Why Neighboring Power Grids Can’t Just Send Electricity Where It’s
- Analysis Data Centers
Marin Holt
- 0
- 6 minutes read
- Texas 2021: 4.5M+ lost power; ERCOT could import only ~6% of demand from neighbors
- California Sept 6, 2022: peak hit 52,061 MW; imports delivered 8,000 MW (12.5% of local demand)
- U.S. structure: Three independent interconnections (Eastern, Western, ERCOT) with very few ties between them
- Southern Spirit project: 320-mile TX–LA/MS line could have cut 2021 Texas losses ~15% (600,000 homes)
- Key constraint: Federal rules require providers to keep reserves for their own customers first
When a region runs short of power, the intuitive fix — borrow electricity from a neighbor — is far harder than it sounds. The U.S. operates three largely independent interconnections (Eastern, Western, and ERCOT in Texas) connected by “very few transmission lines,” and even within a single interconnection, power sharing is throttled by physical transmission limits, disaster damage, and federal rules that force each grid to protect its own customers first.
The 2021 Texas Lesson
During the February 2021 winter storm, more than 4.5 million Texans lost power, and ERCOT — deliberately isolated from the Eastern and Western grids to avoid federal regulation — could import only “about 6% of the demand” it was short. The isolation that protects ERCOT from federal oversight is the same isolation that left it unable to draw meaningful help when its own generation froze. A proposed 320-mile Southern Spirit Transmission line connecting Texas with Louisiana and Mississippi could, by the analysis, have “reduced the scale of the power losses by roughly 15%,” protecting “600,000 additional Texas homes.”
When Sharing Works
The counter-example is California on September 6, 2022, when peak demand reached 52,061 megawatts during an extreme heat wave. Imports from neighboring balancing authorities delivered 8,000 MW — 12.5% of local demand — and CAISO’s own analysis confirmed that “imported electricity from neighboring balancing authorities played a key role in maintaining system reliability.” The difference from Texas was not luck: it relied on “established sharing agreements” and “real-time, cross-regional coordination mechanisms already in place” through the Western Energy Imbalance Market.
The Three Constraints
Power sharing fails for three reasons the article makes concrete. First, physical capacity: the inter-tie lines simply are not large enough — New Orleans lost all eight of its transmission lines during Hurricane Ida in 2021. Second, reserve rules: federal standards “require transmission providers to have enough electricity available in reserve to serve their own local homes and businesses safely,” so a neighbor with its own peak cannot legally export. Third, timing: sharing agreements “must be arranged before the blackout begins,” and once protective systems start disconnecting parts of a failing grid, later incoming power cannot reach the affected areas.
Why It Matters
As data-center load and electrification push every region’s peak higher simultaneously, the assumption that a neighbor will have spare power to lend gets weaker. The fixes are slow and capital-intensive — Entergy New Orleans’s grid-hardening Phase 1 covers 63 miles at $100 million through 2026, and inter-regional lines like Southern Spirit take years to permit. The 2021 Texas and 2022 California cases bracket the outcome: regions with pre-arranged sharing agreements and adequate ties survive; isolated regions relying on a last-minute rescue do not.
Critical Perspective
Coverage that summarizes a single report or research finding should be read alongside the methodology section of the source. Two structural caveats: (1) sample size, geographic scope, and time window of the original research determine how generalizable the finding is, so a US-only utility survey does not map directly onto European or Asian grid conditions; (2) the framing decisions of the report’s authors (what they chose to measure, what they chose to omit) shape the conclusion as much as the data does. MGRID’s role is to surface the finding and the framing tradeoffs, not to endorse the conclusion.
