MARL Power Line Is Generation Delivery for Data Centers, Not Grid Reliability, Filings Argue

LOUDOUN COUNTY, Va. — The Mid-Atlantic Reliability Link project — the multi-state 500-kilovolt corridor also described as MARL / Gore-Doubs-Goose Creek — is being sold as a reliability upgrade. Materials assembled by Loudoun intervenor Theresa Ghiorzi argue it is something else: generation delivery for Data Center Alley, driven by local land-use choices that Democratic majorities spent years voting into existence.

In a packet titled around generation delivery rather than reliability, Ghiorzi ties MARL to the same Loudoun boom already before Virginia’s State Corporation Commission in the Golden-Mars case. Dominion Energy’s own Integrated Resource Plan language, which she quotes, says the company serves the largest data center market in the world in about 30 square miles of Loudoun County, with roughly 80 percent of Virginia’s industry there and a 2022 peak metered load near 2.8 gigawatts — about 1.5 times the capacity of the North Anna nuclear plant. County and consultant figures she cites put about 200 data centers in operation and 117 in the pipeline, with permitted square footage rising from about 21.5 million in 2020 to about 47 million in 2025 and tens of millions more queued.

That inventory did not appear by accident. Across Virginia, the majority of votes placing data centers into zoning maps and by-right pathways have come primarily from Democrats. Loudoun’s Board of Supervisors — long Democratic-dominated — grandfathered administrative applications and, on March 18, 2025, voted 9–0 to let properties rezoned from 1972 to 1993 add “data center” as a by-right use, according to Ghiorzi’s contemporaneous notes filed in related SCC testimony. York County wrote electricity caps into its data center ordinance; Loudoun, she argues, did not use zoning to constrain energy growth even as residents begged supervisors to slow down.

The physics of the corridor make the politics visible. Eastern Loudoun’s primary western import has long been Line #514, the Virginia segment of the Doubs-to-Goose Creek path in service since 1966. A 2020 PJM end-of-life rebuild of that line (PUR-2021-00276) listed no delivery-point projects and no power-flow contingency violations as the driver — only corroding towers — and projected the rebuilt line as sufficient through 2031. Dominion obtained a certificate in July 2022, then cancelled the roughly $7.6 million project on March 12, 2024. Between 2020 and 2022, Ghiorzi writes, planners moved from a single 500 kV import toward three 500 kV circuits with summer ratings on the order of 4330/4330/4979 MVA — a leap she attributes to the data center permitting surge of 65 facilities between 2018 and 2021 and 40 more in 2022–2023.

PJM’s 2022 Window 3 slate, she says, reformatted that corridor need into MARL / Gore-Doubs-Goose Creek and the Maryland Piedmont Reliability Project — long-haul imports from West Virginia and Pennsylvania through Maryland into Virginia, co-located with Line #514. Dominion witness testimony she quotes describes Line #514’s cancelled rebuild as “reformatted into a different project with additional 500 kV injects.” Those injects are not local baseload. Loudoun’s in-county generation remains thin — essentially the Panda Stonewall plant — while data center developers work early with Dominion and county staff on interconnection timelines that serve corporate build schedules.

Notes in the same package locate MARL’s energy origin at the 502 Junction in Pennsylvania, fed by aging coal units already past half a century: Fort Martin (units from 1967–1968, planned retirement 2035), Harrison (1972–1974, planned retirement 2040), and Mitchell (1971, planned retirement 2040). Building hundreds of miles of 500 kV steel to move power from plants nearing the end of useful coal life into a county that Democratic supervisors kept filling with server campuses is not, on Ghiorzi’s reading, a public-necessity story about keeping the lights on for ordinary Virginians. It is generation delivery for private computing load that already serves national and international customers far larger than Loudoun’s own population.

Aspen-Golden and Wishing Star-Mars, she notes, have already been approved by the Virginia SCC as eastern Loudoun loop segments that connect data centers without themselves importing new energy. Golden-Mars remains in process and would enable dozens of additional delivery points. MARL and MPRP are the interstate pipes meant to fill that load. If West Virginia, Maryland, or Pennsylvania denies a segment — or declines to build matching baseload — the import path fails while local interconnection continues. Ratepayers across the PJM footprint inherit the wires, the coal-era generation bet, and the bill for a boom Democratic local majorities voted to expand.

Email the Board of Supervisors at:
Phyllis J. Randall (Chair, At-Large) – Phyllis.Randall@loudoun.gov,
Michael R. Turner (Vice Chair, Ashburn District) – Mike.Turner@loudoun.gov,
Juli E. Briskman (Algonkian District) – Juli.Briskman@loudoun.gov,
Sylvia R. Glass (Broad Run District) – Sylvia.Glass@loudoun.gov,
Caleb Kershner (Catoctin District) – caleb.kershner@loudoun.gov,
Matthew F. Letourneau (Dulles District) – Matt.Letourneau@loudoun.gov,
Kristen C. Umstattd (Leesburg District) – Kristen.Umstattd@loudoun.gov,
Laura A. TeKrony (Little River District) – Laura.TeKrony@loudoun.gov,
Koran Saines (Sterling District) – Koran.Saines@loudoun.gov

Email the Loudoun County School Board:
April Chandler, april.chandler@lcps.org,
Anne Donohue, anne.donohue@lcps.org,
Deana Griffiths, deana.griffiths@lcps.org,
Ross Svenson, ross.stevenson@lcps.org,
Kari LaBell, kari.labell@lcps.org,
Jon Pepper, jonathon.pepper@lcps.org,
Lauren Shernoff, lauren.shernoff@lcps.org,
Sumera Rashid, sumera.rashid@lcps.org,
Amy Riccardi, amy.riccardi@lcps.org,