US transmission inches forward in 2026 as HVDC corridors advance and the gap stays open

Summary

US Transmission is advancing unevenly in 2026. The Champlain Hudson Power Express, carrying Canadian hydropower into New York, is set to begin delivery this year, and New England Clean Energy Connect is flowing. Merchant HVDC corridors progress: Cimarron Link (400 miles, 1,900MW, Oklahoma) and Southern Spirit (320 miles, 3,000MW bidirectional, linking ERCOT to the Southeast). MISO is pushing a 765kV north-south backbone; SPP studies multi-state HVDC; PJM/NYISO explore offshore-wind HVDC meshes. But planners warn the buildout still lags load growth and queued renewables without permitting and interregional reform, DOE cancelled Grain Belt Express loan guarantees in 2025, though developers say it continues.

By the numbers

• 1,900 MW, Cimarron Link firm capacity (400 miles, Oklahoma).
• 3,000 MW, Southern Spirit bidirectional capacity (320 miles, ERCOT-Southeast).
• 765 kV, AC backbone voltage MISO is advancing north-to-south.
• 3, US interconnections HVDC ties aim to stitch together.
• 2026, Champlain Hudson Power Express expected delivery start.

Why it matters

Transmission is the binding constraint on both connecting cheap renewables and serving data-center load; congestion drives curtailment, negative prices and reliability risk. Lines take a decade, demand is arriving now, the mismatch is the core of US grid stress.

What to watch

• Champlain Hudson and Cimarron Link in-service milestones.
• Federal permitting/interregional-planning legislation.
• Whether offshore-wind HVDC meshes survive policy and cost pressure.