Grid's Decade-Long Bottleneck

The math is unforgiving. Meeting stated decarbonization goals requires 47,000 to 57,000 miles of new high-voltage transmission by 2035. Current construction rates deliver roughly 1,500 miles per year. At that pace, the country will have built one-third of required capacity when the deadline arrives. Solar panels and wind turbines can be manufactured and installed in months. The wires to deliver their output take a decade from conception to completion.

This mismatch explains why over 2,000 GW of generation—mostly solar and storage—sits in [interconnection queues](https://www.canarymedia.com/articles/transmission/chart-the-us-clean-energy-backlog-is-getting-bigger-and-bigger), waiting years for grid access that may never come. It explains why CAISO curtailed $84 million worth of solar generation in 2024 alone, and why PJM's congestion costs exceed $2 billion annually. Transmission is the invisible constraint binding the entire clean energy transition.

Where Physics Meets Politics

The most severe constraints separate renewable resource areas from the people who need the power.

West Texas wind and solar generation exceeds local demand by factors of five or more. The CREZ lines completed in 2013—the last major transmission buildout in ERCOT—have reached capacity. Export pathways to Dallas-Fort Worth and Houston now limit how much new generation can connect, stranding projects that could otherwise displace gas-fired imports.

California's solar belt in the Inland Empire generates more than local circuits can export. Transmission to coastal load centers constrains output during peak solar hours, forcing curtailment of generation that ratepayers have already contracted to purchase. The Midwest wind corridor from North Dakota through Kansas produces more than SPP's grid can absorb; congestion patterns reveal power that cannot flow east to load centers willing to buy it.

Offshore wind projects in the Northeast face landing point constraints before a single turbine spins. Existing onshore infrastructure cannot accommodate projected additions without reinforcement that nobody has permitted, financed, or begun constructing.

The Grain Belt Express illustrates the timeline problem. This 800-mile HVDC line would deliver 5,000 MW of Kansas wind to Indiana and Illinois—enough capacity to power millions of homes with zero-marginal-cost generation. The project began permitting in 2014. Missouri rejected the application twice before eventual approval. Construction now targets 2029 commercial operation. Fifteen years from conception to energization represents a typical timeline for major transmission projects. The wind turbines such lines would connect can be built in eighteen months.

The Transmission Construction Gap

The Transmission Construction Gap. At 1,500 miles/year, the US will build only one-third of the transmission needed by 2035.

FERC's Planning Overhaul

Order 1920, issued in May 2024, represents FERC's most ambitious transmission reform in over a decade. The rule requires transmission providers to develop long-term regional plans with at least a 20-year planning horizon—a sharp departure from the three-to-five year windows that previously dominated utility forecasting.

The order's core innovation lies in mandatory scenario planning. Transmission providers must evaluate future grid needs across multiple plausible futures incorporating load growth, generation shifts, and extreme weather—what FERC terms "Long-Term Scenarios." According to the Commission's explainer, this approach aims to identify transmission needs driven by changes in the resource mix, demand patterns, and the increasing frequency of severe weather events.

For cost allocation—historically the kill zone for regional projects—Order 1920 requires transmission providers to develop methods that satisfy six specified benefits, including reduced loss-of-load probability and production cost savings. The rule also introduces a state agreement process, allowing state regulators to voluntarily agree on alternative cost allocation for projects selected through long-term planning.

Order 1920-A, issued in response to rehearing requests, expanded state involvement further. The April 2025 clarification gave state regulators additional opportunities to participate in both planning and cost allocation decisions—a response to concerns that the original rule sidelined state commissions.

What the Order Cannot Fix

Order 1920 addresses planning but not permitting—and permitting is where projects die.

A new transmission line must obtain approval from FERC for rates, the Bureau of Land Management and Forest Service for federal lands, state utility commissions in each state crossed, county and municipal authorities along the route, and tribal nations whose lands may be affected. Each jurisdiction operates on its own timeline with its own priorities. Opposition at any level can halt a project indefinitely.

The Cost of Congestion

The Cost of Congestion. Transmission constraints force ratepayers to pay billions in congestion costs and waste contracted generation.

The Inflation Reduction Act expanded federal backstop authority. In designated National Interest Electric Transmission Corridors, FERC can theoretically issue permits over state objections. DOE designated three such corridors in 2024—Mid-Atlantic, Midwest, and Southwest. But this authority remains untested in court, and political opposition to federal override of state siting decisions crosses party lines in ways that make its durability uncertain.

The cost allocation reforms in Order 1920 also face structural limits. Interregional projects—lines crossing RTO boundaries—still require agreement between grid operators with misaligned incentives. The MISO-SPP seam illustrates the problem: both RTOs have identified the same transmission needs in planning studies for years. Neither has agreed on cost sharing. Projects that would benefit ratepayers in both regions remain unbuilt while congestion costs mount.

Models That Work—And Why They're Hard to Replicate

Texas provides a successful template within its constraints. The 2005 CREZ legislation designated renewable energy zones and allocated transmission costs across all ratepayers. The approach produced 18,500 MW of transmission capacity between 2008 and 2013—the kind of buildout the rest of the country has failed to replicate.

The CREZ model worked because ERCOT operates within a single state. Federal jurisdiction and interstate cost allocation disputes did not apply. The political economy was simpler: Texas legislators could weigh statewide benefits against statewide costs without neighboring states demanding compensation or objecting to route selection.

Germany implemented a similar zone-based approach for offshore wind, with federal permitting overriding state-level objections. Construction timelines dropped from fifteen years to eight. India designated Renewable Energy Corridors connecting solar parks in Rajasthan and Gujarat to industrial load centers, with the Central Transmission Utility building infrastructure ahead of generation—shifting timing risk from developers to the state.

These models share a common feature: centralized authority that can override local objections and socialize costs across beneficiaries. The US system fragments that authority across federal agencies, fifty state commissions, and hundreds of local jurisdictions—each with veto power, none with accountability for the cumulative delay.

Grain Belt Express Timeline

Grain Belt Express Timeline. A single 800-mile HVDC line: 15 years from conception to energization, while wind turbines take 18 months.

The Stakes for Stakeholders

For utilities, Order 1920 creates planning obligations with material cost implications. Long-term scenario analysis requires analytical capabilities many transmission providers lack. Compliance filings are due according to schedules FERC established in June 2025 guidance, and the quality of those filings will shape regional transmission portfolios for decades.

For renewable developers, the order offers a potential pathway out of interconnection purgatory—but only if regional plans actually identify and advance the projects that queue backlogs reveal are needed. Planning is not permitting, and permitting is not construction. The gap between transmission identified in studies and transmission energized on the grid remains the binding constraint.

For state regulators, Order 1920-A's expanded participation rights come with expanded responsibility. States that engage constructively in the planning process gain influence over cost allocation. States that abstain may find costs allocated by FERC-approved default methodologies they had no role in shaping.

For investors, the order reduces one category of risk—arbitrary planning decisions—while leaving permitting and litigation risk unaddressed. Transmission projects still require patience beyond typical private equity horizons. Infrastructure funds with fifteen-year duration capital remain better positioned than sponsors seeking five-year exits.

What to Watch

FERC's compliance filing schedule, established in June 2025, sets the near-term milestones. The quality and ambition of regional transmission plans will become visible over the next twelve to eighteen months. Watch for whether RTOs interpret the long-term planning requirements as floor or ceiling—minimum compliance or genuine infrastructure investment.

Congressional permitting reform discussions continue, with bipartisan acknowledgment that planning alone cannot accelerate construction. Whether legislative action materializes before the 2026 elections remains uncertain; transmission permitting lacks the political salience to drive compromise absent a catalyzing crisis.

The ultimate test is physical: miles of conductor strung, substations energized, congestion costs reduced. By that measure, Order 1920's success will not be measurable until the early 2030s at best. The generation waiting in interconnection queues cannot afford to wait that long—and neither can the ratepayers paying billions annually for the power that congested transmission cannot deliver.