The 1,413-MW Mystic Generating Station, a longtime workhorse for New England, shut its doors for good May 31. Located in Charlestown, MA, on the north side of Boston, Mystic is adjacent to the Everett LNG terminal, which supplied 100% of Mystic’s natural gas for several decades. The power plant’s closure meant the Everett terminal might also be history. However, the Massachusetts Department of Public Utilities (DPU) recently approved new contracts that will keep Everett LNG open for at least six more years. In today’s RBN blog, we’ll discuss the combined impact of Mystic’s demise and Everett’s stay of execution, how the region has handled this summer’s heat wave, and what could be in store for next winter.
The Everett LNG import terminal and the Mystic Generating Station are linked by more than proximity. Constellation Energy, which owns both facilities, initially planned to close ’em both. Mystic was the largest, most strategically located gas-fired plant in the six-state region, whose electric grid is overseen by ISO New England (ISO-NE), the regional transmission organization (RTO). In 2018, Mystic’s then-owner, Exelon Corp., filed its intention with ISO-NE to retire the plant by June 1, 2022, stating it could no longer operate it and turn a profit. ISO-NE, in turn, said the units at Mystic were essential for fuel and system reliability in the Greater Boston area and required the plant to remain open through May 31, 2024.
In recent years, Mystic has served largely as a backup power generator during periods of extreme heat or cold when electricity is in high demand. (Mystic was built in the 1940s and was one of the oldest gas-fired power plants in the U.S., leading to inefficiency, increased operational costs and lower dispatch rates. An analysis by ISO-NE in 2023 showed that electricity customers in the region paid $536 million over 2022-23 to keep the station operational.) The gray-shaded area in Figure 1 below shows the range of its monthly output in gigawatt-hours (GWh) in the 2018-22 period (when it generally operated at about 20% of its rate capacity), while the blue line shows its minimal output through most of 2023 (averaging less than 10% of its rated capacity) and the black line its modest output in the first three months of 2024. Executives at Constellation held steady on their wishes to close the plant, maintaining that it was no longer cost effective. Still, Mystic had the potential to generate enough power for nearly 1.5 million homes if and when that power was needed.
Figure 1. Mystic Generating Station Monthly Generation. Source: EIA
The nearby Everett terminal, which has 3.4 Bcf of LNG storage capacity, has played a crucial role in stabilizing gas supplies in New England — it can supply up to 35% of regional gas demand on peak winter days — and is typically used to fill supply gaps during high-demand periods or when regional gas systems are under significant stress. Located in Boston Harbor, it is the oldest such facility in the U.S. — it came online in 1971 — and is one of three LNG import terminals in New England. However, the terminal’s import volumes have been declining for nearly 20 years.
(We should note that one of the prime difficulties in attracting spot LNG cargoes is that the Jones Act essentially requires imported LNG to be foreign-sourced, as there are no Jones Act-compliant LNG tankers and the National Defense Authorization Act for both 2021 and 2023 severely restricted the use of waivers, among other restrictions. We talked about the importance of LNG imports in stemming severe weather impacts in The Last Resort. Another big challenge is timing, as spot cargoes would need to be scheduled in advance of when they would be needed, which is tricky and risky.)
Figure 2. Everett LNG Import Terminal, Mystic Generating Station, and Key Regional Pipelines.
Source: RBN
The fate of the Everett terminal (red diamond in Figure 2 above) is complicated because it’s one of the only facilities on the East Coast that can accept LNG from giant tankers and re-gasify it for local use. (The other two import terminals in New England are the Northeast Gateway and Neptune facilities near Boston. Only Northeast Gateway is active, as operations at Neptune were suspended until June 2025 due to poor market conditions.) In addition to the Mystic Generating Station (yellow triangle), the terminal is also connected to the Tennessee Gas Pipeline (lavender line) and Algonquin Gas Transmission (green line) systems — the primary conduits for gas piped in from the Marcellus/Utica — which together feed about 12,000 MW of gas-fired power and provide gas for heating, cooking and other residential and commercial purposes.
While ISO-NE determined that New England could manage without Mystic, the potential closure of the Everett facility caused concern about gas-supply availability around Boston — particularly during the winter, when pipeline constraints can limit deliveries into the region. During moderate winter weather, the ISO had projected Everett’s closure would result in an energy shortfall of 10,000-20,000 megawatt-hours (MWh) distributed over four days. With total demand at about 400,000 MWh on a cold day, that translated to a power shortage of 0.6% to 1.2%, which could be fully mitigated by increased use of diesel for power generation. But ISO-NE said that If Everett were to remain operational, no shortage would be expected. During a severe winter, the daily shortfalls without Everett were expected to grow to 30,000-67,000 MWh distributed over nine to 13 days, with power shortages of up to 1.8%, which could be only partially mitigated by expanded diesel inventory, raising reliability risks for the region. But just like in the moderate scenario, no shortage was forecast if Everett remained operational, underlying its role in maintaining reliability.
With that in mind, the Massachusetts DPU approved new long-term contracts in May with three New England utilities — National Grid, Eversource and Unitil — to supply natural gas from June 2024 to March 2030. The agreements provide each company with seasonal (November-to-March) natural gas supply through the Everett LNG terminal and allow Constellation to keep it open through the winter of 2029-30.
The Mystic shutdown is not expected to cause any regional power disruptions. Transmission upgrades have brought more electricity into the Boston area in recent years and the region has also bolstered its solar resources, lessening the need for Mystic as a backup power source. New England had about 80 MW of solar generating capacity in 2010; that had grown to 7,300 MW by the end of 2023. The installations, representing a variety of sizes and locations, produced an estimated 8,000 GWh in 2023. That growth is expected to continue over the next decade, as ISO-NE anticipates that in 2033 about 13,500 MW of distributed solar capacity will produce about 16,900 GWh of electricity.
Figure 3. Electricity Demand and Peak Temperatures on June 20. Source: ISO-NE
While New England will have to wait a few months for its first winter test after Mystic’s closure, its first summer heat wave began June 16 and lasted about a week, with temperatures in the 90s — about 14 degrees above normal. Electricity demand in New England peaked at 23,324 MW on June 20 (tallest red bar in Figure 3), approaching 2023’s hourly peak. Solar generation reached as high as 5,106 MW on June 20, and ISO-NE said overall demand would have been higher without the region’s expanded behind-the-meter (BTM) solar generation resources.
The ISO also said the power grid remained reliable during the heat wave, although it did declare a “Power Caution” on June 18 after unexpected generation outages caused its operating reserve to dip. During the heat wave utilities in New England predictably burned more natural gas to meet demand, with power burn reaching 1.7 Bcf/d on June 19, according to RBN data, well above the five-year average of about 1.2 Bcf/d for that time of year. For the week, power burn in the region averaged 1.4 Bcf/d, up 40% from the previous week and the month-to-date average. Sendout from the Everett LNG terminal was minimal and unchanged from usual levels that week, indicating that power generators in the region didn’t need to call on it for additional supplies. (For more on the region’s gas market, see our weekly NATGAS Appalachia report.)
Still, winter cold snaps and storms can be more problematic than summer heat waves in the Northeast, given the pipeline constraints in the region and diminished potential for solar generation. But with the Everett terminal remaining open for the next six years and the region’s beefed-up solar capacity, the hope is that New England could face an extended period of bitter cold temperatures and still provide the necessary heat and power — even with Mystic going bye-bye.
Part 1 of our two-part webcast series, “From Ground Up: Building A Comprehensive Understanding of Natural Gas Pipelines,” is at 2:30 pm CT Tuesday, August 13. Rick Smead, Managing Director of RBN Energy Advisory Services, will be presenting a detailed look at natural gas pipelines, their history, regulation and how new projects are handled. The focus is heavily on federally regulated interstate pipelines, with some coverage of intrastate pipelines as well. The event is exclusively for Backstage Pass subscribers. For more information and to register, click here.
“Hello, Goodbye” was written by Paul McCartney and credited to Lennon/McCartney. It was recorded at EMI (Abbey Road) Studios in London in October-November 1967, with George Martin producing. The song was released as a single in November 1967, backed with John Lennon’s “I Am the Walrus” (also credited to Lennon/McCartney). It was the first non-album single released by the group since the death of their manager, Brian Epstein, and since the release of the phenomenally successful Sgt. Pepper’s Lonely Hearts Club Band album. Promotional films were made for “Hello, Goodbye” featuring The Beatles lip-syncing to the song, wearing their Sgt. Pepper’s uniforms. One of the “Hello, Goodbye” promotional films aired on The Ed Sullivan Show in the U.S. in 1967. The song went to #1 on the U.S. Billboard Hot 100 and has been certified Gold by the Recording Industry Association of America (RIAA). Both “Hello, Goodbye” and “I Am The Walrus” were included on the U.S. Magical Mystery Tour album, released in November 1967. Personnel on the record were: Paul McCartney (lead, backing vocals, bass, piano, bongos, conga), John Lennon (backing vocals, guitar, Hammond organ), George Harrison (backing vocals, lead guitar), Ringo Starr (drums, maracas, tambourine, backing vocals on coda), and Kenneth Essex and Leo Birnbaum (viola).
The Beatles were an English rock band formed in Liverpool in 1960. With the lineup of John Lennon, Paul McCartney, George Harrison and Ringo Starr, the group is the best-selling music act in history, with sales of over 800 million records worldwide. They have released 23 studio albums, five live albums, 53 compilation albums, 21 EPs and 63 singles. The band also released four full-length motion pictures. The group has won one Academy Award, one Billboard Award, four Brit Awards, 26 Grammy Awards, 15 Ivor Novello Awards, one MTV Video Music Award, and three World Music Awards. They are members of the Rock and Roll Hall of Fame, the UK Music Hall of Fame, and the Vocal Group Hall of Fame. They were awarded MBE's by the Queen in 1965. The Beatles have six Diamond albums, 20 multi-Platinum albums, 16 Platinum albums and six Gold Albums, as certified by the RIAA. The Beatles officially broke up in 1970. John Lennon was murdered in 1980. George Harrison passed away in 2001. Paul McCartney and Ringo Starr still record and perform as solo artists.
