Demise of nuclear plant plans ‘devastating’ to Welsh economy, MP claims

Sulphur Hexafluoride (SF6) Emissions drive rising greenhouse gas impacts in electrical switchgear, power grids, and renewables, with extreme global warming potential, long atmospheric lifetime, and leakage risks challenging climate targets and grid decarbonization.

Key Points

SF6 emissions are leaks from electrical switchgear and grids, a high-GWP gas with ~1,000-year lifetime.

✅ 23,500x CO2 global warming potential (GWP)

✅ Leaks from switchgear, breakers, gas-insulated substations

✅ Clean air and vacuum alternatives emerging for MV/HV

Sulphur hexafluoride, or SF6, is widely used in the electrical industry to prevent short circuits and accidents.

But leaks of the little-known gas in the UK and the rest of the EU in 2017 were the equivalent of putting an extra 1.3 million cars on the road.

Levels are rising as an unintended consequence of the green energy boom and the broader global energy transition worldwide.

Cheap and non-flammable, SF6 is a colourless, odourless, synthetic gas. It makes a hugely effective insulating material for medium and high-voltage electrical installations.

It is widely used across the industry, from large power stations to wind turbines to electrical sub-stations in towns and cities.

It prevents electrical accidents and fires.

However, the significant downside to using the gas is that it has the highest global warming potential of any known substance. It is 23,500 times more warming than carbon dioxide (CO2).

Just one kilogram of SF6 warms the Earth to the same extent as 24 people flying London to New York return.

It also persists in the atmosphere for a long time, warming the Earth for at least 1,000 years.

So why are we using more of this powerful warming gas?

The way we make electricity around the world is changing rapidly, with New Zealand's push to electrify in its energy system.

Where once large coal-fired power stations brought energy to millions, the drive to combat climate change and to move away from coal means they are now being replaced by mixed sources of power including wind, solar and gas.

This has resulted in many more connections to the electricity grid, and with EU electricity use could double by 2050, a rise in the number of electrical switches and circuit breakers that are needed to prevent serious accidents.

Collectively, these safety devices are called switchgear. The vast majority use SF6 gas to quench arcs and stop short circuits.

"As renewable projects are getting bigger and bigger, we have had to use it within wind turbines specifically," said Costa Pirgousis, an engineer with Scottish Power Renewables on its new East Anglia wind farm, which doesn't use SF6 in turbines.

"As we are putting in more and more turbines, we need more and more switchgear and, as a result, more SF6 is being introduced into big turbines off shore.

"It's been proven for years and we know how it works, and as a result it is very reliable and very low maintenance for us offshore."

How do we know that SF6 is increasing?

Across the entire UK network of power lines and substations, there are around one million kilograms of SF6 installed.

A study from the University of Cardiff found that across all transmission and distribution networks, the amount used was increasing by 30-40 tonnes per year.

This rise was also reflected across Europe with total emissions from the 28 member states in 2017 equivalent to 6.73 million tonnes of CO2. That's the same as the emissions from 1.3 million extra cars on the road for a year.

Researchers at the University of Bristol who monitor concentrations of warming gases in the atmosphere say they have seen significant rises in the last 20 years.

"We make measurements of SF6 in the background atmosphere," said Dr Matt Rigby, reader in atmospheric chemistry at Bristol.

"What we've seen is that the levels have increased substantially, and we've seen almost a doubling of the atmospheric concentration in the last two decades."

How does SF6 get into the atmosphere?

The most important means by which SF6 gets into the atmosphere is from leaks in the electricity industry.

Electrical company Eaton, which manufactures switchgear without SF6, says its research indicates that for the full life-cycle of the product, leaks could be as high as 15% - much higher than many other estimates.

Louis Schaeffer, electrical business manager at Eaton, said: "The newer gear has very low leak rates but the key question is do you have newer gear?

"We looked at all equipment and looked at the average of all those leak rates, and we didn't see people taking into account the filling of the gas. Plus, we looked at how you recycle it and return it and also included the catastrophic leaks."

How damaging to the climate is this gas?

Concentrations in the atmosphere are very small right now, just a fraction of the amount of CO2 in the air.

However, the global installed base of SF6 is expected to grow by 75% by 2030, as data-driven electricity demand surges worldwide.

Another concern is that SF6 is a synthetic gas and isn't absorbed or destroyed naturally. It will all have to be replaced and destroyed to limit the impact on the climate.

Developed countries are expected to report every year to the UN on how much SF6 they use, but developing countries do not face any restrictions on use.

Right now, scientists are detecting concentrations in the atmosphere that are 10 times the amount declared by countries in their reports. Scientists say this is not all coming from countries like India, China and South Korea.

One study found that the methods used to calculate emissions in richer countries "severely under-reported" emissions over the past two decades.

Why hasn't this been banned?

SF6 comes under a group of human-produced substances known as F-gases. The European Commission tried to prohibit a number of these environmentally harmful substances, including gases in refrigeration and air conditioning, back in 2014.

But they faced strong opposition from industries across Europe.

"In the end, the electrical industry lobby was too strong and we had to give in to them," said Dutch Green MEP Bas Eickhout, who was responsible for the attempt to regulate F-gases.

"The electric sector was very strong in arguing that if you want an energy transition, and you have to shift more to electricity, you will need more electric devices. And then you also will need more SF6.

"They used the argument that otherwise the energy transition would be slowed down."

What do regulator and electrical companies say about the gas?

Everyone is trying to reduce their dependence on the gas, and US control efforts suggest targeted policies can drive declines, as it is universally recognised as harmful to the climate.

In the UK, energy regulator Ofgem says it is working with utilities to try to limit leaks of the gas.

"We are using a range of tools to make sure that companies limit their use of SF6, a potent greenhouse gas, where this is in the interest of energy consumers," an Ofgem spokesperson told BBC News.

"This includes funding innovation trials and rewarding companies to research and find alternatives, setting emissions targets, rewarding companies that beat those targets, and penalising those that miss them."

Are there alternatives - and are they very expensive?

The question of alternatives to SF6 has been contentious over recent years.

For high-voltage applications, experts say there are very few solutions that have been rigorously tested.

"There is no real alternative that is proven," said Prof Manu Haddad from the school of engineering at Cardiff University.

"There are some that are being proposed now but to prove their operation over a long period of time is a risk that many companies don't want to take."

Medium voltage operations there are several tried-and-tested materials. Some in the industry say that the conservative nature of the electrical industry is the key reason that few want to change to a less harmful alternative.

"I will tell you, everyone in this industry knows you can do this; there is not a technical reason not to do it," said Louis Schaffer from Eaton.

"It's not really economic; it's more a question that change takes effort and if you don't have to, you won't do it."

Some companies are feeling the winds of change

Sitting in the North Sea some 43km from the Suffolk coast, Scottish Power Renewables has installed one of world's biggest wind farms, in line with a sustainable electric planet vision, where the turbines will be free of SF6 gas.

East Anglia One will see 102 of these towering generators erected, with the capacity to produce up to 714MW (megawatts) of power by 2020, enough to supply half a million homes.

Previously, an installation like this would have used switchgear supplied with SF6, to prevent the electrical accidents that can lead to fires.

Each turbine would normally have contained around 5kg of SF6, which, if it leaked into the atmosphere, would add the equivalent of around 117 tonnes of carbon dioxide. This is roughly the same as the annual emissions from 25 cars.

"In this case we are using a combination of clean air and vacuum technology within the turbine. It allows us to still have a very efficient, reliable, high-voltage network but to also be environmentally friendly," said Costa Pirgousis from Scottish Power Renewables.

"Once there are viable alternatives on the market, there is no reason not to use them. In this case, we've got a viable alternative and that's why we are using it."

But even for companies that are trying to limit the use of SF6, there are still limitations. At the heart of East Anglia One sits a giant offshore substation to which all 102 turbines will connect. It still uses significant quantities of the highly warming gas.

What happens next ?

The EU will review the use of SF6 next year and will examine whether alternatives are available. However, even the most optimistic experts don't think that any ban is likely to be put in place before 2025.

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Quebec Ice Storm 2025 disrupted power across Laurentians and Lanaudiere as freezing rain downed lines; Hydro-QuE9bec crews accelerated grid restoration, emergency response, and infrastructure resilience amid ongoing outages and severe weather alerts.

Key Points

Quebec Ice Storm 2025 brought freezing rain, outages, and grid damage, hitting Laurentians and Lanaudiere hardest.

✅ Peak: 62,000 Hydro-QuE9bec customers without electricity

✅ Most outages in Laurentians and Lanaudiere regions

✅ Crews repairing lines; restoration updates ongoing

A significant weather event struck Quebec in late March 2025, as a powerful ice storm caused widespread power outages across the province. The storm led to extensive power outages, affecting tens of thousands of residents, particularly in the Lanaudière and Laurentians regions. ​

Impact on Power Infrastructure

The freezing rain accumulated on power lines and vegetation, leading to numerous power outages across the network. Hydro-Québec reported that at its peak, over 62,000 customers were without electricity, with the majority of outages concentrated in the Laurentians and Lanaudière regions. By the afternoon, the number decreased to approximately 30,000, and further to just under 18,500 by late afternoon. 

Comparison with Previous Storms

While the March 2025 ice storm caused significant disruptions, it was less severe compared to the catastrophic ice storm of April 2023, which left 1.1 million Hydro-Québec customers without power. Nonetheless, the 2025 storm's impact was considerable, leading to the closure of municipal facilities and posing challenges for local economies, a pattern echoed when Toronto outages persisted for hundreds after a spring storm.

Ongoing Challenges

As of April 1, 2025, some areas continued to experience power outages, and incidents such as a manhole fire left thousands without service in separate cases. Hydro-Québec and municipal authorities worked diligently to restore services and address the aftermath of the storm, while Hydro One crews restored power to more than 277,000 customers after damaging storms in Ontario. Residents were advised to stay updated through official channels for restoration timelines and safety information.

Future Preparedness

The recurrence of such severe weather events highlights the importance of robust infrastructure and emergency preparedness, as seen in BC Hydro's storm response to an 'atypical' event that demanded extensive coordination. Both utility companies and residents must remain vigilant, especially during seasons prone to unpredictable weather patterns, with local utilities like Sudbury Hydro crews working to reconnect service after regional storms.

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California Electricity Prices are surging across PG&E, SCE, and SDG&E territories, driven by fixed grid costs, wildfire mitigation, CARE subsidies, and Net Energy Metering, burdening low-income renters and increasing statewide utility debt, CPUC reports show.

Key Points

High rates driven by fixed grid costs and policies, burdening low-income customers across PG&E, SCE, and SDG&E.

✅ Fixed costs: transmission, distribution, wildfire mitigation

✅ Solar NEM shifts grid costs onto remaining ratepayers

✅ CPUC, CARE, LIHEAP aim to relieve rising utility debt

California's electricity prices are among the highest in the country, new research says, and those costs are falling disproportionately on a customer base that's already struggling to pay their bills.

PG&E customers pay about 80 percent more per kilowatt-hour than the national average, according to a study by the energy institute at UC Berkeley's Haas Business School with the nonprofit think tank Next 10. The study analyzed the rates of the state's three largest investor-owned utilities and found that Southern California Edison charged 45 percent more than the national average, while San Diego Gas & Electric charged double. Even low-income residents enrolled in the California Alternate Rates for Energy program paid more than the average American.

"California's retail prices are out of line with utilities across the country," said UC Berkeley assistant professor and study co-author Meredith Fowlie, citing Hawaii and some New England states among the outliers with even higher rates. "And they're increasing, as regulators face calls for action across the state."

So why are prices so high?
One reason is that California's size and geography inflate the "fixed" costs of operating its electric system, even as the state considers revamping electricity rates to clean the grid in parallel, which include maintenance, generation, transmission, and distribution as well as public programs like CARE and wildfire mitigation, according to the study. Those costs don't change based on how much electricity residents consume, yet between 66 and 77 percent of Californians' electricity bills are used to offset the costs of those programs, the study found.

These are legitimate expenses, Fowlie said. However, because lower-income residents use only moderately less electricity than higher income households, they end up with a disproportionate share of the burden, according to the study. And while the bills of older, wealthier Californians continue to decrease as they adopt cost-efficient alternatives like the state's Net Energy Metering solar program and the resulting solar power cost shift dynamic, costs will keep rising for a shrinking customer base composed mostly of low- and middle-income renters who still use electricity as their main energy source.

"When households adopt solar, they're not paying their fair share," Fowlie said. While solar users generate power that decreases their bills, they still rely on the state's electric grid for much of their power consumption - without paying for its fixed costs like others do.

"As this continues it's going to make electricity even more unaffordable," said F. Noel Perry, founder of Next 10, which funds nonpartisan research on the economy and environment.

PG&E this month raised its electricity rates 3.7 percent, amounting to a $5.01 a month increase for the average residential customer, who now pays $138.85 a month for electricity. It was the second increase this year, as regulators consider major changes to electric bills statewide, said Mark Toney, executive director of The Utility Reform Network, who noted that higher rates are particularly difficult for those who have lost their jobs in the pandemic. The California Public Utilities Commission last year approved a PG&E plan for more incremental increases through Dec. 31, 2022.

PG&E spokesperson Kristi Jourdan said in an email statement that the company was committed to keeping prices as low as possible as the state weighs income-based flat-fee utility bills proposals, and that although some programs are meant to be subsidized through rates, "in other cases, given that some customers have greater access to energy alternatives, the remaining customers - often those with limited means - are left paying unintended subsidies."

The costs quickly became overwhelming for Fretea Sylver, who rents a small house in Castro Valley and lost much of her work as the owner of a small woodwork business early in the pandemic. "They're little tiny changes but they accumulate. You turn around and you're like wait a second, why is my bill $20 more?," Sylver said. "And you have to pay it, no matter what."

Many more are unable to pay. Between February and December of last year, Californians accumulated more than $650 million in late payments from their utility providers, according to an analysis by the CPUC. In 2019, utility debt fell $71,646,869 from the prior year.

Sylver, who was on unemployment for 10 months last year, accumulated over $600 in unpaid PG&E bills. "We sort of went into a bit of debt, having to use credit cards and loans to sustain what we had to pay for. We're trying to catch up," Sylver said. The family received some help from the federal Low-Income Home Energy Assistance Program, which provides up to $1,000 to those who are late on their utility bills.

The study identified improvements to make California's power grid more equitable, such as income-based fixed electricity charges for the grid's cost that are based on income. Republican state senators this week called on the state to use federal relief money to forgive the billions Californians owe in utility debt, even as some lawmakers move to overturn income-based utility charges amid ongoing debate. Californians are currently protected by a statewide moratorium on disconnection for nonpayment of electricity bills through June 30. The CPUC this month began taking public input on the issue of how to grant some relief to those who have fallen behind on their utility bills.

This article is part of the California Divide, a collaboration among newsrooms examining income inequality and economic survival in California.

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Skinners Pond Transmission Line expands PEI's renewable energy grid, enabling wind power integration, grid reliability, and capacity for the planned 40 MW windfarm, funded through the Green Infrastructure Stream to support sustainable economic growth.

Key Points

A 106-km grid project enabling PEI wind power, increasing capacity and reliability, linking Skinners Pond to Sherbrooke.

✅ 106-km line connects Skinners Pond to Sherbrooke substation

✅ Integrates 40 MW windfarm capacity by 2025

✅ Funded by Canada and PEI via Green Infrastructure Stream

The health and well-being of Canadians are the top priorities of the Governments of Canada and Prince Edward Island. But the COVID-19 pandemic has affected more than Canadians' personal health. It is having a profound effect on the economy.

That is why governments have been taking decisive action together to support families, businesses and communities, and continue to look ahead to planning for our electricity future and see what more can be done.

Today, Bobby Morrissey, Member of Parliament for Egmont, on behalf of the Honourable Catherine McKenna, Minister of Infrastructure and Communities, the Honourable Dennis King, Premier of Prince Edward Island, the Honourable Dennis King, Premier of Prince Edward Island, and the Honourable Steven Myers, Prince Edward Island Minister of Transportation, Infrastructure and Energy, announced funding to build a new transmission line from Sherbrooke to Skinners Pond, as part of broader Canadian collaboration on clean energy, with several premiers nuclear reactor technology to support future needs as well.

The new 106-kilometre transmission line and its related equipment will support future wind energy generation projects in western Prince Edward Island, complementing the Eastern Kings wind farm expansion already advancing. Once completed, the transmission line will increase the province's capacity to manage the anticipated 40 megawatts from the future Skinner's Pond Windfarm planned for 2025 and provide connectivity to the Sherbrooke substation to the northeast of Summerside.

The Government of Canada is investing $21.25 million and the Government of Prince Edward Island is providing $22.75 million in this project, reflecting broader investments in new turbines across Canada, through the Green Infrastructure Stream (GIS) of the Investing in Canada infrastructure program.

This projects is one in a series of important project announcements that will be made across the province over the coming weeks. The Governments of Canada and Prince Edward Island are working cooperatively to support jobs, improve communities and build confidence, while safely and sustainably restoring economic growth, as Nova Scotia increases wind and solar projects across the region.

"Investing in renewable energy infrastructure is essential to building healthy, inclusive, and resilient communities. The new Skinners Pond transmission line will support Prince Edward Island's production of green energy, focusing on wind resources rather than expanded biomass use in the mix. Projects like this also support economic growth and help us build a greener future for the next generation of Islanders."

Bobby Morrissey, Member of Parliament for Egmont, on behalf of the Honourable Catherine McKenna, Minister of Infrastructure and Communities

"We live on an Island that has tremendous potential in further developing renewable energy. We have an opportunity to become more sustainable and be innovative in our approach, and learn from regions where provinces like Manitoba have clean energy to help neighbouring provinces through interties. The strategic investment we are making today in the Skinner's Pond transmission line will allow Prince Edward Island to further harness the natural power of wind to create clean, locally produced and locally used energy that will benefit of all Islanders."

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Hydro-Quebec NECEC Transmission Line faces Maine PUC scrutiny over clean energy claims, greenhouse gas emissions, spillage capacity, resource shuffling, and Massachusetts contracts, amid opposition from natural gas generators and environmental groups debating public need.

Key Points

A $1B Maine corridor for Quebec hydropower to Massachusetts, debated over emissions, spillage, and public need.

✅ Maine PUC weighing public need and ratepayer benefits

✅ Emissions impact disputed: resource shuffling vs new supply

✅ Hydro-Quebec spillage claims questioned without data

As Maine regulators are deciding whether to approve construction of a $1 billion electricity corridor across much of western Maine, the Canadian hydroelectric utility poised to make billions of dollars from the project has been absent from the process.

This has left both opponents and supporters of the line arguing about how much available energy the utility has to send through a completed line, and whether that energy will help fulfill the mission of the project: fighting climate change.

And while the utility has avoided making its case before regulators, which requires submitting to cross-examination and discovery, it has engaged in a public relations campaign to try and win support from the region's newspapers.

Government-owned Hydro-Quebec controls dams and reservoirs generating hydroelectricity throughout its namesake province. It recently signed agreements to sell electricity across the proposed line, named the New England Clean Energy Connect, to Massachusetts as part of the state's effort to reduce its dependence on fossil fuels, including natural gas.

At the Maine Public Utilities Commission, attorneys for Central Maine Power Co., which would build and maintain the line, have been sparring with the opposition over the line's potential impact on Maine and its electricity consumers. Leading the opposition is a coalition of natural gas electricity generators that stand to lose business should the line be built, as well as the Natural Resources Council of Maine, an environmental group.

That unusual alliance of environmental and business groups wants Hydro-Quebec to answer questions about its hydroelectric system, which they argue can't deliver the amount of electricity promised to Massachusetts without diverting energy from other regions.

In that scenario, critics say the line would not produce the reduction in greenhouse gas emissions that CMP and Hydro-Quebec have made a central part of their pitch for the project. Instead, other markets currently buying energy from Hydro-Quebec, such as New York, Ontario and New Brunswick, would see hydroelectricity imports decrease and have to rely on other sources of energy, including coal or oil, to make up the difference. If that happened, the total amount of clean energy in the world would remain the same.

Opponents call this possibility "greenwashing." Massachusetts regulators have described these circumstances as "resource shuffling."

But CMP spokesperson John Carroll said that if hydropower was diverted from nearby markets to power Massachusetts, those markets would not turn to fossil fuels. Rather they would seek to develop other forms of renewable energy "leading to further reductions in greenhouse gas emissions in the region."

Hydro-Quebec said it has plenty of capacity to increase its electricity exports to Massachusetts without diverting energy from other places.

However, Hydro-Quebec is not required to participate -- and has not voluntarily participated -- in regulatory hearings where it would be subject to cross examinations and have to testify under oath. Some participants wish it would.

At a January hearing at the Maine Public Utilities Commission, hearing examiner Mitchell Tannenbaum had to warn experts giving testimony to "refrain from commentary regarding whether Hydro-Quebec is here or not" after they complained about its absence when trying to predict potential ramifications of the line.

"I would have hoped they would have been visible and available to answer legitimate questions in all of these states through which their power is going to be flowing," said Dot Kelly, a member of the executive committee at the Maine Chapter of the Sierra Club who has participated in the line's regulatory proceedings as an individual. "If you're going to have a full and fair process, they have to be there."

[What you need to know about the CMP transmission line proposed for Maine]

While Hydro-Quebec has not presented data on its system directly to Maine regulators, it has brought its case to the press. Central to that case is the fact that it's "spilling" water from its reservoirs because it is limited by how much electricity it can export. It said that it could send more water through its turbines and lower reservoir levels, eliminating spillage and creating more energy, if only it had a way to get that energy to market. Hydro-Quebec said the line would make that possible, and, in doing so, help lower emissions and fight climate change.

"We have that excess potential that we need to use. Essentially, it's a good problem to have so long as you can find an export market," Hydro-Quebec spokesperson Serge Abergel told the Bangor Daily News.

Hydro-Quebec made its "spillage" case to the editorial boards of The Boston Globe, The Portland Press Herald and the BDN, winning qualified endorsements from the Globe and Press Herald. (The BDN editorial board has not weighed in on the project).

Opponents have questioned why Hydro-Quebec is willing to present their case to the press but not regulators.

"We need a better answer than 'just trust us,'" Natural Resources Council of Maine attorney Sue Ely said. "What's clear is that CMP and HQ are engaging in a full-court publicity tour peddling false transparency in an attempt to sell their claims of greenhouse gas benefits."

Energy generators aren't typically parties to public utility commission proceedings involving the building of transmission lines, but Maine regulators don't typically evaluate projects that will help customers in another state buy energy generated in a foreign country.

"It's a unique case," said Maine Public Advocate and former Democratic Senate Minority Leader Barry Hobbins, who has neither endorsed nor opposed the project. Hobbins noted the project was not proposed to improve reliability for Maine electricity customers, which is typically the point of new transmission line proposals evaluated by the commission. Instead, the project "is a straight shot to Massachusetts," Hobbins said.

Maine Public Utilities Commission spokesperson Harry Lanphear agreed. "The Commission has never considered this type of project before," he said in an email.

In order to proceed with the project, CMP must convince the Maine Public Utilities Commission that the proposed line would fill a "public need" and benefit Mainers. Among other benefits, CMP said it will help lower electricity costs and create jobs in Maine. A decision is expected in the spring.

Given the uniqueness of the case, even the commission seems unsure about how to apply the vague "public need" standard. On Jan. 14, commission staff asked case participants to weigh in on how it should apply Maine law when evaluating the project, including whether the hydroelectricity that would travel over the line should be considered "renewable" and whether Maine's own carbon reduction goals are relevant to the case.

James Speyer, an energy consultant whose firm was hired by natural gas company and project opponent Calpine to analyze the market impacts of the line, said he has testified before roughly 20 state public utility commissions and has never seen a proceeding like this one.

"I've never been in a case where one of the major beneficiaries of the PUC decision is not in the case, never has filed a report, has never had to provide any data to support its assertions, and never has been subject to cross examination," Speyer said. "Hydro-Quebec is like a black box."

Hydro-Quebec would gladly appear before the Maine Public Utilities Commission, but it has not been invited, said spokesperson Abergel.

"The PUC is doing its own process," Abergel said. "If the PUC were to invite us, we'd gladly intervene. We're very willing to collaborate in that sense."

But that's not how the commission process works. Individuals and organizations can intervene in cases, but the commission does not invite them to the proceedings, commission spokesperson Lanphear said.

CMP spokesperson Carroll dismissed concerns over emissions, noting that Hydro-Quebec is near the end of completing a more than 15-year effort to develop its clean energy resources. "They will have capacity to satisfy the contract with Massachusetts in their reservoirs," Carroll said.

While Maine regulators are evaluating the transmission line, Massachusetts' Department of Public Utilities is deciding whether to approve 20-year contracts between Hydro-Quebec and that state's electric utilities. Those contracts, which Hydro-Quebec has estimated could be worth close to $8 billion, govern how the utility sells electricity over the line.

Dean Murphy, a consultant hired by the Massachusetts Attorney General's office to review the contracts, testified before Massachusetts regulators that the agreements do not require a reduction in global greenhouse gas emissions. Murphy also warned the contracts don't actually require Hydro-Quebec to increase the total amount of energy it sends to New England, as energy could be shuffled from established lines to the proposed CMP line to satisfy the contracts.

Parties in the Massachusetts proceeding are also trying to get more information from Hydro-Quebec. Energy giant NextEra is currently trying to convince Massachusetts regulators to issue a subpoena to force Hydro-Quebec to answer questions about how its exports might change with the construction of the transmission line. Hydro-Quebec and CMP have opposed the motion.

Hydro-Quebec has a reputation for guarding its privacy, according to Hobbins.

"It would have been easier to not have to play Sherlock Holmes and try to guess or try to calculate without having a direct 'yes' or 'no' response from the entity itself," Hobbins said.

Ultimately, the burden of proving that Maine needs the line falls on CMP, which is also responsible for making sure regulators have all the information they need to make a decision on the project, said former Maine Public Utilities Commission Chairman Kurt Adams.

"Central Maine Power should provide the PUC with all the info that it needs," Adams said. "If CMP can't, then one might argue that they haven't met their burden."

'They treat HQ with nothing but distrust'

If completed, the line would bring 9.45 terawatt hours of electricity from Quebec to Massachusetts annually, or about a sixth of the total amount of electricity Massachusetts currently uses every year (and roughly 80 percent of Maine's annual load). CMP's parent company Avangrid would make an estimated $60 million a year from the line, according to financial analysts.

As part of its legally mandated efforts to reduce carbon emissions and fight climate change, Massachusetts would pay the $950 million cost of constructing the line. The state currently relies on natural gas, a fossil fuel, for nearly 70 percent of its electricity, a figure that helps explain natural gas companies' opposition to the project.

A panel of experts recently warned that humanity has 12 years to keep global temperatures from rising above 1.5 degrees Celsius and prevent the worst effects of climate change, which include floods, droughts and extreme heat.

The line could lower New England's annual carbon emissions by as much as 3 million metric tons, an amount roughly equal to Washington D.C.'s annual emissions. Opponents worry that reduction could be mostly offset by increases in other markets.

But while both sides have claimed they are fighting for the environment, much of the debate features giant corporations with headquarters outside of New England fighting over the future of the region's electricity market, echoing customer backlash seen in other utility takeovers.

Hydro-Quebec is owned by the people of Quebec, and CMP is owned by Avangrid, which is in turn owned by Spanish energy giant Iberdrola. Leading the charge against the line are several energy companies in the Fortune 500, including Houston-based Calpine and Florida-based NextEra Energy.

However, only one side of the debate counts environmental groups as part of its coalition, and, curiously enough, that's the side with fossil fuel companies.

Some environmental groups, including the Natural Resources Council of Maine and Environment Maine, have come out against the line, while others, including the Acadia Center and the Conservation Law Foundation, are still deciding whether to support or oppose the project. So far, none have endorsed the line.

"It is discouraging that some of the environmental groups are so opposed, but it seems the best is the enemy of the good," said CMP's Carroll in an email. "They seem to have no sense of urgency; and they treat HQ with nothing but distrust."

Much of the environmentally minded opposition to the project focuses on the impact the line would have on local wildlife and tourism.

Sandi Howard administers the Say NO To NECEC Facebook page and lives in Caratunk, one of the communities along the proposed path of the line. She said opposition to the line might change if it was proven to reduce emissions.

"If it were going to truly reduce global CO2 emissions, I think it would be be a different conversation," Howard said.

Not the first choice

Before Maine, New Hampshire had its own debate over whether it should serve as a conduit between Quebec and Massachusetts. The proposed Northern Pass transmission line would have run the length of the state. It was Massachusetts' first choice to bring Quebec hydropower to its residents.

But New Hampshire's Site Evaluation Committee unanimously voted to reject the Northern Pass project in February 2018 on the grounds that the project's sponsor, Eversource, had failed to prove the project would not interfere with local business and tourism. Though it was the source of the electricity that would have traveled over the line, Hydro-Quebec was not a party to the proceedings.

In its decision, the committee noted the project would not reduce emissions if it was not coupled with a "new source of hydropower" and the power delivered across the line was "diverted from Ontario and New York." The committee added that it was unclear if the power would be new or diverted.

The next month, Massachusetts replaced Northern Pass by selecting CMP's proposed line. As the project came before Maine regulators, questions about Hydro-Quebec and emissions persisted. Two different analyses of CMP's proposed line, including one by the Maine Public Utility Commission's independent consultant, found the line would greatly reduce New England's emissions.

But neither of those studies took into account the line's impact on emissions outside of New England. A study by Calpine's consultant, Energyzt, found New England's emissions reduction could be mostly offset by increased emissions in other areas, including New Brunswick and New York, that would see hydroelectricity imports shrink as energy was redirected to fulfill the contract with Massachusetts.

'They failed in any way to back up those spillage claims'

Hydro-Quebec seemed content to let CMP fight for the project alone before regulators for much of 2018. But at the end of the year, the utility took a more proactive approach, meeting with editorial boards and providing a two-page letter detailing its "spillage" issues to CMP, which entered it into the record at the Maine Public Utilities Commission.

The letter provided figures on the amount of water the utility spilled that could have been converted into sellable energy, if only Hydro-Quebec had a way to get it to market. Instead, by "spilling" the water, the company essentially wasted it.

Instead of sending water through turbines or storing it in reservoirs, hydroelectric operators sometimes discharge water held behind dams down spillways. This can be done for environmental reasons. Other times it is done because the operator has so much water it cannot convert it into electricity or store it, which is usually a seasonal issue: Reservoirs often contain the most water in the spring as temperatures warm and ice melts.

Hydro-Quebec said that, in 2017, it spilled water that could have produced 4.5 terawatt hours of electricity, or slightly more than half the energy needed to fulfill the Massachusetts contracts. In 2018, the letter continued, Hydro-Quebec spilled water that could have been converted into 10.4 terawatts worth of energy. The company said it didn't spill at all due to transmission constraints prior to 2017.

The contracts Hydro-Quebec signed with the Massachusetts utilities are for 9.45 terawatt hours annually for 20 years. In its letter, the utility essentially showed it had only one year of data to show it could cover the terms of the contract with "spilled" energy.

"Reservoir levels have been increasing in the last 15 years. Having reached their maximum levels, spillage maneuvers became necessary in 2017 and 2018," said Hydro-Quebec spokesperson Lynn St. Laurent.

By providing the letter through CMP, Hydro-Quebec did not have to subject its spillage figures to cross examination.

Dr. Shaleen Jain, a civil and environmental engineering professor at the University of Maine, said that, while spilled water could be converted into power generation in some circumstances, spills happen for many different reasons. Knowing whether spillage can be translated into energy requires a great deal of analysis.

"Not all of it can be repurposed or used for hydropower," Jain said.

In December, one of the Maine Public Utility Commission's independent consultants, Gabrielle Roumy, told the commission that there's "no way" to "predict how much water would be spilled each and every year." Roumy, who previously worked for Hydro-Quebec, added that even after seeing the utility's spillage figures, he believed it would need to divert energy from other markets to fulfill its commitment to Massachusetts.

"I think at this point we're still comfortable with our assumptions that, you know, energy would generally be redirected from other markets to NECEC if it were built," Roumy said.

In January, Tanya Bodell, the founder and executive director of consultant Energyzt, testified before the commission on behalf of Calpine that it was impossible to know why Hydro-Quebec was spilling without more data.

"There's a lot of details you'd have to look at in order to properly assess what the reason for the spillage is," Bodell said. "And you have to go into an hourly level because the flows vary across the year, within the month, the week, the days. ...And, frankly, it would have been nice if Hydro-Quebec was here and brought their model and allowed us to see how this could help them to sell more."

Even though CMP and Hydro-Quebec's path to securing approval of the project does not go through the Legislature, and despite a Maine court ruling that energized Hydro-Quebec's export bid, lawmakers have taken notice of Hydro-Quebec's absence. Rep. Seth Berry, D-Bowdoinham, the House chairman of the Joint Committee On Energy Utilities and Technology and a frequent critic of CMP, said he would like to see Hydro-Quebec "show up and subject their proposal to examination and full analysis and public examination by the regulators and the people of Maine."

"They're trying to sell an incredibly lucrative proposal, and they failed in any way to back up those spillage claims with defensible numbers and defensible analysis," Berry said.

Berry was part of a bipartisan group of Maine lawmakers that wrote a letter to Massachusetts regulators last year expressing concerns about the project, which included doubts about whether the line would actually reduce global gas emissions. On Monday, he announced legislation that would direct the state to create an independent entity to buy out CMP from its foreign investors.

'No benefit to remaining quiet'

Hydro-Quebec would like to provide answers, but "there is always a commercially sensitive information concern when we do these things," said spokesperson Abergel.

"There might be stuff we can do, having an independent study that looks at all of this. I'm not worried about the conclusion," Abergel said. "I'm worried about how long it takes."

Instead of asking Hydro-Quebec questions directly, participants in both Maine and Massachusetts regulatory proceedings have had to direct questions for Hydro-Quebec to CMP. That arrangement may be part of Hydro-Quebec's strategy to control its information, said former Maine Public Utilities Commissioner David Littell.

"From a tactical point of view, it may be more beneficial for the evidence to be put through Avangrid and CMP, which actually doesn't have that back-up info, so can't provide it," Littell said.

Getting information about the line from CMP, and its parent company Avangrid, has at times been difficult, opponents say.

In August 2018, the commission's staff warned CMP in a legal filing that it was concerned "about what appears to be a lack of completeness and timeliness by CMP/Avangrid in responding to data requests in this proceeding."

The trouble in getting information from Hydro-Quebec and CMP only creates more questions for Hydro-Quebec, said Jeremy Payne, executive director of the Maine Renewable Energy Association, which opposes the line in favor of Maine-based renewables.

"There's a few questions that should have relatively simple answers. But not answering a couple of those questions creates more questions," Payne said. "Why didn't you intervene in the docket? Why are you not a party to the case? Why won't you respond to these concerns? Why wouldn't you open yourself up to discovery?"

"I don't understand why they won't put it to bed," Payne said. "If you've got the proof to back it up, then there's no benefit to remaining quiet."

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Boeing 787 More-Electric Architecture replaces pneumatics with bleedless pressurization, VFSG starter-generators, electric brakes, and heated wing anti-ice, leveraging APU, RAT, batteries, and airport ground power for efficient, redundant electrical power distribution.

Key Points

An integrated, bleedless electrical system powering start, pressurization, brakes, and anti-ice via VFSGs, APU and RAT.

✅ VFSGs start engines, then generate 235Vac variable-frequency power

✅ Bleedless pressurization, electric anti-ice improve fuel efficiency

✅ Electric brakes cut hydraulic weight and simplify maintenance

The 787 Dreamliner is different to most commercial aircraft flying the skies today. On the surface it may seem pretty similar to the likes of the 777 and A350, but get under the skin and it’s a whole different aircraft.

When Boeing designed the 787, in order to make it as fuel efficient as possible, it had to completely shake up the way some of the normal aircraft systems operated. Traditionally, systems such as the pressurization, engine start and wing anti-ice were powered by pneumatics. The wheel brakes were powered by the hydraulics. These essential systems required a lot of physical architecture and with that comes weight and maintenance. This got engineers thinking.

What if the brakes didn’t need the hydraulics? What if the engines could be started without the pneumatic system? What if the pressurisation system didn’t need bleed air from the engines? Imagine if all these systems could be powered electrically… so that’s what they did.

Power sources

The 787 uses a lot of electricity. Therefore, to keep up with the demand, it has a number of sources of power, much as grid operators track supply on the GB energy dashboard to balance loads. Depending on whether the aircraft is on the ground with its engines off or in the air with both engines running, different combinations of the power sources are used.

Engine starter/generators

The main source of power comes from four 235Vac variable frequency engine starter/generators (VFSGs). There are two of these in each engine. These function as electrically powered starter motors for the engine start, and once the engine is running, then act as engine driven generators.

The generators in the left engine are designated as L1 and L2, the two in the right engine are R1 and R2. They are connected to their respective engine gearbox to generate electrical power directly proportional to the engine speed. With the engines running, the generators provide electrical power to all the aircraft systems.

APU starter/generators

In the tail of most commercial aircraft sits a small engine, the Auxiliary Power Unit (APU). While this does not provide any power for aircraft propulsion, it does provide electrics for when the engines are not running.

The APU of the 787 has the same generators as each of the engines — two 235Vac VFSGs, designated L and R. They act as starter motors to get the APU going and once running, then act as generators. The power generated is once again directly proportional to the APU speed.

The APU not only provides power to the aircraft on the ground when the engines are switched off, but it can also provide power in flight should there be a problem with one of the engine generators.

Battery power

The aircraft has one main battery and one APU battery. The latter is quite basic, providing power to start the APU and for some of the external aircraft lighting.

The main battery is there to power the aircraft up when everything has been switched off and also in cases of extreme electrical failure in flight, and in the grid context, alternatives such as gravity power storage are being explored for long-duration resilience. It provides power to start the APU, acts as a back-up for the brakes and also feeds the captain’s flight instruments until the Ram Air Turbine deploys.

Ram air turbine (RAT) generator

When you need this, you’re really not having a great day. The RAT is a small propeller which automatically drops out of the underside of the aircraft in the event of a double engine failure (or when all three hydraulics system pressures are low). It can also be deployed manually by pressing a switch in the flight deck.

Once deployed into the airflow, the RAT spins up and turns the RAT generator. This provides enough electrical power to operate the captain’s flight instruments and other essentials items for communication, navigation and flight controls.

External power

Using the APU on the ground for electrics is fine, but they do tend to be quite noisy. Not great for airports wishing to keep their noise footprint down. To enable aircraft to be powered without the APU, most big airports will have a ground power system drawing from national grids, including output from facilities such as Barakah Unit 1 as part of the mix. Large cables from the airport power supply connect 115Vac to the aircraft and allow pilots to shut down the APU. This not only keeps the noise down but also saves on the fuel which the APU would use.

The 787 has three external power inputs — two at the front and one at the rear. The forward system is used to power systems required for ground operations such as lighting, cargo door operation and some cabin systems. If only one forward power source is connected, only very limited functions will be available.

The aft external power is only used when the ground power is required for engine start.

Circuit breakers

Most flight decks you visit will have the back wall covered in circuit breakers — CBs. If there is a problem with a system, the circuit breaker may “pop” to preserve the aircraft electrical system. If a particular system is not working, part of the engineers procedure may require them to pull and “collar” a CB — placing a small ring around the CB to stop it from being pushed back in. However, on the 787 there are no physical circuit breakers. You’ve guessed it, they’re electric.

Within the Multi Function Display screen is the Circuit Breaker Indication and Control (CBIC). From here, engineers and pilots are able to access all the “CBs” which would normally be on the back wall of the flight deck. If an operational procedure requires it, engineers are able to electrically pull and collar a CB giving the same result as a conventional CB.

Not only does this mean that the there are no physical CBs which may need replacing, it also creates space behind the flight deck which can be utilised for the galley area and cabin.

A normal flight

While it’s useful to have all these systems, they are never all used at the same time, and, as the power sector’s COVID-19 mitigation strategies showed, resilience planning matters across operations. Depending on the stage of the flight, different power sources will be used, sometimes in conjunction with others, to supply the required power.

On the ground

When we arrive at the aircraft, more often than not the aircraft is plugged into the external power with the APU off. Electricity is the blood of the 787 and it doesn’t like to be without a good supply constantly pumping through its system, and, as seen in NYC electric rhythms during COVID-19, demand patterns can shift quickly. Ground staff will connect two forward external power sources, as this enables us to operate the maximum number of systems as we prepare the aircraft for departure.

Whilst connected to the external source, there is not enough power to run the air conditioning system. As a result, whilst the APU is off, air conditioning is provided by Preconditioned Air (PCA) units on the ground. These connect to the aircraft by a pipe and pump cool air into the cabin to keep the temperature at a comfortable level.

APU start

As we near departure time, we need to start making some changes to the configuration of the electrical system. Before we can push back , the external power needs to be disconnected — the airports don’t take too kindly to us taking their cables with us — and since that supply ultimately comes from the grid, projects like the Bruce Power upgrade increase available capacity during peaks, but we need to generate our own power before we start the engines so to do this, we use the APU.

The APU, like any engine, takes a little time to start up, around 90 seconds or so. If you remember from before, the external power only supplies 115Vac whereas the two VFSGs in the APU each provide 235Vac. As a result, as soon as the APU is running, it automatically takes over the running of the electrical systems. The ground staff are then clear to disconnect the ground power.

If you read my article on how the 787 is pressurised, you’ll know that it’s powered by the electrical system. As soon as the APU is supplying the electricity, there is enough power to run the aircraft air conditioning. The PCA can then be removed.

Engine start

Once all doors and hatches are closed, external cables and pipes have been removed and the APU is running, we’re ready to push back from the gate and start our engines. Both engines are normally started at the same time, unless the outside air temperature is  below 5°C.

On other aircraft types, the engines require high pressure air from the APU to turn the starter in the engine. This requires a lot of power from the APU and is also quite noisy. On the 787, the engine start is entirely electrical.

Power is drawn from the APU and feeds the VFSGs in the engines. If you remember from earlier, these fist act as starter motors. The starter motor starts the turn the turbines in the middle of the engine. These in turn start to turn the forward stages of the engine. Once there is enough airflow through the engine, and the fuel is igniting, there is enough energy to continue running itself.

After start

Once the engine is running, the VFSGs stop acting as starter motors and revert to acting as generators. As these generators are the preferred power source, they automatically take over the running of the electrical systems from the APU, which can then be switched off. The aircraft is now in the desired configuration for flight, with the 4 VFSGs in both engines providing all the power the aircraft needs.

As the aircraft moves away towards the runway, another electrically powered system is used — the brakes. On other aircraft types, the brakes are powered by the hydraulics system. This requires extra pipe work and the associated weight that goes with that. Hydraulically powered brake units can also be time consuming to replace.

By having electric brakes, the 787 is able to reduce the weight of the hydraulics system and it also makes it easier to change brake units. “Plug in and play” brakes are far quicker to change, keeping maintenance costs down and reducing flight delays.

In-flight

Another system which is powered electrically on the 787 is the anti-ice system. As aircraft fly though clouds in cold temperatures, ice can build up along the leading edge of the wing. As this reduces the efficiency of the the wing, we need to get rid of this.

Other aircraft types use hot air from the engines to melt it. On the 787, we have electrically powered pads along the leading edge which heat up to melt the ice.

Not only does this keep more power in the engines, but it also reduces the drag created as the hot air leaves the structure of the wing. A double win for fuel savings.

Once on the ground at the destination, it’s time to start thinking about the electrical configuration again. As we make our way to the gate, we start the APU in preparation for the engine shut down. However, because the engine generators have a high priority than the APU generators, the APU does not automatically take over. Instead, an indication on the EICAS shows APU RUNNING, to inform us that the APU is ready to take the electrical load.

Shutdown

With the park brake set, it’s time to shut the engines down. A final check that the APU is indeed running is made before moving the engine control switches to shut off. Plunging the cabin into darkness isn’t a smooth move. As the engines are shut down, the APU automatically takes over the power supply for the aircraft. Once the ground staff have connected the external power, we then have the option to also shut down the APU.

However, before doing this, we consider the cabin environment. If there is no PCA available and it’s hot outside, without the APU the cabin temperature will rise pretty quickly. In situations like this we’ll wait until all the passengers are off the aircraft until we shut down the APU.

Once on external power, the full flight cycle is complete. The aircraft can now be cleaned and catered, ready for the next crew to take over.

Bottom line

Electricity is a fundamental part of operating the 787. Even when there are no passengers on board, some power is required to keep the systems running, ready for the arrival of the next crew. As we prepare the aircraft for departure and start the engines, various methods of powering the aircraft are used.

The aircraft has six electrical generators, of which only four are used in normal flights. Should one fail, there are back-ups available. Should these back-ups fail, there are back-ups for the back-ups in the form of the battery. Should this back-up fail, there is yet another layer of contingency in the form of the RAT. A highly unlikely event.

The 787 was built around improving efficiency and lowering carbon emissions whilst ensuring unrivalled levels safety, and, in the wider energy landscape, perspectives like nuclear beyond electricity highlight complementary paths to decarbonization — a mission it’s able to achieve on hundreds of flights every single day.

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