This text was printed in partnership with Inside Local weather Information, a nonprofit, impartial information outlet that covers local weather, vitality and the setting.
DAVIDSON, N.C. — 4 skinny, steel cylinders containing the world’s most potent greenhouse gasoline stand lashed to the bottom of a Duke Power substation on a quiet nation street. The tanks are made to carry sulfur hexafluoride (SF6), {an electrical} insulator that was as soon as used to fill race automobile tires, tennis balls and even Nike Air Max sneakers.
A single pound of SF6 heats the planet as a lot as 25,200 kilos of carbon dioxide and stays within the environment for 3,200 years, based on the United Nation’s Intergovernmental Panel on Local weather Change. SF6 is one in every of a number of long-lived, artificial, fluorine-containing chemical compounds which can be launched by heavy {industry}, chemical producers, semiconductor-makers and electrical utilities based on the U.S. Environmental Safety Company.
The EPA, which doesn’t regulate emissions of any of those potent greenhouse gases, notes that after they’re launched, they’re “basically everlasting additions to the environment.”
In 2020, Duke Power, which supplies electrical energy in six states, leaked practically 11 metric tons of SF6 into the environment from its electrical substations in North and South Carolina alone, greater than every other utility within the nation, based on obligatory studies the corporate recordsdata with the EPA every year, reviewed by Inside Local weather Information. The emissions had been equal to the annual greenhouse gasoline emissions of greater than 59,000 vehicles, based on the EPA’s greenhouse gasoline equivalency calculator.
Jeff Brooks, a spokesperson for Duke Power, based mostly a half-hour south of right here in Charlotte, stated a attainable purpose the corporate’s emissions had been larger than all different utilities in 2020 could also be a mirrored image of how typically Duke Power inspects gear and refills leaked gasoline relative to different firms. If, for instance, Duke Power solely refilled leaked gasoline on a person piece of kit each 5 years whereas different firms refilled leaked gasoline each two years, Duke would report 5 years value of emissions for that piece of kit for the 12 months it was refilled, whereas different firms would solely report two years value of emissions, Brooks stated.
Underneath such a situation Duke Power would possible have years of low emissions punctuated by a single 12 months of excessive emissions. Nonetheless, this isn’t the case. SF6 emissions from Duke Power’s North and South Carolina electrical utilities have been the very best of any electrical energy firm within the nation for six of the final seven years, based on firm information reported to the EPA.
Whereas different utilities have participated for many years in a voluntary program with the EPA to cut back SF6 emissions to subsequent to nothing, Duke Power has not. Duke Power’s leak fee in North and South Carolina, the place it studies mixed emissions from subsidiaries Duke Power Carolinas and Duke Power Progress as a single entity, was 5.2% in 2020, or greater than 5 instances larger than the common leak fee of utilities that take part within the EPA’s voluntary emissions discount program.
Primarily based on emissions information Duke Power reported to the EPA, the 2 utilities emitted 119 tons of SF6 within the final decade alone, the greenhouse gasoline equal of greater than half one million vehicles over a one-year interval.
Brooks stated the corporate is presently changing older gear throughout all six states that it serves as a part of a grid strengthening and resiliency initiative. The initiative will change older, Nineteen Seventies-era circuit breakers that use SF6 and are extra leak-prone, with newer, extra leak-resistant gear that also makes use of SF6. Brooks stated Duke Power can also be concentrating on its most leaky gear for sooner alternative.
Brooks stated he didn’t know why Duke Power, the most important electrical energy company within the U.S. based mostly on income, wasn’t a part of the EPA-industry partnership however stated his firm was “open to evaluating it.”
The main customers, and emitters, of sulfur hexafluoride are electrical utilities that use the gasoline as an insulator to stop electrical gear from arcing, or sending an electrical present leaping by way of the air, and in high-voltage circuit breakers to rapidly interrupt electrical present. The gasoline is housed in pressurized tanks at utility substations, and a small quantity is usually emitted both by way of gear leaks or improper dealing with throughout servicing or disposal of the gasoline.
Electrical utilities typically use the transportable SF6 cylinders to refill, or “top-up,” leaking electrical gear, based on the EPA. Duke Power confirmed that the cylinders at its substation in Davidson held SF6 however wouldn’t say why they had been on the substation or whether or not they had been full or empty. “We generally stage cylinders at our websites for upcoming gear commissioning or upkeep,” Brooks stated.
Now, the 88 utilities which can be present members of the EPA emissions discount program, representing practically half of the U.S. electrical grid, are eyeing methods to remove SF6 emissions totally.
Except the speed at which utilities leak SF6 decreases, U.S. emissions will possible develop together with the electrical grid. Current research counsel the electrical grid should enhance its transmission capability to 2 to 5 instances its present stage by midcentury if the U.S. is to fulfill its net-zero emissions objectives.
Current research counsel the electrical grid should enhance its transmission capability to 2 to 5 instances its present stage by midcentury if the U.S. is to fulfill its net-zero emissions objectives.
And simply as Duke Power lags its friends within the electrical energy {industry} in decreasing its emissions of SF6, the U.S. lags different nations. Europe and Japan have adopted SF6 emission discount measures to the “best extent attainable,” a 2013 EPA report concluded, whereas the U.S. has “vital potential for reductions.”
In 2009, the EPA decided that SF6 threatened “the general public well being and welfare of present and future generations” in a part of a sweeping “endangerment discovering” on greenhouse gases. 13 years later, the company continues to depend on voluntary measures for SF6 emission reductions.
Sally Rand, a former EPA official who led the company’s voluntary partnerships with {industry} that helped scale back emissions within the Nineties and early 2000s, and different former EPA officers say it’s time to re-engage {industry} and redouble efforts to remove the remaining fluorinated gasoline emissions.
“They deserted the partnerships early,” stated Stephen Andersen, director of analysis on the Institute for Governance and Sustainable Improvement and a former EPA official who pioneered the company’s {industry} partnerships. “It was a horrible mistake.”
Molecules that ‘dwell ceaselessly’
Within the early Nineties, SF6 was broadly used, because the “air” in race automobile tires, tennis balls and Nike Air sneakers. Refrigeration and air-con firms had been eyeing related fluorine-based chemical compounds as an environmentally pleasant different to chlorofluorocarbons (CFCs), chlorinated chemical compounds that had been destroying atmospheric ozone.
The artificial fluorine compounds had been odorless, colorless, unhazardous, nonflammable and extremely sturdy. They didn’t hurt the ozone layer, and within the case of SF6, its massive molecular measurement meant that it wouldn’t simply leak, maintaining a shoe, ball or automobile tire inflated for much longer than ambient air.
The sturdy bonds fluorine fashioned with carbon and different atoms meant the chemical compounds had been each extremely inert — they wouldn’t react with different chemical compounds — and extremely immune to degradation. The chemistry led to long-lasting refrigerants like Freon, in addition to nonstick and stain-resistant coatings like Teflon and Scotchgard. Thom Sueta, a spokesperson for The Chemours Firm, stated that one Teflon branded product, Teflon EcoElite, doesn’t include the fluorine-carbon chemistry of PFAS.
Then, in 1993, researchers with the Nationwide Oceanic and Atmospheric Administration printed a research in Science displaying simply how sturdy these compounds had been.
“They dwell ceaselessly,” stated lead creator A. R. “Ravi” Ravishankara, who known as them “immortal molecules.” Now a professor of chemistry and atmospheric science at Colorado State College, Ravishankara stated he was involved in regards to the chemical compounds’ rising use on the time and what unintended impacts they may have on the setting. He warned that if chemical compounds in use are discovered to trigger hurt, “you simply can’t take it away,” he stated.
Associated protection of ‘ceaselessly chemical compounds’
Ravishankara instantly stopped utilizing the fluorinated chemical compounds in his lab. When a consultant from Nike who had heard about his research known as to ask in regards to the chemical compounds’ security, he urged them to do the identical.
“I stated this can be a horrible factor to do,” Ravishankara stated. Nike finally phased out use of SF6 in 2006, greater than a decade later. Nike notes on its web site that it was conscious of the issue within the Nineties however that it took “years of innovation” to transition off of sulfur hexafluoride.
The largely unregulated class of artificial, fluorine-containing chemical compounds turned referred to as “the immortals” due to how lengthy they continue to be within the environment. The human-made compounds — which additionally embody tetrafluoromethane (CF4) and hexafluoroethane (C2F6) — are among the most potent and longest-lasting greenhouse gases on the planet. Tetrafluoromethane, which is a byproduct of aluminum manufacturing, is the longest-lived of all. It has an atmospheric lifetime of fifty,000 years.
The chemical compounds share the identical fluorine-based chemistry as per- and polyfluoroalkyl (PFAS) substances, the poisonous “ceaselessly chemical compounds” linked to most cancers which can be utilized in all the things from nonstick coating on pots and pans to fast-food packaging, water-repellent clothes and cosmetics.
Ranajit Sahu, an impartial environmental advisor and engineer, stated the chemical compounds had a “few a long time of nice use, after which the after-effects began to be felt.”
“First we had ozone depletion, then PFAS contamination, now local weather change, all from the identical carbon-fluorine chemistry,” Sahu stated.
International emissions of those long-lived “F” gases in 2018 equaled the local weather influence of 264 million tons of carbon dioxide, based mostly on an Inside Local weather Information evaluation of the European Union’s Emissions Database for International Atmospheric Analysis.
The determine is roughly half of 1% of all greenhouse gasoline emissions worldwide, far smaller than yearly emissions of carbon dioxide, the first driver of local weather change. Nonetheless, the emissions are nonetheless vital, equal to the greenhouse gasoline emissions of placing an additional 57 million vehicles on the street every year, in accordance the EPA’s greenhouse gasoline equivalency calculator — and driving these vehicles for hundreds of years.
Low-cost strategies may rapidly deliver emissions of the fluorinated local weather pollution to close zero and, in some instances, may even save the businesses cash.
“Technically possible substitutes exist for each single one in every of these F gases,” Benjamin Sovacool, director of the Institute for International Sustainability at Boston College.
“They’re man-made. You may make different ones.”
When planet-saving strikes are money-saving too
Electrical utilities that take part or have participated within the EPA program characterize practically half of the U.S. electrical grid. These members have lowered their annual unintended emissions of sulfur hexafluoride from 13% of the whole SF6 they utilized in 1999 to only 1% in 2020, based on the EPA’s most up-to-date stock of greenhouse gasoline emissions.
Lowering the quantity of gasoline that leaks when employees refill or drain SF6 tanks on electrical gear makes financial sense. Massive utilities use tons of of hundreds of kilos of SF6 throughout their service areas. At roughly $15 a pound, the price of having to exchange even a small proportion of misplaced gasoline every year provides up.
This was the case with California utility Pacific Fuel and Electrical Firm, which diminished its SF6 leak fee from 8% to 4% over a three-year interval ending in 2002. The corporate spent $100,000 implementing new insurance policies to cut back emissions and saved $400,000 in prevented gasoline purchases for a internet financial savings of $300,000, based on a case research printed by the EPA in 2006.
Equally, the Southern Firm, which supplies energy throughout the Southeast and is among the nation’s largest utilities, diminished its SF6 emissions fee from 10.4% in 1999 to 2.9% in 2006, the company reported in 2007. The lower in emissions saved the corporate $130,000 in 2006 and lowered prices related to outages and upkeep based on the EPA.
Brooks, the Duke Power spokesperson, stated SF6 represents a small a part of its complete emissions, however they’re taking steps to cut back leaks.
“It accounts for about three-tenths of 1% of our complete greenhouse gasoline stock,” Brooks stated. “From an effectiveness standpoint, clearly addressing our direct supply [carbon dioxide] emissions is a precedence for the corporate. However we’re additionally taking a look at alternatives to cut back the output of SF6 from our gear.”
Whereas the mixed emissions from Duke Power Carolinas and Duke Power Progress characterize the nation’s largest supply of SF6 emissions, the mixed utilities didn’t have the very best leak fee in 2020. That distinction went to Southwestern Public Service Firm, a small utility in Texas owned by Xcel Power.
Southwestern leaked 11.5% of the whole SF6 it saved in 2020, a fee greater than twice that of Duke Power Carolinas, based on an Inside Local weather Information evaluation of EPA information. A spokesperson for Xcel stated the excessive fee of emissions was resulting from a reporting error. An EPA spokesperson confirmed that the corporate submitted revised emissions information earlier this 12 months that the company is now assessing.
The states step in
Whereas the EPA hasn’t pursued rules, some states have. In 2010, California required utilities to cut back SF6 emissions by 1% per 12 months. The state allowed for a most emissions fee of 10% per 12 months beginning in 2011, reducing it to 1% by 2020. Now California goes additional, phasing out using SF6 for all new electrical gear by 2033.
“If it’s going to stay round for a very long time, it means it is advisable begin taking motion sooner moderately than later so that you don’t carry on persevering with to emit it and it retains piling up within the environment,” stated Mary Jane Coombs, a department chief with the California Air Assets Board, which regulates greenhouse gasoline emissions within the state, of the state’s SF6 guidelines. “Due to its time within the environment and due to its world warming potential, we knew we may do lots with a comparatively fast regulation.”
An Inside Local weather Information evaluation of EPA information suggests three California electrical utilities — Southern California Edison, PG&E and the Sacramento Municipal Utility District — exceeded the 1.0% most leak fee, with leak charges starting from 1.1 to 1.3% in 2020, the latest 12 months for which information is out there.
Dave Clegern, a spokesperson for the California Air Assets Board, stated solely one of many three utilities, PG&E, exceeded state rules, with a 1.1% emissions fee in 2020. Clegern stated state and federal strategies of calculating the leakage charges could differ barely and added that the ultimate determine for one of many utilities, Southern California Edison, remains to be being finalized and will change.
PG&E spokesperson James Noonan stated the corporate’s “precise emission fee for 2020 was inside state limits of 1 %.”
Clegern stated, “CARB has been in discussions with PG&E however disagrees with PG&E’s assertions.”
It’s unclear what, if any, repercussions PG&E will face for exceeding the emissions restrict. Clegern stated the Air Assets Board can’t touch upon any open enforcement instances.
Massachusetts carried out related guidelines for SF6, permitting Eversource and Nationwide Grid, the state’s two foremost electrical utilities, to leak as much as 3.5% of all of the SF6 they utilized in 2015 and ratcheting right down to a 1% most leak fee by 2020. Each utilities had been beneath the utmost allowable leak fee in 2020 based on the Massachusetts Division of Environmental Safety.
However even in states with out SF6 rules, utilities are decreasing their emissions excess of Duke Power.
PPL Electrical Utilities, an electrical firm in Pennsylvania, the place SF6 is just not regulated, had a leak fee of simply 0.045%, the bottom leak fee of any of the greater than 70 electrical utilities within the nation who submitted information to the EPA in 2020.
“We’re doing it due to the environmental causes, however the nice facet impact of it’s that we even have nice reliability,” stated David Quier, vice chairman of transmission and substations for PPL Electrical Utilities. It’s “good throughout.”
Quier stated his firm is utilizing information analytics to assist the corporate keep on high of leaks.
“Say you may have an SF6 breaker that information analytics reveals is trending towards failure,” Quier stated. “Failure for that breaker means a major leak. Ultimately, it’s going to should get changed. You’ll be able to change it earlier than it has the large leak or you’ll be able to change it afterwards.”
PPL and different electrical utilities at the moment are going additional, piloting SF6-free electrical gear at their substations.
Executives with Eversource — which supplies electrical energy to Massachusetts, Connecticut and New Hampshire — say they hope to have their first high-voltage SF6-free circuit breaker in service in Preston, Connecticut, in November.
“We’re one of many first, if not the primary, to use this expertise,” Paul Melzen, director of substation engineering and design for Eversource, stated of the precise sort of breaker the corporate is putting in. “We’re happy with that one as a result of we’re actually main our friends.”
Melzen stated limiting SF6 emissions is a key a part of the corporate’s objective to be carbon impartial by 2030. Eversource already has a comparatively low leak fee of 0.5%, based on firm officers. As the corporate appears to be like forward, Melzen stated the following step is to transition to SF6-free electrical gear.
The gear Eversource plans to put in this fall is a “vacuum circuit breaker,” which makes use of a vacuum house, or the absence of any gasoline, to interrupt electrical present. From a local weather perspective, vacuum breakers are a constructive different as a result of they don’t emit any greenhouse gasoline.
Nonetheless, a report launched by the EPA’s Electrical Energy Programs Partnership in 2020 famous that it could be “troublesome” to make use of related gear for even higher-voltage purposes that use probably the most SF6 gasoline. An alternate, fluorinated gasoline referred to as Novec is changing into more and more accessible for higher-voltage gear.
3M, the chemical firm that makes that gasoline, stated it reduces the carbon footprint of leaks from high-voltage gear by greater than 99% in comparison with gear utilizing SF6 and, in contrast to SF6, stays within the environment for under 30 years. Novec is nonflammable and doesn’t hurt atmospheric ozone, and 3M says the gasoline has low toxicity.
Melzen stated Eversource is now starting the allowing course of for a brand new substation in Massachusetts that he hopes will use Novec gasoline when it comes on-line later this decade. If the corporate can use Novec-based gear, the brand new substation will remove the necessity for greater than 60,000 kilos of extra SF6.
“We’re taking it very severely,” Melzen stated.
