Grid Constraints and U.S. Interconnection Queues 2026
Why grid constraints can slow the energy transition
Grid constraints occur when physical or operational limits prevent electricity generation, storage or demand from connecting to or using the power network as intended. They can appear through connection queues, transmission congestion, renewable curtailment, local hosting-capacity limits or reliability interventions.
This page uses U.S. interconnection queues as one measurable indicator of pressure on grid access. The ranking compares 20 states by requested generation and storage capacity in current interconnection queues. A larger queue ranks higher, but a larger queue does not by itself mean that a state has worse congestion, weaker reliability or a larger transmission deficit.
The table is a compiled research dataset based on 3 sources, with row-level source and method notes shown in the ranking table. The 20 ranking values themselves come only from GridAlmanac; Lawrence Berkeley National Laboratory provides the underlying Queued Up 2026 dataset and methodology, while the International Energy Agency provides broader grid-system context. The LBNL backbone covers data through December 31, 2025; GridAlmanac reports ISO-region status refreshes through July 2026 where applicable. Data were checked September 7, 2026.
Metric: requested generation and storage interconnection capacity. Unit: GW. Direction: higher requested capacity ranks higher. Coverage: 20 confirmed states from a national source covering 48 states. The source dataset includes multiple technologies, including solar, storage, wind and gas projects; this is not a renewable-only ranking.
Data status: 20 industry_observed_value rows; 0 official_value; 0 calculated_value; 0 official_forecast; 0 modeled_projection.
Texas has the largest requested-capacity total among the confirmed state values.
New York is No. 20; Minnesota is first outside the ranking at 24.56 GW.
Calculated from the 20 observed state values shown in the main ranking.
GridAlmanac national total using its primary-component requested-capacity definition.
GridAlmanac national source coverage; the 20 largest confirmed state totals are displayed here.
GW · industry_observed_value · GridAlmanac 2026 snapshot · LBNL backbone through Dec 2025.
Grid constraints are broader than interconnection queues
An interconnection queue is a pipeline of proposed generation or storage projects requesting permission to connect to the grid. Queue capacity measures requested access to the network. It is not the same as installed capacity, future capacity or a direct engineering measure of transmission congestion.
Grid constraint: a physical or operational limit that restricts the ability to connect, transport, dispatch or balance electricity. Interconnection queues are one observable symptom of that wider system problem.
Four common ways grid constraints appear in data
| Indicator family | What it captures | Main interpretation limit |
|---|---|---|
| Interconnection queues | Projects waiting for studies, agreements or network upgrades before connection. | Queue size includes proposals that may later withdraw and does not directly measure congestion. |
| Congestion and redispatch | Transfer limits that restrict how electricity can move across the network. | Results depend on network geography, market design and measurement method. |
| Curtailment | Available generation that is reduced because the system cannot absorb or transport it under prevailing conditions. | Curtailment can reflect transmission limits, balancing needs, local constraints or market conditions. |
| Reliability stress | Outages, reserve stress or emergency operating actions. | Reliability outcomes have many causes and should not automatically be attributed to transmission constraints or renewable deployment. |
Why interconnection queues matter
Lawrence Berkeley National Laboratory reports that more than 2,060 GW of generation and storage capacity were actively seeking U.S. grid interconnection at the end of 2025. For projects reaching commercial operation in regions with available timing data, the median period from interconnection request to commercial operation exceeded five years in 2025.
Queue volume is not a construction forecast. Of capacity submitting interconnection requests from 2000 through 2020, 13% had reached commercial operation by the end of 2025, while 75% had withdrawn and 10% remained active.
Top 10 U.S. states by requested interconnection queue capacity
Texas has the largest state queue in this snapshot at 503.59 GW. California ranks second at 122.29 GW, followed by Arizona at 89.87 GW. The ranking shows where requested grid access is concentrated; it does not rank states by transmission reliability or physical congestion severity.
Top 10 confirmed states by requested generation and storage interconnection capacity
| Rank | State | Requested capacity | Source / Method Note |
|---|---|---|---|
| 1 | Texas | 503.59 GW | industry_observed_value; GridAlmanac 2026 snapshot; 2,080 projects; ISO statuses through Jul 2026 where applicable; LBNL backbone through Dec 2025. |
| 2 | California | 122.29 GW | industry_observed_value; GridAlmanac 2026 snapshot; 413 projects; ISO statuses through Jul 2026 where applicable; LBNL backbone through Dec 2025. |
| 3 | Arizona | 89.87 GW | industry_observed_value; GridAlmanac 2026 snapshot; 278 projects; ISO statuses through Jul 2026 where applicable; LBNL backbone through Dec 2025. |
| 4 | Oregon | 85.85 GW | industry_observed_value; GridAlmanac 2026 snapshot; 323 projects; ISO statuses through Jul 2026 where applicable; LBNL backbone through Dec 2025. |
| 5 | Nevada | 72.61 GW | industry_observed_value; GridAlmanac 2026 snapshot; 247 projects; ISO statuses through Jul 2026 where applicable; LBNL backbone through Dec 2025. |
| 6 | Illinois | 63.52 GW | industry_observed_value; GridAlmanac 2026 snapshot; 343 projects; ISO statuses through Jul 2026 where applicable; LBNL backbone through Dec 2025. |
| 7 | Michigan | 53.99 GW | industry_observed_value; GridAlmanac 2026 snapshot; 279 projects; ISO statuses through Jul 2026 where applicable; LBNL backbone through Dec 2025. |
| 8 | Indiana | 51.13 GW | industry_observed_value; GridAlmanac 2026 snapshot; 249 projects; ISO statuses through Jul 2026 where applicable; LBNL backbone through Dec 2025. |
| 9 | Georgia | 46.50 GW | industry_observed_value; GridAlmanac 2026 snapshot; 204 projects; ISO statuses through Jul 2026 where applicable; LBNL backbone through Dec 2025. |
| 10 | Oklahoma | 45.04 GW | industry_observed_value; GridAlmanac 2026 snapshot; 218 projects; ISO statuses through Jul 2026 where applicable; LBNL backbone through Dec 2025. |
Chart: Top 20 state interconnection queues
Methodology
The table is a compiled research dataset based on 3 sources, with row-level source and method notes shown in the ranking table. GridAlmanac is the controlling source for the state ranking values, Lawrence Berkeley National Laboratory provides the underlying queue dataset and methodology, and the International Energy Agency provides broader grid-system context.
Ranking metric
Requested generation and storage interconnection capacity by U.S. state, measured in gigawatts.
Direction
Descending. States with more requested queue capacity rank higher.
Source timing
The LBNL backbone runs through December 31, 2025. GridAlmanac reports ISO-region status refreshes through July 2026 where applicable. The page was checked September 7, 2026.
Value status
All 20 ranking rows are industry_observed_value. No state value is an official_value, calculated_value, official_forecast or modeled_projection.
Technology coverage
The source dataset includes multiple generation and storage technologies, including solar, batteries, wind, gas, offshore wind, nuclear and other resource types.
Coverage
GridAlmanac lists projects across 48 states. This page ranks the 20 states with the largest confirmed requested-capacity totals.
Inclusion and exclusion
Queue entries are proposed generation or storage projects requesting connection. They are not counted as operating plants or guaranteed future capacity.
What the metric does not measure
It does not directly measure congestion, curtailment, reliability, upgrade cost, electricity prices, transmission investment or project completion probability.
Assumptions
No missing values are imputed and no cross-source normalization is applied. Page-level totals assume that all displayed state values are comparable under GridAlmanac's common requested-capacity definition.
Data handling
GridAlmanac is the controlling source for state ranking values; LBNL is used for the underlying queue methodology and IEA for contextual analysis. Missing state values are not estimated. Conflicting values are not averaged; the ranking follows the current GridAlmanac state aggregation. Source values are displayed to two decimal places in GW, while calculated shares are rounded to one decimal place. States without a confirmed source value are not inserted into the ranking.
Why the national totals differ
GridAlmanac reports 1,787.79 GW of requested capacity using the primary component of each request. LBNL reports more than 2,060 GW of active generation and storage capacity at the end of 2025. GridAlmanac notes that the broader LBNL total also counts storage components of hybrid projects, so the figures use different definitions and are not combined.
Calculated page-level summaries
Top 20 total = 503.59 + 122.29 + 89.87 + 85.85 + 72.61 + 63.52 + 53.99 + 51.13 + 46.50 + 45.04 + 43.33 + 42.37 + 31.59 + 30.18 + 29.64 + 28.05 + 27.79 + 26.39 + 25.40 + 24.83 = 1,443.96 GW. Top 20 share = 1,443.96 ÷ 1,787.79 × 100 = 80.77%, displayed as 80.8%. These page-level summaries are calculated from observed inputs and are not forecasts or projections.
Main ranking: Top 20 U.S. states by requested queue capacity
| Rank | State | Requested capacity | Source / Method Note |
|---|---|---|---|
| 1 | Texas | 503.59 GW | industry_observed_value; GridAlmanac 2026 snapshot; 2,080 projects; ISO statuses through Jul 2026 where applicable; LBNL backbone through Dec 2025. |
| 2 | California | 122.29 GW | industry_observed_value; GridAlmanac 2026 snapshot; 413 projects; ISO statuses through Jul 2026 where applicable; LBNL backbone through Dec 2025. |
| 3 | Arizona | 89.87 GW | industry_observed_value; GridAlmanac 2026 snapshot; 278 projects; ISO statuses through Jul 2026 where applicable; LBNL backbone through Dec 2025. |
| 4 | Oregon | 85.85 GW | industry_observed_value; GridAlmanac 2026 snapshot; 323 projects; ISO statuses through Jul 2026 where applicable; LBNL backbone through Dec 2025. |
| 5 | Nevada | 72.61 GW | industry_observed_value; GridAlmanac 2026 snapshot; 247 projects; ISO statuses through Jul 2026 where applicable; LBNL backbone through Dec 2025. |
| 6 | Illinois | 63.52 GW | industry_observed_value; GridAlmanac 2026 snapshot; 343 projects; ISO statuses through Jul 2026 where applicable; LBNL backbone through Dec 2025. |
| 7 | Michigan | 53.99 GW | industry_observed_value; GridAlmanac 2026 snapshot; 279 projects; ISO statuses through Jul 2026 where applicable; LBNL backbone through Dec 2025. |
| 8 | Indiana | 51.13 GW | industry_observed_value; GridAlmanac 2026 snapshot; 249 projects; ISO statuses through Jul 2026 where applicable; LBNL backbone through Dec 2025. |
| 9 | Georgia | 46.50 GW | industry_observed_value; GridAlmanac 2026 snapshot; 204 projects; ISO statuses through Jul 2026 where applicable; LBNL backbone through Dec 2025. |
| 10 | Oklahoma | 45.04 GW | industry_observed_value; GridAlmanac 2026 snapshot; 218 projects; ISO statuses through Jul 2026 where applicable; LBNL backbone through Dec 2025. |
| 11 | Washington | 43.33 GW | industry_observed_value; GridAlmanac 2026 snapshot; 207 projects; ISO statuses through Jul 2026 where applicable; LBNL backbone through Dec 2025. |
| 12 | Colorado | 42.37 GW | industry_observed_value; GridAlmanac 2026 snapshot; 210 projects; ISO statuses through Jul 2026 where applicable; LBNL backbone through Dec 2025. |
| 13 | Louisiana | 31.59 GW | industry_observed_value; GridAlmanac 2026 snapshot; 121 projects; ISO statuses through Jul 2026 where applicable; LBNL backbone through Dec 2025. |
| 14 | Arkansas | 30.18 GW | industry_observed_value; GridAlmanac 2026 snapshot; 131 projects; ISO statuses through Jul 2026 where applicable; LBNL backbone through Dec 2025. |
| 15 | Utah | 29.64 GW | industry_observed_value; GridAlmanac 2026 snapshot; 153 projects; ISO statuses through Jul 2026 where applicable; LBNL backbone through Dec 2025. |
| 16 | New Mexico | 28.05 GW | industry_observed_value; GridAlmanac 2026 snapshot; 140 projects; ISO statuses through Jul 2026 where applicable; LBNL backbone through Dec 2025. |
| 17 | Missouri | 27.79 GW | industry_observed_value; GridAlmanac 2026 snapshot; 115 projects; ISO statuses through Jul 2026 where applicable; LBNL backbone through Dec 2025. |
| 18 | Kansas | 26.39 GW | industry_observed_value; GridAlmanac 2026 snapshot; 112 projects; ISO statuses through Jul 2026 where applicable; LBNL backbone through Dec 2025. |
| 19 | Wisconsin | 25.40 GW | industry_observed_value; GridAlmanac 2026 snapshot; 115 projects; ISO statuses through Jul 2026 where applicable; LBNL backbone through Dec 2025. |
| 20 | New York | 24.83 GW | industry_observed_value; GridAlmanac 2026 snapshot; 175 projects; ISO statuses through Jul 2026 where applicable; LBNL backbone through Dec 2025. |
The table is a compiled research dataset based on 3 sources, with row-level source and method notes shown in the ranking table. The 20 numeric ranking values themselves come only from GridAlmanac; LBNL provides the underlying queue dataset and methodology, while IEA is used only for broader grid-system context. No missing state values are estimated and no conflicting values are averaged.
Insights from the state queue ranking
Key Insight
Texas is the dominant outlier at 503.59 GW, about 4.1 times California's 122.29 GW.
Notable Pattern
The upper ranking spans western, central, southern and Midwestern states rather than one single U.S. region.
Regional/Source Concentration
The Top 20 account for 80.8% of the national requested-capacity total under the same GridAlmanac definition.
Outlier
New York at 24.83 GW is only 0.27 GW above Minnesota at 24.56 GW, the first state outside the Top 20.
What grid constraints mean for the energy transition
Read this ranking as a measure of requested access to the power grid, not as a direct score of congestion, reliability or transmission weakness. A high state value means more generation and storage capacity is represented in the interconnection queue under the GridAlmanac definition.
All 20 ranking rows are industry_observed_value records rather than official state-government values. They should be distinguished from official_value data published directly by an authority, calculated_value results derived from observed inputs, official_forecast values published as forecasts, and modeled_projection estimates produced from a base value and growth or scenario assumptions. No forecast or modeled projection is used in this ranking.
Interconnection is only one stage between developing an energy project and delivering electricity to customers. After connection, transmission congestion, local network limits, balancing requirements and curtailment can still restrict how much energy reaches the system and when it can be used.
IEA Electricity 2026 reports more than 2,500 GW of renewable generation, storage and large-load projects stalled in grid connection queues worldwide. The IEA estimates that planning, permitting and completing new grid infrastructure can take roughly 5 to 15 years, compared with about 1 to 5 years for solar PV and wind projects.
The same analysis states that annual global grid investment needs to rise by approximately 50% from today's roughly USD 400 billion by 2030.
More transmission is not the only tool
New lines and substations remain important, but the IEA also identifies faster connection processes, non-firm connection agreements, grid-enhancing technologies, dynamic line rating, power-flow control, reconductoring, voltage uprating, battery storage and greater demand-side flexibility as ways to use existing networks more effectively.
FAQ
What is an interconnection queue?
It is a pipeline of proposed generation or storage projects going through the process required to connect to the power grid.
Does this ranking show which state has the worst grid congestion?
No. It measures requested interconnection queue capacity. Congestion is a different operational condition involving limits on electricity transfer across the network.
Are the state values renewable-energy capacity only?
No. The source dataset includes multiple generation and storage resource types.
Are these official state-government values?
No. The ranking values are industry_observed_value published in GridAlmanac's state aggregation. GridAlmanac identifies LBNL Queued Up 2026 as the underlying project-level source.
Why is this called a 2026 snapshot?
The LBNL backbone runs through December 31, 2025, while GridAlmanac reports ISO-region status refreshes through July 2026 where applicable. The page was checked September 7, 2026.
Why do GridAlmanac and LBNL show different national totals?
GridAlmanac uses the primary component of each request, while LBNL's broader headline also includes storage components of hybrid projects.
Will all projects in the queue be built?
No. LBNL reports that 13% of capacity submitting interconnection requests from 2000 through 2020 had reached commercial operation by the end of 2025, while 75% had withdrawn.
How long can interconnection take?
For regions with available data, LBNL reports that the median time from interconnection request to commercial operation exceeded five years for projects completed in 2025.
How large is the grid-connection challenge globally?
IEA Electricity 2026 reports more than 2,500 GW of renewable, storage and large-load projects stalled in grid connection queues worldwide.
Sources
The table is a compiled research dataset based on 3 sources, with row-level source and method notes shown in the ranking table. GridAlmanac supplies the state ranking values, LBNL supplies the underlying queue dataset and methodology, and IEA supplies broader grid-system context. The sources are not averaged or blended into a synthetic ranking.
GridAlmanac — U.S. Interconnection Queue
Controlling numeric source for the state ranking, project counts, coverage and requested-capacity definition.
Lawrence Berkeley National Laboratory — Queued Up 2026
Underlying project-level research source and methodology for active queue capacity, timing and historical outcomes.
International Energy Agency — Electricity 2026: Grids
Contextual source for global connection queues, grid-development lead times, investment requirements and grid-enhancing solutions.
