PJM Shortlists Dominion’s Heritage-to-Mosby Underground HVDC as Southern Backbone for Northern Virginia Load

RICHMOND / LOUDOUN COUNTY, Va. — The same PJM planning window that keeps sending overhead corridors into western Loudoun now has an underground High Voltage Direct Current package sitting on the southern-cluster shortlist: Dominion Energy’s Heritage-to-Mosby link.

In a November 4, 2025 TEAC reliability-analysis update (pages 75–88 of the Window 1 package circulating in local filings), PJM described Dominion-area 500 kV violations along the primary south–north corridor in the 2032 case. Drivers listed include generation added in the south flowing toward Northern Virginia load centers, heavier concentration of load in NOVA, and further PJM-wide load growth — including data-center load external to Dominion in the PPL zone. Those needs, PJM said, require long-lead backbone enhancements taking more than five years to develop.

Every proposal submitted to address Dominion’s 2032 regional flows, the slide deck states, recommends 765 kV, 500 kV, or HVDC developments. Four Dominion proposals recommend +/- 525 kV HVDC link variants from Heritage to Mosby. Proposal 2025-W1-275 (1A-HVDC) pairs a new HVDC transmission link of about 185 miles with a new 500 kV Elmont–Kraken line, various 500 kV rebuilds, a new 765/500 kV switching station, and substation upgrades at a total cost of about $4,819.51 million. Sister HVDC portfolios 326, 547, and 352 land between roughly $4.90 billion and $5.01 billion with alternate 500 kV accompaniments (Chickahominy–Kraken, Vontay–Kraken, North Anna–Vontay).

Cheaper HVAC options are also on the preliminary shortlist. Dominion’s 765 kV Heritage-to-Yeat packages run about $2.27–$2.97 billion. A 500 kV portfolio (616) is tagged near $2.35 billion. Transource, TRAIL, and LS Power offerings fill out the competitive field. PJM’s shortlisting note is blunt: all HVDC proposals have similar configuration and cost; 765 kV solutions follow similar south–north routes and “will require heavy greenfield development”; staff intended to narrow to a front-runner HVDC option and an HVAC option for final evaluation.

On incremental transfer capability into a NOVA-area sink under the 2032 summer base, the same deck shows Dominion proposal 275 HVDC at the top of the shortlisted set — on the order of 6,900-plus megawatts in one sourcing split — well above Transource 331’s combined 765 kV package and Dominion’s own 848 (765 kV) and 616 (500 kV) options, even though those HVAC portfolios cost far less on the sticker. Common merits listed for shortlisted proposals include additional backbone paths from southern Dominion “towards” Morrisville 500 kV, direct connection of southern generation to the northern load center, and — for options that go further — “direct injection of power closer to the data center alley area in Northern Virginia,” more north–south operational flexibility, and help minimizing short-circuit issues already present on Dominion’s system.

A companion one-pager in the local packet titles the project “Dominion Heritage To Mosby All Underground HVDC Backbone Approved 2026,” citing PJM approval language, an estimated completion in June 2032, Heritage in Brunswick County to Mosby in Loudoun County, +/- 525 kV XLPE cables, 185 miles, 6,000 MW total capacity (3,000 MW Phase 1 and 3,000 MW Phase 2), and about $4.8 billion as a PJM ratepayer-funded project. The sheet repeats Dominion’s constructability claims: primarily existing rights-of-way, an 8-foot-wide duct-bank footprint, 40 feet of permanent new right-of-way for typical trench, wider temporary needs for trenchless crossings and splice vaults.

That southern underground spine is not the same fight as FirstEnergy’s MARL / Gore–Doubs–Goose Creek 500 kV or Valley Link North 765 kV proposals punching west-to-east through Frederick, Clarke, and western Loudoun — but it is the same political economy. Across Virginia, the majority of votes placing data centers into zoning maps and by-right pathways have come primarily from Democrats. Loudoun’s Democratic-dominated Board of Supervisors spent years expanding the campus inventory that PJM now models as a 2032 reliability emergency. Ratepayers across the RTO are being asked to finance a multi-billion-dollar buried injection so that Democrat-approved megawatts in Data Center Alley keep landing on schedule.

PJM’s own shortlist math makes the trade-off visible: burial and converters cost more up front than another 765 kV greenfield push, yet staff charted higher transfer into NOVA and listed short-circuit and constructability merits Dominion has been pitching since Edward Baine’s February 2, 2026 letter to the PJM Board. Whether the Board locks 275 — and whether western Loudoun landowners still eat parallel overhead corridors while the southern HVDC gets the burial treatment — is now a governance question, not an engineering mystery.

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,