Three years ago, a massive spinning blade flew off a towering turbine at Portland General Electric’s flagship wind farm in Sherman County, bringing scrutiny to the many maintenance problems, safety concerns and production lags that had long plagued one of the state’s largest and oldest wind farms.

Since then, despite increased oversight from regulators, the nearly 20-year-old Biglow Canyon site in northeastern Oregon has continued to report a steady stream of maintenance issues and equipment failures – unlike any other wind farm across the state – prompting PGE to spend increasingly more money on repairs.

PGE, Oregon’s largest electricity provider, is now proposing to construct a new 4,000-acre solar generation and energy storage project within and adjacent to Biglow to increase the energy generated at the site.

But unlike other operators of aging wind farms in the region, PGE doesn’t plan in the near future to change out Biglow’s old turbines with new, highly efficient models – an industry standard known as repowering that can significantly boost energy production and reduce mechanical problems.

State utility regulators want to see PGE’s long-term plans for the site and hope that PGE will figure repowering at the troubled wind farm into its investment calculations.

For now, PGE has promised only to replace or repair some components in the old machines.

Biglow’s turbines are still generating power, so continuing with the old technology keeps prices lower for customers, said PGE spokesperson Drew Hanson.

“The overhaul of plant assets at Biglow is designed to get the maximum value for our customers from existing assets… It is like the calculus you might do when considering ways to keep your car running efficiently for its lifetime versus outright purchasing a brand new vehicle,” he said.

It’s unclear whether that approach, coupled with the solar proposal, will benefit PGE customers who have faced skyrocketing rate increases in recent years. They still need to repay $413 million for Biglow’s wind farm, which cost $1 billion to build. If the solar and storage project moves forward, the utility also would seek to recoup those yet-to-be-determined costs from ratepayers.

PGE’s solar plans come as a growing number of Oregon’s wind farms – the state’s second largest renewable energy source after hydropower, accounting for 15% of Oregon’s electricity generation – are showing signs of age.

Across the U.S. and in Europe, where wind farms have mushroomed over the past few decades, replacing their turbines has become a popular tool to increase power sent to the grid, help achieve clean energy goals, lower maintenance costs and secure government tax credits to keep electricity prices low.

In Oregon, a growing number of legacy wind farms are going that route.

The Oregon Public Utility Commission, which regulates the state’s investor-owned utilities, is anxiously awaiting PGE’s reasoning for not doing the same thing. The explanation likely will come in a long-range planning document PGE is due to submit next year.

“I would hope PGE will say – this is our need and we’ll cover a chunk of that need through wind repowering projects,” said Caroline Moore, the commission’s energy program director. “Because that will help characterize how much new wind, solar and storage they’ll need to buy based on how much they think they can get out of repowering.”

A state utility watchdog group that represents ratepayers also will be watching.

PGE is “going to have to prove that what they’re doing is the most prudent action and to show that the big new solar is a better resource than repowering,” said Bob Jenks, executive director of the Oregon Citizens’ Utility Board, a nonprofit watchdog organization that advocates for utility customers. “We’ll take a hard look at it.”

FIXES DEMANDED

Biglow Canyon stretches over 25,000 acres of still-cultivated cropland just northeast of Wasco. It began operating in 2007, with more turbines added in 2009 and 2010 for a total of 217. They can generate a maximum of 450 megawatts, enough to power about 340,000 homes.

But the flagship hasn’t recovered after the 2022 blade failure, state records show.

PGE has continued to experience multiple issues at Biglow Canyon every year since, according to an incident log obtained by The Oregonian/OregonLive from the state Energy Department. The log is part of the state’s compliance program that requires all large energy facilities to report problems to regulators.

Since 2022, PGE has reported 26 incidents, accounting for more than 40% of all reported incidents at wind facilities statewide. They range from transformer failures and oil spills to pieces of turbines – a nose cone, bolts, hatches and blade shrouds (the flat plates at the end of blades) – falling off into the fields below to a fire caused by an oil leak. In some cases, an incident includes multiple related problems.

“Other aging facilities have not reported significant amounts of maintenance issues,” Energy Department spokesperson Jennifer Kalez told The Oregonian/OregonLive.

Biglow’s challenges continue despite increased scrutiny from regulators over the past three years. The Energy Department meets monthly with PGE to discuss the status of two corrective action plans for Biglow, Kalez said.

The first began in the wake of the detached blade and requires PGE to check the turbines’ bolt torque – the force applied to turn the bolt when it’s tightened – annually instead of every four years, she said.

The second plan, instituted in 2023 for ongoing maintenance issues, focuses on replacing aging turbine components over 11 years – including blade bearings, gearboxes, generators, circuit breakers and transformers, Kalez said.

Thus far, 26 of the 76 turbines from the original phase of Biglow have had parts replaced, Hanson said. And blade bearing bolts have been replaced on all of the 76 towers. Additional upgrades are planned for the remaining turbines, he said.

HIGH COSTS, LAGGING POWER

PGE’s operation and maintenance costs at Biglow have climbed steadily, from $13 million in 2021 and 2022 to $14.3 million in 2023 and $18 million in 2024, according to financial reports filed with the Federal Energy Regulatory Commission. The utility declined to say what projected costs for this year and next were like.

PGE also owns or co-owns three other wind farms — one in Montana, one in Washington and the Wheatridge Renewable Energy Facility in Morrow County — but they came online between 2014 and 2024 and aren’t yet candidates for turbine replacement. They also have much lower maintenance costs, according to the financial reports.

Just as it did before the blade launched into the night, Biglow is still failing to deliver the power production PGE had promised.

Though the site had somewhat recovered the availability of its wind turbines to produce energy – from 77% availability in 2022 when it was temporarily shuttered after the blade launch to 86% in 2023 and 87% in 2024 – it’s still below industry standards. The typical or average availability often exceeds 90% to 95%.

Due to the maintenance work this year, Hanson said, a number of turbines have been offline and the current equipment availability is about 82%, he said. That means payments to rural landowners who lease the land for the turbines have decreased and less clean energy is being produced to meet clean energy goals.

“Our payments are probably down by a third to half. Honestly, almost three and a half years after the blade throw, we expected more,” said landowner Kathryn McCullough, whose husband, Kevin, farms under about half of Biglow Canyon’s turbines, including the one that lost its blade. The couple have declined to sign a solar lease at Biglow. “What we really dislike is how poorly they have managed the wind, so we are not convinced that PGE’s solar would be safe.”

But, PGE officials said, the wind farm continues to produce clean energy so the utility sees no need to do a full replacement yet.

“There is value to all customers in maintaining and upgrading legacy renewable facilities for continued electric service and reliability,” Hanson said. “PGE continues to evaluate the appropriate time for a full repower.”

‘LOW-HANGING FRUIT’

A growing number of wind farms in Oregon – both private and utility-owned – are now considered ‘legacy renewable facilities’ and are nearing the end of their design life. They’re also reaching the end of their initial power purchase agreements, marking a decision point: whether to modernize or decommission the turbines.

Wind energy surged in popularity across the world in the 1990s and early 2000s, with Oregon’s first utility-scale wind farm launching operations in 2001.

Oregon currently has 48 operational wind farms of varying sizes – spinning more than 2,000 turbines – and about a dozen new wind sites in development, according to the U.S. Geological Survey and Oregon Energy Department figures. It’s one of the top states for wind production capacity, though it ranks behind others such as Texas, Iowa, Minnesota or California, which have double or triple Oregon’s wind farm numbers.

Most of Oregon’s wind generation sites are in Wasco, Sherman, Gilliam, Morrow and Umatilla counties along Oregon’s northern border near the Columbia River and in eastern Oregon’s Blue Mountains. They generate nearly 4,000 megawatts of energy, enough to power 3 million homes – 10 times as many as Portland has.

In Oregon, as elsewhere around the U.S. and in Europe, governments and wind farm operators are betting big on turbine replacements, adding longer blades and new gearboxes and modifying or constructing new foundations to support the new turbines.

Though the overhauls can be hampered by how much capacity exists on the transmission system and by the condition of the existing turbine foundations, industry experts say they can increase power production by up to 50% when done well.

And because the oldest wind farms were built at the best wind sites, it makes sense to use the most efficient technology at those farms, they say.

“Repowering is low-hanging fruit,” said Nicole Hughes, executive director of Renewable Northwest, a nonprofit that advocates for building more clean energy projects to meet climate goals in Oregon, Washington, Montana and Idaho.

“These are massive investments in the roads, collector lines, substations and operations and maintenance buildings,” she said, “and people should try and take advantage of those investments.”

Five wind farms – NextEra Energy Resources-owned Stateline Wind Project in Umatilla County (operating since 2001), Brookfield Renewable-owned Shepherds Flats North, South and Central in Gilliam County (operating since 2012) and Avangrid Power-owned Leaning Juniper IIA also in Gilliam County (operating since 2006) – all have all been approved for the turbine upgrades in recent years by the state’s Energy Facility Siting Council, which oversees the development of large energy projects.

Leaning Juniper IIB, also owned by Avangrid in Gilliam County, has requested to repower. It began operating in 2011. Some smaller wind projects approved at the county level in Oregon are also doing the same.

PacifiCorp, another investor-owned utility that serves Oregon residents, has overhauled nearly all of its existing wind farms in Oregon, Washington and Wyoming – 13 projects it already owned and two sites that it acquired and then repowered. The average age of the wind projects at the time of the overhauls was 13 years.

PacifiCorp said its analysts calculated savings of hundreds of millions of dollars for customers. The utility has raised its rates by more than 50% since 2021 – but those increases would have been higher if not for the wind farm overhauls, which reduced the amount of money the utility had to recoup from customers, said PacifiCorp spokesperson Omar Granados.

In general, said Granados, the savings came via reduced maintenance costs and turbine downtime, increased energy output and additional production tax credits.

COMPLEMENTARY SOURCE

PGE has chosen a different path for Biglow Canyon, at least for now.

The proposed solar and storage facility, to be designed by private developer BrightNight for PGE, would take land out of agricultural production – including high-value farmland – and could produce up to 385 megawatts of power, nearly doubling the peak generating capacity at the Biglow site.

PGE currently co-owns only one other large-scale solar and storage project, a part of the Wheatridge wind site in Morrow County. But seeking another project isn’t a surprise. Massive solar projects have grown exponentially in recent years as the technology’s costs have declined and demand for cooling during summer heat waves has swelled.

The utility said it expects the solar and storage project at Biglow to be eligible for tax credits under President Donald Trump’s “One Big Beautiful Bill” — though that legislation still needs to be approved by the Senate.

PGE said the proposed solar and storage project isn’t meant to replace Biglow’s wind generation and won’t restrict the existing wind’s access to transmission. Instead, it’s a complementary source of power that can capture and dispatch solar energy when Biglow isn’t generating wind, Hanson said.

The solar project must first get approval of the state’s energy siting council and go through competitive bidding, a long-range planning process and cost-benefit analysis under the Oregon Public Utility Commission.

Given the amount of clean energy PGE needs to amass to reach the state climate mandate – 100% clean electricity by 2040 – the commission’s Moore said, it’s likely the commission would support both solar and storage at Biglow Canyon, as well as a full repowering.

The state Energy Department said it will issue a preliminary order in six to nine months outlining the findings and recommendations regarding Biglow’s solar and storage project. A hearing and public comment period will be held once the agency issues the draft order.

— Gosia Wozniacka covers environmental justice, climate change, the clean energy transition and other environmental issues. Reach her at gwozniacka@oregonian.com or 971-421-3154.