riverkeeper has been a mainstay in the “Thin Green Line” movement that has blocked many efforts to push more coal, oil and liquefied natural gas down the rail lines transiting the Gorge.
And it’s why it advocates for clean energy production. “The Columbia River is already being impacted by the climate crisis, and the projections are dire,” says Goldberg.
Goldberg says a lot of green energy development has happened in the Columbia Basin, and she expects that will continue. But that does not mean every project that calls itself renewable and green gets a pass?
And even if submerged power cables are deemed important for energy transition, for Goldberg their carbon-cutting potential must outweigh their direct environmental impacts.
“Whether it’s renewable energy or fossil energy, we need to understand how a project is going to impact people that rely on the Columbia for salmon and for clean water,” says Goldberg.
Goldberg stresses that burying 100-mile-long power cables in the riverbed is a concept that Riverkeeper has yet to grapple with. Based on experience and preliminary research, Goldberg identifies several issues. One is the impact from stirring up sediment. She says that while the Columbia is “incredibly beautiful,” it’s by no means “pristine.”
Another potential impact mentioned by Goldberg could come from the electromagnetic fields generated by power cables. Research commissioned by the federal Bureau of Ocean Energy Management looked at magnetic fields emanating from similar transmission cables laid across San Francisco Bay. Those cables helped reduce San Francisco’s dependence on gas-fired power plants.
The study found that the cables had some effects on migratory fish like salmon, which navigate partly by sensing Earth’s magnetic fields. For example, the cables increased the chance that salmon smolts would take a wrong turn that lengthened their journey to the ocean. But it detected no evidence that fish were harmed. Fish appeared to be just as successful at migrating through the bay after the cables were turned on.
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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.
