Williams has filed with FERC for authorization to build its Southeast Supply Enhancement Project that would add about 1.6 Bcf/d of capacity to its Transcontinental Gas Pipe Line Co. (Transco) for natural gas deliveries from Virginia to Georgia.
The pre-filing request with the Federal Energy Regulatory Commission on Feb. 1 comes three months after Williams said customer interest was strong enough to attract 20-year agreements of more than 1.4 Bcf/d for firm capacity.
At an official capacity of 1,586,900 Dth/d, the project is now roughly double the original offered amount of 800 MMcf/d in an open season last summer.
The brownfield project would expand Transco’s existing 2.5 Bcf/d of southbound capacity from Station 165 in south central Virginia, with a targeted in-service date of November 2027. The stretch of pipeline is heavily constrained in meeting growing gas demand in the Mid-Atlantic and Southeast, Williams said in its filing.
As an indication of the chokepoints, NGI’s Transco Zone 5 cash prices soared to an average $24.060/MMBtu during the peak of last month’s winter storms. That was higher than many hubs in the capacity-constrained Northeast, where New England’s PNGTS rose as high as $16.635.
The bottleneck is set to become even worse when the 303-mile Mountain Valley Pipeline LLC (MVP) enters service, expected this year, bringing as much as 2 Bcf/d of Marcellus and Utica shale production to an interconnect with Transco near Station 165. From this area, Transco can move gas in three directions: 2.5 Bcf/d to both the north and south and about 700 MMcf/d eastward on the Virginia lateral, Williams CEO Alan Armstrong said on an earnings call in November.
“There's a lot of demand for that capacity, and so it's not like it's just sitting there available for somebody to come in and buy,” Armstrong said. The project uses existing right-of-way that “provide the least points of resistance from a permitting standpoint,” he said.
Specifically, the project would build about 55 miles of looping within the Transco corridor in Virginia and North Carolina, add compression capacity in Virginia, the Carolinas, Georgia and Alabama and make other modifications to pipes and facilities, according to the filing.
Transco said it anticipated that construction would begin in the first quarter of 2026.
Demand Multiplies
Southbound capacity on Transco through its Station 160 was constrained “every day” for non-primary nominations in data between January 2021 and January 2024, according to the filing. On 85% of days, flows were limited to nominations for primary firm service and the highest tier for non-primary service, it said.
“By increasing primary firm pipeline capacity in Zone 5, the project will provide shippers with firm access to competitive gas supplies and support overall reliability and diversification of energy infrastructure in the Mid-Atlantic and southeast portion of the United States,” Williams said in the filing.
Duke Energy Carolinas is the biggest subscriber to the project with 1 million Dth/d contracted, followed by Southern Companies Services with 400,000 Dth/d, according to the resource report filing to FERC.
Southern Cos. subsidiary Georgia Power plans to build three new dual fuel generators with a combined 1,400 MW of capacity when fired by gas, Williams said. Georgia Power anticipates 6,600 MW in load growth through the 2030-2031 winter, “an approximately 17x multiple of its previous forecast of 400 MW,” the filing states.
Additional Projects
Transco and the Equitrans-led MVP project are also pursuing other capacity expansions in the Southeast.
MVP has scaled back the proposed Southgate extension of its mainline into North Carolina, four years after the project was approved by FERC. The revamped project, with 550,000 Dth/d of firm transport commitments, would run 31 miles instead of 75 miles from the mainline terminus to Rockingham County, NC, according to MVP.
Transco is also developing the Southside Reliability Enhancement Project that would add 423,400 Dth/d of capacity from south of Transco’s interconnect with MVP east into North Carolina by late 2024. FERC OK’d it in July.
Transco’s proposed Commonwealth Energy Connector greenlit by FERC in November would add 105,000 Dth/d near Station 168 in Virginia by end of 2025.
