Permitting Success: 90% of U.S. Solar and Wind Projects Are Getting Approved — Here's What the Data Actually Shows
New research shows that 90% of solar projects receive timely permits across 19 states. What does this mean for the future of clean energy?
Permitting horror stories dominate industry conversations. Projects stall for years, bureaucratic mazes ensnare applicants, and local opposition turns routine approvals into referendums. However, when researchers dig into the data, the findings can contradict the conventional narrative in ways worth paying attention to.
A new study from Berkeley Lab and the University of Massachusetts Amherst examined solar project permitting outcomes across 19 states and found that 90% of large-scale solar and wind projects that reached a permit decision were approved. Not just approved, but mostly within about a year of application. For an industry that often treats permitting as an existential bottleneck, that number deserves serious examination.
What the Research Actually Found
The study, published in *Frontiers in Sustainable Energy Policy*, analyzed 460 projects with permit applications filed between 2018–2024 for solar and 2015–2024 for wind. Of those, 365 reached a final outcome — 95 were still pending review. Among the 365 completed cases, nine out of ten received approval.
The 10% that didn't make it broke down across withdrawals by developers, outright denials, permits terminated before a decision, and one case of a previously approved permit being revoked. That last category — developer withdrawals — is important context. A project pulled from review isn't necessarily a regulatory failure; developers exit for economic reasons, site control issues, or because they sensed trouble ahead. Lumping withdrawals in with denials would tell a different story than the one the data supports.
The researchers were direct in their conclusion: for the 19 states evaluated, state-level permitting processes "are not preventing new potential energy from entering the grid."
That's a meaningful statement. It doesn't mean permitting is frictionless — it means the state-level approval stage, specifically, is not the primary chokepoint.
Why Some States Move Faster Than Others
Six states had at least 20 projects with a known outcome, providing enough data to draw meaningful comparisons. The spread in processing times tells a nuanced story.
Kentucky and Mississippi averaged roughly seven months to reach a permit outcome — the fastest in the group. The researchers flag something important here: developers in those states may only be applying *after* their projects are already in compliance with local regulations. In other words, by the time an application hits the state desk, the heavy lifting is done. The speed isn't evidence of a permissive process; it may reflect a more selective applicant pool.
Maryland, Minnesota, New York, and Ohio averaged about 15 months. Those states generally preempt local authority over large energy facilities — meaning developers can bring projects that might face opposition at the county or municipal level directly to the state. That preemption authority likely draws in a broader range of applications, including more complex or contentious projects. Higher volume and more complex cases naturally stretch timelines.
The other 13 states in the study — including California, Nevada, Oregon, Washington, Wisconsin, and Wyoming — had fewer than 20 projects with known outcomes, limiting what conclusions can be drawn. That's not a knock on those states; it reflects data availability constraints, which the researchers acknowledge upfront.
The Real Bottleneck Isn't the Permit
Here's the part that cuts against any triumphalist reading of the 90% approval figure: state permitting may be the easy part.
The researchers are explicit that interconnection — securing an agreement to physically connect a project to the transmission grid — presents "substantial and increasing" wait times and costs. That's well-documented at this point. The interconnection queue managed by grid operators like MISO, PJM, and CAISO has become a years-long gauntlet. Projects can receive every state permit they need and still sit idle for three to five years waiting for a grid study to complete and a connection agreement to be signed.
This is where the developer community's frustration is most concentrated, and for good reason. FERC's Order 2023 introduced reforms to the interconnection process in 2023, but the backlog is severe enough that meaningful relief is still years away for many projects. A solar developer in the mid-Atlantic who clears state permitting in 12 months may then spend 36 months in the interconnection queue. The permit was never the problem.
The study's findings don't minimize interconnection challenges — they actually sharpen the focus on where reform energy should be directed.
What Developers Can Learn From the Data
The study can't be read as a simple playbook, but it does point toward some patterns worth internalizing for anyone navigating energy facility permits.
States where developers apply only after meeting local requirements move fastest. That's not a coincidence — it reflects the value of front-loading due diligence. A project that arrives at a state agency with community support, completed environmental assessments, and resolved land control issues is a fundamentally different application than one that's hoping the state will sort out what local opposition couldn't.
The preemption states — New York, Maryland, Minnesota — attract more projects precisely because developers know they can bypass hostile local bodies. But that broader funnel also means more scrutiny, longer review, and higher stakes for each application. Developers using state preemption as a workaround for local opposition should expect the state process to be more rigorous, not less.
One practical limitation the researchers encountered: the permitting data "exhibited complex hierarchical relationships," with individual projects often carrying multiple applications, decision stages, and regulatory interactions. They had to build a relational database structure just to analyze it properly. That complexity isn't just an academic inconvenience — it's a daily reality for project teams managing multiple regulatory tracks simultaneously. Developers who underinvest in permitting coordination and data management pay for it in delays.
What Comes Next
The study analyzed 19 states because those were the only ones where permitting data was publicly accessible through a state website or database. The researchers specifically call out local-level permitting analysis as an important area for future work — but note it would be "severely limited by data availability and accessibility."
That data gap matters. County and municipal permitting is where much of the real friction lives, particularly for projects that don't qualify for state preemption. Local zoning boards, county commissions, and township trustees have enormous power over project siting, and their decisions are often poorly documented and inconsistently tracked. The next frontier for clean energy research — and advocacy — is building the same analytical clarity at the local level that Berkeley Lab has started to create at the state level.
Regulatory momentum on permitting is real. The conversation has shifted from whether permitting reform is needed to which specific processes to target. But as long as interconnection queues stretch to five-plus years and local permitting data remains a patchwork, the 90% state approval rate is a bright spot in a landscape that still has significant structural work ahead.
For developers, the takeaway is practical: state-level permitting, in most cases, is winnable — if you do the work before you apply.
Explore more about how to navigate the permitting process effectively at InfraSale Marketplace.