The clean energy pipeline in the United States is large enough, on paper, to meet demand several times over. Lawrence Berkeley National Laboratory (LBNL), which tracks every major grid operator's interconnection queue, reported over 2,060 gigawatts (GW) of total generation and storage capacity actively seeking grid connection as of the end of 2025. That is roughly twice the installed capacity of the entire current U.S. power plant fleet. The problem is not the size of the pipeline. The problem is the share of it that moves.
Most projects that enter the interconnection queue do not make it to commercial operation. Only 13% to 19% of projects that requested interconnection between 2000 and 2019 had reached commercial operation by the end of 2023, according to LBNL and RMI data cited by the University of Chicago's Sustainability Dialogue. The median time from an initial interconnection request to commercial operation has roughly doubled compared to projects built in the early 2000s, reaching close to five years for recent projects. Those figures describe a system that is processing capacity additions far more slowly than the rate at which projects are being proposed, and the gap has not closed in the years since.
The Withdrawal Spike in 2025 Was Not Random. The OBBBA Accelerated It.
The LBNL data through the end of 2025 shows that Q3 and Q4 of that year posted the highest project withdrawal volumes on record, driven at least in part by the tax credit changes introduced by the One Big Beautiful Bill Act (OBBBA). The OBBBA shortened eligibility deadlines for wind and solar projects, requiring construction to begin by July 4, 2026, to qualify for production and investment tax credits under the Inflation Reduction Act (IRA) frameworks established by Sections 45Y and 48E, before those credits begin phasing out entirely in 2027. Projects sitting in interconnection review with no clear timeline for approval faced a straightforward calculation: continue waiting in a queue that might not resolve before the eligibility deadline, or withdraw and cut losses. Many withdrew.
The LBNL data also shows that the withdrawal pattern was not distributed evenly across technologies. Renewable energy capacity continues to see record growth across major markets while natural gas additions take a smaller share of the grid. However, the pace of the clean energy transition remains constrained by sharp differences in lender behavior and structural risks: gas projects bypass the severe interconnection cost hikes and timeline uncertainties that solar and wind projects face in overloaded queues, and they do not depend on the complex federal tax equity markets required to finance renewables.
Federal Permitting and Interconnection Are Different Problems That Compound Each Other
Federal permitting and interconnection are not the same bottleneck, but they interact. A project can clear federal environmental review and still face years in the interconnection queue waiting for a cost allocation and study completion. Conversely, a project can secure a favorable interconnection position and then encounter federal permitting exposure that was not apparent at the time of the queue application.
What This Means for Operations and Procurement Teams With Contracted Supply
The implications for corporate energy buyers are more direct than they tend to appear in planning conversations. A power purchase agreement (PPA) signed with a project currently in the interconnection queue is a contract tied to a delivery timeline that the developer does not fully control. PJM's Maryland and D.C. queue alone contains more than 5,000 megawatts (MW) of generation driven almost entirely by solar, storage, and hybrid projects, according to PJM's 2025 Regional Transmission Expansion Plan. The Maryland People's Counsel has noted publicly that interconnection study timelines frequently outlast developer financing, forcing projects to effectively restart from the beginning even after receiving interconnection approval.
Operations and procurement teams that have built load management, decarbonization targets, or sustainability reporting timelines around specific contracted renewable supply need to understand where in the process those projects actually sit. A project with a signed PPA and an active interconnection application is not the same as a project with a clear path to commercial operation on a defined schedule. The 2,060 GW in the queue is not all equivalent. The share of it that will deliver power on the timeline buyers are planning around is considerably smaller, and right now the forces compressing that share are running in the same direction at once.
