Drive for geothermal heats up on U.S. campuses

BC Utilities Commission Site C Dam Questions press BC Hydro on geotechnical risks, stability issues, cost overruns, oversight gaps, seeking transparency for ratepayers and clarity on contracts, mitigation, and the powerhouse and spillway foundations.

Key Points

Inquiry seeking explanations from BC Hydro on geotechnical risks, costs, timelines and oversight for Site C.

✅ Timeline of studies, monitoring, and mitigation actions

✅ Rationale for contracts, costs, and right bank construction

✅ Implications for ratepayers, oversight, and project stability

The watchdog B.C. Utilities Commission has sent BC Hydro 70 questions about the troubled Site C dam, asking when geotechnical risks were first identified and when the project’s assurance board was first made aware of potential issues related to the dam’s stability. 

“I think they’ve come to the conclusion — but they don’t say it — that there’s been a cover-up by BC Hydro and by the government of British Columbia,” former BC Hydro CEO Marc Eliesen told The Narwhal. 

On Oct. 21, The Narwhal reported that two top B.C. civil servants, including the senior bureaucrat who prepares Site C dam documents for cabinet, knew in May 2019 that the project faced serious geotechnical problems due to its “weak foundation” and the stability of the dam was “a significant risk.” 

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“They [the civil servants] would have reported to their ministers and to the government in general,” said Eliesen, who is among 18 prominent Canadians calling for a halt to Site C work until an independent team of experts can determine if the geotechnical problems can be resolved and at what cost.  

“It’s disingenuous for Premier [John] Horgan to try to suggest, ‘Well, I just found out about it recently.’ If that’s the case, he should fire the public servants who are representing the province.” 

The public only found out about significant issues with the Site C dam at the end of July, when BC Hydro released overdue reports saying the project faces unknown cost overruns, schedule delays and, even as it achieved a transmission line milestone earlier, such profound geotechnical troubles that its overall health is classified as ‘red,’ meaning it is in serious trouble. 

“The geotechnical challenges have been there all these years.”

The Site C dam is the largest publicly funded infrastructure project in B.C.’s history. If completed, it will flood 128 kilometres of the Peace River and its tributaries, forcing families from their homes and destroying Indigenous gravesites, hundreds of protected archeological sites, some of Canada’s best farmland and habitat for more than 100 species vulnerable to extinction.

Eliesen said geotechnical risks were a key reason BC Hydro’s board of directors rejected the project in the early 1990s, when he was at the helm of BC Hydro.

“The geotechnical challenges have been there all these years,” said Eliesen, who is also the former Chair and CEO of Ontario Hydro, where Ontario First Nations have urged intervention on a critical electricity line, the former Chair of Manitoba Hydro and the former Chair and CEO of the Manitoba Energy Authority.

Elsewhere, a Manitoba Hydro line to Minnesota has faced potential delays, highlighting broader grid planning challenges.

The B.C. Utilities Commission is an independent watchdog that makes sure ratepayers — including BC Hydro customers — receive safe and reliable energy services, as utilities adapt to climate change risks, “at fair rates.”

The commission’s questions to BC Hydro include 14 about the “foundational enhancements” BC Hydro now says are necessary to shore up the Site C dam, powerhouse and spillways. 

The commission is asking BC Hydro to provide a timeline and overview of all geotechnical engineering studies and monitoring activities for the powerhouse, spillway and dam core areas, and to explain what specific risk management and mitigation practices were put into effect once risks were identified.

The commission also wants to know why construction activities continued on the right bank of the Peace River, where the powerhouse would be located, “after geotechnical risks materialized.” 

It’s asking if geotechnical risks played a role in BC Hydro’s decision in March “to suspend or not resume work” on any components of the generating station and spillways.

The commission also wants BC Hydro to provide an itemized breakdown of a $690 million increase in the main civil works contract — held by Spain’s Acciona S.A. and the South Korean multinational conglomerate Samsung C&T Corp. — and to explain the rationale for awarding a no-bid contract to an unnamed First Nation and if other parties were made aware of that contract. 

Peace River Jewels of the Peace Site C The Narwhal
Islands in the Peace River, known as the ‘jewels of the Peace’ will be destroyed for fill for the Site C dam or will be submerged underwater by the dam’s reservoir, a loss that opponents are sharing with northerners in community discussions. Photo: Byron Dueck

B.C. Utilities Commission chair and CEO David Morton said it’s not the first time the commission has requested additional information after receiving BC Hydro’s quarterly progress reports on the Site C dam. 

“Our staff reads them to make sure they understand them and if there’s anything in then that’s not clear we go then we do go through this, we call it the IR — information request — process,” Morton said in an interview.

“There are things reported in here that we felt required a little more clarity, and we needed a little more understanding of them, so that’s why we asked the questions.”

The questions were sent to BC Hydro on Oct. 23, the day before the provincial election, but Morton said the commission is extraordinarily busy this year and that’s just a coincidence. 

“Our resources are fairly strained. It would have been nice if it could have been done faster, it would be nice if everything could be done faster.” 

“These questions are not politically motivated,” Morton said. “They’re not political questions. There’s no reason not to issue them when they’re ready.”

The commission has asked BC Hydro to respond by Nov. 19.

Read more: Top B.C. government officials knew Site C dam was in serious trouble over a year ago: FOI docs

Morton said the independent commission’s jurisdiction is limited because the B.C. government removed it from oversight of the project. 

The commission, which would normally determine if a large dam like the Site C project is in the public’s financial interest, first examined BC Hydro’s proposal to build the dam in the early 1980s.

After almost two years of hearings, including testimony under oath, the commission concluded B.C. did not need the electricity. It found the Site C dam would have negative social and environmental impacts and said geothermal power should be investigated to meet future energy needs. 

The project was revived in 2010 by the BC Liberal government, which touted energy from the Site C dam as a potential source of electricity for California and a way to supply B.C.’s future LNG industry with cheap power.

Not willing to countenance another rejection from the utilities commission, the government changed the law, stripping the commission of oversight for the project. The NDP government, which came to power in 2017, chose not to restore that oversight.

“The approval of the project was exempt from our oversight,” Morton said. “We can’t come along and say ‘there’s something we don’t like about what you’re doing, we’re going to stop construction.’ We’re not in that position and that’s not the focus of these questions.” 

But the commission still retains oversight for the cost of construction once the project is complete, Morton said. 

“The cost of construction has to be recovered in [hydro] rates. That means BC Hydro will need our approval to recover their construction cost in rates, and those are not insignificant amounts, more than $10.7 billion, in all likelihood.” 

In order to recover the cost from ratepayers, the commission needs to be satisfied BC Hydro didn’t spend more money than necessary on the project, Morton said. 

“As you can imagine, that’s not a straight forward review to do after the fact, after a 10-year construction project or whatever it ends up being … so we’re using these quarterly reports as an opportunity to try to stay on top of it and to flag any areas where we think there may be areas we need to look into in the future.”

The price tag for the Site C dam was $10.7 billion before BC Hydro’s announcement at the end of July — a leap from $6.6 billion when the project was first announced in 2010 and $8.8 billion when construction began in 2015. 

Eliesen said the utilities commission should have been asking tough questions about the Site C dam far earlier. 

“They’ve been remiss in their due diligence activities … They should have been quicker in raising questions with BC Hydro, rather than allowing BC Hydro to be exceptionally late in submitting their reports.” 

BC Hydro is late in filing another Site C quarterly report, covering the period from April 1 to June 30. 

The quarterly reports provide the B.C. public with rare glimpses of a project that international hydro expert Harvey Elwin described as being more secretive than any hydro project he has encountered in five decades working on large dams around the world, including in China.

Read more: Site C dam secrecy ‘extraordinary’, international hydro construction expert tells court proceeding

Morton said the commission could have ordered regular reporting for the Site C project if it had its previous oversight capability.

“Then we would have had the ability to follow up and ultimately order any delinquent reports to be filed. In this circumstance, they are being filed voluntarily. They can file it as late as they choose. We don’t have any jurisdiction.” 

In addition to the six dozen questions, the commission has also filed confidential questions with BC Hydro. Morton said confidential information could include things such as competitive bid information. “BC Hydro itself may be under a confidentiality agreement not to disclose it.” 

With oversight, the commission would also have been able to drill down into specific project elements,  Morton said. 

“We would have wanted to ensure that the construction followed what was approved. BC Hydro wouldn’t have the ability to make significant changes to the design and nature of the project as they went along.”

BC Hydro has been criticized for changing the design of the Site C dam to an L-shape, which Eliesen said “has never been done anywhere in the world for an earthen dam.” 

Morton said an empowered commission could have opted to hold a public hearing about the design change and engage its own technical consultants, as it did in 2017 when the new NDP government asked it to conduct a fast-tracked review of the project’s economics. 

Construction Site C Dam
A recent report by a U.S. energy economist found cancelling the Site C dam project would save BC Hydro customers an initial $116 million a year, with increasing savings growing over time. Photo: Garth Lenz / The Narwhal

The commission’s final report found the dam could cost more than $12 billion, that BC Hydro had a historical pattern of overestimating energy demand and that the same amount of energy could be produced by a suite of renewables, including wind and proposed pumped storage such as the Meaford project, for $8.8 billion or less. 

The NDP government, under pressure from construction trade unions, opted to continue the project, refusing to disclose key financial information related to its decision. 

When the geotechnical problems were revealed in July, the government announced the appointment of former deputy finance minister Peter Milburn as a special Site C project advisor who will work with BC Hydro and the Site C project assurance board to examine the project and provide the government with independent advice.

Eliesen said BC Hydro and the B.C. government should never have allowed the recent diversion of the Peace River to take place given the tremendous geotechnical challenges the project faces and its unknown cost and schedule for completion. 

“It’s a disgrace and scandalous,” he said. “You can halt the river diversion, but you’ve got another four or five years left in construction of the dam. What are you going to do about all the cement you’ve poured if you’ve got stability problems?”

He said it’s counter-productive to continue with advice “from the same people who have been wrong, wrong, wrong,” without calling in independent global experts to examine the geotechnical problems. 

“If you stop construction, whether it takes three or six months, that’s the time that’s required in order to give yourself a comfort level. But continuing to do what you’ve been doing is not the right course. You should have to sit back.”

Eliesen said it reminded him of the Pete Seeger song Waist Deep in the Big Muddy, which tells the story of a captain ordering his troops to keep slogging through a river because they will soon be on dry ground. After the captain drowns, the troops turn around.

“It’s a reflection of the fact that if you don’t look at what’s new, you just keep on doing what you’ve been doing in the past and that, unfortunately, is what’s happening here in this province with this project.”

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Los Angeles Power Station Fire prompts LADWP to shut a Northridge/Reseda substation, causing a San Fernando Valley outage amid a heatwave; high-voltage equipment and mineral oil burned as 94,000 customers lost power, elevator rescues reported.

Key Points

An LADWP substation fire in Northridge/Reseda caused a major outage; 94,000 customers affected as crews restore power.

✅ Fire started around 6:52 p.m.; fully extinguished by 9 p.m.

✅ High-voltage gear and mineral oil burned; no injuries reported.

✅ Outages hit Porter Ranch, Reseda, West Hills, Granada Hills.

About 94,000 customers were without electricity Saturday night after the Los Angeles Department of Water and Power shut down a power station in the northeast San Fernando Valley that caught fire, the agency said.

The fire at the station in the Northridge/Reseda area of Los Angeles started about 6:52 p.m. and involved equipment that carries high-voltage electricity and distributes it at lower voltages to customers in the surrounding area, the department said, even as other utilities sometimes deploy wildfire safety shut-offs to reduce risk during dangerous conditions.

The department shut off power to the station as a precautionary move, and it is restoring power now that the fire has been put out, similar to restoration after intentional shut-offs in other parts of California. Initially, 140,000 customers were without power. That number had been cut to 94,000 by 11 p.m.

The power outage comes as much of California baked in heat that broke records, and rolling blackout warnings were issued as the grid strained. A record that stood 131 years in Los Angeles was snapped when the temperature spiked at 98 degrees downtown.

People reported losing power in Porter Ranch, Winnetka, West Hills, Canoga Park, Woodland Hills, Granada Hills, North Hills, Reseda and Chatsworth, KABC TV reported, highlighting electricity inequality across communities.

Shortly after the blaze broke out, firefighters found a huge container of mineral oil that is used to cool electrical equipment on fire, Los Angeles Fire Department spokesman Brian Humphrey told the Los Angeles Times. The incident underscores infrastructure risks that in some regions have required a complete grid rebuild after severe storms.

Firefighters had the blaze under control by 8:30 p.m. and were able to put it out by 9 p.m., Humphrey said. "These were fierce flames, with smoke towering more than 300 feet into the sky," he told the newspaper.

No one was injured.

Firefighters rescued people who were stranded in elevators, Humphrey said.

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Wind Turbine Cancer Claim debunked: Iowa Republican senators back wind energy as fact-checks and DOE research find no link between turbine noise and cancer, limited effects on property values, and manageable wildlife impacts.

Key Points

Claims that turbine noise causes cancer, dismissed by studies and officials as unsupported by evidence.

✅ Grassley and Ernst call the claim idiotic and ridiculous

✅ DOE studies find no cancer link; property impacts limited

✅ Wildlife impacts mitigated; climate change poses larger risks

President Donald Trump may not be a fan of wind turbines, as shown by his pledge to scrap offshore wind projects earlier, suggesting that the noise they produce may cause cancer, but Iowa's Republican senators are big fans of wind energy.

Sen. Chuck Grassley called Trump's cancer claim "idiotic." On Thursday, Sen. Joni Ernst called the statement "ridiculous."

"I would say it's ridiculous. It's ridiculous," Ernst said, according to WHO-TV.

She likened the claim that wind turbine noise causes cancer to the idea that church bells do the same.

"I have church bells that ring all the time across from my office here in D.C. and I know that noise doesn't give me cancer, otherwise I'd have 'church bell cancer,'" Ernst said, adding that she is "thrilled" to have wind energy generation in Iowa, which aligns with a quarter-million wind jobs forecast nationwide. "I don't know what the president is drawing from."

Trump has a history of degrading wind energy and wind turbines that dates back long before his Tuesday claim that turbines harm property values and cause cancer, and often overlooks Texas grid constraints that can force turbines offline at times.

Not only are wind farms disgusting looking, but even worse they are bad for people's health.

"Not only are wind farms disgusting looking, but even worse, they are bad for people's health," Trump tweeted back in 2012.

Repeated fact-checks have found no scientific evidence to support the claim that wind turbines and the noise they make can cause cancer. The White House has reportedly provided no evidence to support Trump's cancer claim when asked this week

"It just seems like every time you turn around there's another thing the president is saying -- wind power causes cancer, I associate myself with the remarks of Chairman Grassley -- it's an 'idiotic' statement," Pelosi said in her weekly news conference on Thursday.

The president made his latest claim about wind turbines in a speech on Tuesday at a Republican spring dinner, as the industry continued recovering from the COVID-19 crisis that hit solar and wind energy.

"If you have a windmill anywhere near your house, congratulations, your house just went down 75 percent in value -- and they say the noise causes cancer," Trump said Tuesday, swinging his arm in a circle and making a cranking sound to imitate the noise of windmill blades. "And of course it's like a graveyard for birds. If you love birds, you never want to walk under a windmill. It’s a sad, sad sight."

Wind turbines are not, in fact, proven to have widespread negative impacts on property values, according to the Department of Energy's Office of Scientific and Technical Information in the largest study done so far in the U.S., even as some warn that a solar ITC extension could be devastating for the wind market, and there is no peer-reviewed data to back up the claim that the noise causes cancer.

I am considered a world-class expert in tourism. When you say, 'Where is the expert and where is the evidence?' I say: I am the evidence.

It's true wildlife is affected by wind turbines -- particularly birds and bats, with research showing whooping cranes avoid turbines when selecting stopover sites. One study estimated between 140,000 and 328,000 birds are killed annually by collisions with turbines across the U.S. The U.S. Energy Information Administration estimated, however, that other human-related impacts also contribute to declines in population.

The wind industry works with biologists to find solutions to the impact of turbines on wildlife, and the Department of Energy awards grants each year to researchers addressing the issue, even as the sector faced pandemic investment risks in 2020. But, overall, scientists warn that climate change itself is a bigger threat to bird populations than wind turbines, according to the National Audobon Society.

Speaker Nancy Pelosi: "It just seems like every time you turn around, there's another thing. The president is saying wind power causes cancer. I associate myself with the remarks of Chairman Grassley; It's an 'idiotic' statement"

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Nation Rise Wind Farm Ruling overturns Ontario cancellation, as Superior Court finds the minister's decision unreasonable; EDP Renewables restarts 100-megawatt project near Cornwall, citing jobs, clean energy, and procedural fairness over bat habitat concerns.

Key Points

Ontario court quashes cancellation, letting EDP Renewables finish 100 MW Nation Rise project and resume clean energy.

✅ Judges call minister's decision unreasonable, unfair

✅ EDP Renewables to restart construction near Cornwall

✅ 100 MW, 29 turbines; costs awarded, appeal considered

Construction of a wind farm in eastern Ontario, as wind power makes gains nationwide, will move ahead after a court quashed a provincial government decision to cancel the project.

In a ruling released Wednesday, a panel of Ontario Superior Court judges said the province's decision to scrap the Nation Rise Wind Farm in December 2019 did not meet the proper requirements.

At the time, Environment Minister Jeff Yurek revoked the approvals of the project near Cornwall, Ont., citing the risk to three bat species.

That decision came despite a ruling from the province's Environmental Review Tribunal that determined the risk the project posed to the bat population was negligible.

The judges said the minister's decision was "unreasonable" and "procedurally unfair."

"The decision does not meet requirements of transparency, justification, and intelligibility, as the Minister has failed to adequately explain his decision," the judges wrote in their decision.

The company behind the project, EDP Renewables, said the 29-turbine wind farm was almost complete when its approval was revoked in December, even as Alberta saw TransAlta scrap a wind farm in a separate development.

The company said Thursday it plans to restart construction on the 100-megawatt wind farm.

"EDPR is eager to recommence construction of the Nation Rise Wind Farm, which will bring much-needed jobs and investment to the community," the company said in a statement. "This delay has resulted in unnecessary expenditures to-date, at a time when governments and businesses should be focused on reducing costs and restarting the economy."

A spokesman for Yurek said the government is disappointed with the outcome of the case but did not comment on a possible appeal.

"At this time, we are reviewing the decision and are carefully considering our next steps," Andrew Buttigieg said in a statement.

NDP climate change critic Peter Tabuns said the court decision is an embarrassment for the minister and the government. He urged the government not to pursue an appeal.

Yurek "was found to have ignored the evidence and the facts," he said. "They didn't just lose, their case collapsed. They had nothing to stand on. Taking this to appeal would be a complete and total waste of money."

Green party Leader Mike Schreiner said the ruling proves the government was acting based on ideology over evidence when it revoked the project's approval.

"As we shift towards a post-COVID recovery, we need the Ford government to give up the irrational crusade against affordable and reliable clean energy," Schreiner said in a statement.

Last year, the NDP revealed the province had spent $231 million to cancel more than 750 renewable energy contracts, a move Ford said he was proud of, shortly after winning the 2018 election.

The Progressive Conservatives have blamed the previous Liberal government, as leadership candidates debate how to fix power, for signing the bad energy deals while the province had an oversupply of electricity.

The Ford government, amid a new stance on wind power, has also said that by cancelling the contracts it would ultimately save ratepayers $790 million -- a figure industry officials have disputed.

At the time of the wind farm cancellation, the government also said it would introduce legislation that would protect consumers from any costs incurred, though a developer warned cancellations could exceed $100M at the time.

It has since acknowledged it will have to pay some companies to cancel the deals and set aside $231 million to reach agreements with those firms, and more recently has moved to reintroduce renewable projects in some cases.

On Wednesday, the judges awarded Nation Rise $126,500 in costs, which the government will have to pay.

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Canadian Electricity Innovation drives a customer-centric, data-driven grid, integrating renewable energy, EVs, storage, and responsive loads to boost reliability, resilience, affordability, and sustainability while aligning regulators, utilities, and policy for decarbonization.

Key Points

A plan to modernize the grid, aligning utilities, regulators, and tech to deliver clean, reliable, affordable power.

✅ Smart grid supports EVs, storage, solar, and responsive loads.

✅ Innovation funding and regulatory alignment cut long-term costs.

✅ Resilience rises against extreme weather and outage risks.

For more than 100 years, Canadian electricity companies had a very simple mandate: provide reliable, safe power to all. Keep the lights on, as some would say. And they did just that.

Today, however, they are expected to also provide a broad range of energy services through a data-driven, customer-centric system operations platform that can manage, among other things, responsive loads, electric vehicles, storage devices and solar generation. All the while meeting environmental and social sustainability — and delivering on affordability.

Not an easy task, especially amid a looming electrical supply crunch that complicates planning.

That’s why this new mandate requires an ironclad commitment to innovation excellence. Not simply replacing “like with like,” or to make incremental progress, but to fundamentally reimagine our electricity system and how Canadians relate to it.

Our innovators in the electricity sector are stepping up to the plate and coming up with ingenious ideas, thanks to an annual investment of some $20 billion.

#google#

But they are presented with a dilemma.

Although Canada enjoys among the cleanest, most reliable electricity in the world, we have seen a sharp spike in its politicization. Electricity rates have become the rage and a top-of-mind issue for many Canadians, as highlighted by the Ontario hydro debate over rate plans. Ontario’s election reflects that passion.

This heightened attention places greater pressure on provincial governments, who regulate prices, and in jurisdictions like the Alberta electricity market questions about competition further influence those decisions. In turn, they delegate down to the actual regulators where, at their public hearings, the overwhelming and almost exclusive objective becomes: Keeping costs down.

Consequently, innovation pilot applications by Canadian electricity companies are routinely rejected by regulators, all in the name of cost constraints.

Clearly, electricity companies must be frugal and keep rates as low as possible.

No one likes paying more for their electricity. Homeowners don’t like it and neither do businesses.

Ironically, our rates are actually among the lowest in the world. But the mission of our political leaders should not be a race to the basement suite of prices. Nor should cheap gimmicks masquerade as serious policy solutions. Not if we are to be responsible to future generations.

We must therefore avoid, at all costs, building on the cheap.

Without constant innovation, reliability will suffer, especially as we battle more extreme weather events. In addition, we will not meet the future climate and clean energy targets such as the Clean Electricity Regulations for 2050 that all governments have set and continuously talk about. It is therefore incumbent upon our governments to spur a dynamic culture of innovation. And they must sync this with their regulators.

This year’s federal budget failed to build on the 2017 investments. One-time public-sector funding mechanisms are not enough. Investments must be sustained for the long haul.

To help promote and celebrate what happens when innovation is empowered by utilities, the Canadian Electricity Association has launched Canada’s first Centre of Excellence on electricity. The centre showcases cutting-edge development in how electricity is produced, delivered and consumed. Moreover, it highlights the economic, social and environmental benefits for Canadians.

One of the innovations celebrated by the centre was developed by Nova Scotia’s own NS Power. The company has been recognized for its groundbreaking Intelligent Feeder Project that generates power through a combination of a wind farm, a substation, and nearly a dozen Tesla batteries, reflecting broader clean grid and battery trends across Canada.

Political leaders must, of course, respond to the emotions and needs of their electors. But they must also lead.

That’s why ongoing long-term investments must be embedded in the policies of federal, provincial and territorial governments, and their respective regulatory systems. And Canada’s private sector cannot just point the finger to governments. They, too, must deliver, by incorporating meaningful innovation strategies into their corporate cultures and vision.

That’s the straightforward innovation challenge, as it is for the debate over rates.

But it also represents a generational opportunity, because if we get innovation right we will build that better, greener future that Canadians aspire to.

Sergio Marchi is president and CEO of the Canadian Electricity Association. He is a former Member of Parliament, cabinet minister, and Canadian Ambassador to the World Trade Organization and United Nations in Geneva.

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US SF6 Emissions Decline as NOAA analysis and EPA mitigation show progress, with atmospheric measurements and Greenhouse Gas Reporting verifying reductions from the electric power grid; sulfur hexafluoride's extreme global warming potential underscores inventory improvements.

Key Points

A documented drop in US sulfur hexafluoride emissions, confirmed by NOAA atmospheric data and EPA reporting reforms.

✅ NOAA towers and aircraft show 2007-2018 decline

✅ EPA reporting and utility mitigation narrowed inventory gaps

✅ Winter leaks and servicing signal further reduction options

A new NOAA analysis shows U.S. emissions of the super-potent greenhouse gas sulfur hexafluoride (SF6) have declined between 2007-2018, likely due to successful mitigation efforts by the Environmental Protection Agency (EPA) and the electric power industry, with attention to SF6 in the power industry across global markets. 

At the same time, significant disparities that existed previously between NOAA’s estimates, which are based on atmospheric measurements, and EPA’s estimates, which are based on a combination of reported emissions and industrial activity, have narrowed following the establishment of the EPA's Greenhouse Gas Reporting Program. The findings, published in the journal Atmospheric Chemistry and Physics, also suggest how additional emissions reductions might be achieved. 

SF6 is most commonly used as an electrical insulator in high-voltage equipment that transmits and distributes electricity, and its emissions have been increasing worldwide as electric power systems expand, even as regions hit milestones like California clean energy surpluses in recent years. Smaller amounts of SF6 are used in semiconductor manufacturing and in magnesium production. 

SF6 traps 25,000 times more heat than carbon dioxide over a 100-year time scale for equal amounts of emissions, and while CO2 emissions flatlined in 2019 globally, that comparison underscores the potency of SF6. That means a relatively small amount of the gas can have a significant impact on climate warming. Because of its extremely large global warming potential and long atmospheric lifetime, SF6 emissions will influence Earth’s climate for thousands of years.

In this study, researchers from NOAA’s Global Monitoring Laboratory, as record greenhouse gas concentrations drive demand for better data, working with colleagues at EPA, CIRES, and the University of Maryland, estimated U.S. SF6 emissions for the first time from atmospheric measurements collected at a network of tall towers and aircraft in NOAA’s Global Greenhouse Gas Reference Network. The researchers provided an estimate of SF6 emissions independent from the EPA’s estimate, which is based on reported SF6 emissions for some industrial facilities and on estimated SF6 emissions for others.

“We observed differences between our atmospheric estimates and the EPA’s activity-based estimates,” said study lead author Lei Hu, a Global Monitoring Laboratory researcher who was a CIRES scientist at the time of the study. “But by closely collaborating with the EPA, we were able to identify processes potentially responsible for a significant portion of this difference, highlighting ways to improve emission inventories and suggesting additional emission mitigation opportunities, such as forthcoming EPA carbon capture rules for power plants, in the future.” 

In the 1990s, the EPA launched voluntary partnerships with the electric power, where power-sector carbon emissions are falling as generation shifts, magnesium, and semiconductor industries to reduce SF6 emissions after the United States recognized that its emissions were significant. In 2011, large SF6 -emitting facilities were required to begin tracking and reporting their emissions under the EPA Greenhouse Gas Reporting Program. 

Hu and her colleagues documented a decline of about 60 percent in U.S. SF6 emissions between 2007-2018, amid global declines in coal-fired power in some years—equivalent to a reduction of between 6 and 20 million metric tons of CO2 emissions during that time period—likely due in part to the voluntary emission reduction partnerships and the EPA reporting requirement. A more modest declining trend has also been reported in the EPA’s national inventories submitted annually under the United Nations Framework Convention on Climate Change. 

Examining the differences between the NOAA and EPA independent estimates, the researchers found that the EPA’s past inventory analyses likely underestimated SF6 emissions from electrical power transmission and distribution facilities, and from a single SF6 production plant in Illinois. According to Hu, the research collaboration has likely improved the accuracy of the EPA inventories. The 2023 draft of the EPA’s U.S. Greenhouse Gas Emissions and Sinks: 1990-2021 used the results of this study to support revisions to its estimates of SF6 emissions from electrical transmission and distribution. 

The collaboration may also lead to improvements in the atmosphere-based estimates, helping NOAA identify how to expand or rework its network to better capture emitting industries or areas with significant emissions, according to Steve Montzka, senior scientist at GML and one of the paper’s authors.

Hu and her colleagues also found a seasonal variation in SF6 emissions from the atmosphere-based analysis, with higher emissions in winter than in summer. Industry representatives identified increased servicing of electrical power equipment in the southern states and leakage from aging brittle sealing materials in the equipment in northern states during winter as likely explanations for the enhanced wintertime emissions—findings that suggest opportunities for further emissions reductions.

“This is a great example of the future of greenhouse gas emission tracking, where inventory compilers and atmospheric scientists work together to better understand emissions and shed light on ways to further reduce them,” said Montzka.

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