Getting a wind turbine or a field of solar panels approved in Massachusetts takes, on average, 250 days from application to decision, according to the first systematic study of locally-permitted renewable energy projects in the United States. The median wait is shorter, 173 days, but the trend line is moving in the wrong direction: projects decided between 2020 and 2025 took significantly longer than those decided a decade earlier. The finding matters far beyond New England, because local governments, not states, hold the primary permitting authority for most solar and onshore wind projects across the country, and almost nobody has ever measured how long those approvals actually take.
The research, published in Frontiers in Sustainable Energy Policy, was conducted by a team from the University of Massachusetts Amherst, Lawrence Berkeley National Laboratory, and the University of California, Santa Barbara. Led by Natalie Baillargeon and Juniper Katz, the researchers built an original dataset from scratch, because no existing database tracks the full population of renewable energy projects that enter a permitting process. Federal sources such as the U.S. Energy Information Administration’s generator inventory and the U.S. Large-Scale Photovoltaic Database record projects that ultimately get built, but they are silent on the ones that stall, get denied, or quietly die in a town boardroom.
Massachusetts offers an unusually instructive case. Under the state’s home-rule framework, land use authority flows from the state to its 351 cities and towns, and the authority having jurisdiction over a renewable energy project depends on its size. Only projects exceeding 100 megawatts of installed capacity, a threshold that drops to 25 megawatts after March 2026, fall under state review, and to date no project has been large enough to trigger that preemption. The result is a patchwork in which each municipality runs its own process under limited state guidance, with state law touching mainly the transparency of public hearings and the structure of meetings rather than the substance of decisions.
That patchwork is precisely what makes timelines hard to measure. The researchers searched exhaustively for permitting records in 41 towns, roughly 21 percent of Massachusetts municipalities known to host at least one project in federal data, and ultimately collected usable data from 25. Because the state had no unified permitting portal during the study period, most towns offered no public database at all. The team pieced together timelines from 131 documents, including meeting minutes, site plans, permit applications, developer letters, and news coverage, averaging five documents per project. When records were missing, they contacted local officials directly, often without success. In one case, an official reported that records of canceled projects were destroyed due to limited storage resources.
From that effort, the researchers assembled complete application and decision dates for 26 projects across 17 towns and six counties, spanning decisions from 2009 to 2023. The sample skews heavily toward solar: 88 percent of the projects were solar or solar-plus-storage, with only two onshore wind projects, in Cambridge and Plymouth. Capacities ranged widely, with 46 percent of projects at or below 2 megawatts, the state’s median project size, and 27 percent at or above 5 megawatts. Most projects, 77 percent, entered permitting after 2017, reflecting the recent surge in distributed solar development across the Commonwealth.
The statistical analysis relied on non-parametric methods appropriate for the small, skewed sample. Kruskal-Wallis tests compared permitting durations across three explanatory variables: decision year, permit status, and installed capacity. The decision-year result was striking. Median durations differed significantly across the three year groups, with a large effect size, and projects decided between 2020 and 2025 took significantly longer than those decided between 2009 and 2014. The trend held even when the analysis was restricted to projects that ultimately received permits, suggesting the slowdown is not simply an artifact of more contested projects entering the recent sample.
Permit status told a related story. Projects that won approval had the shortest permitting durations, while canceled projects and those entangled in litigation had longer ones. Ten percent of the sample was under active lawsuit at the time of the study, with challenges typically filed by project opponents and centered on land use concerns such as environmental and viewshed impacts. The researchers reviewed letters from project abutters, and every one of them either called for permit denial or raised concerns, citing drinking water contamination, groundwater runoff, and the environmental effects of deforestation. Because variance across status groups was heterogeneous, the team did not formally test statistical significance for this comparison, but the descriptive pattern aligns with a growing national literature on renewable energy opposition.
Project size, by contrast, showed no statistically significant relationship with permitting duration across the three capacity groups, a result the authors attribute partly to limited sample sizes. The more provocative finding is the temporal one, and the researchers offer two competing explanations. One is geographic: Massachusetts is densely populated, with competing demands for housing and agriculture, and the easiest sites may already host energy projects. Recent proposals may therefore land in less desirable locations, such as forests, farmland, or parcels close to neighbors, any of which can complicate review. The other is social: a rising regional or national conflict around wind and solar projects, documented by other scholars, may be lengthening deliberations everywhere. Distinguishing between these hypotheses is a task for future research.
The timing of the study is not accidental. Massachusetts enacted Chapter 239 of the Acts of 2024 in November 2024, a permitting reform law that directs agencies to establish standards, consolidate local permitting processes, impose binding timelines on local decisions, strengthen community engagement, and provide technical support to towns. The new law requires a permitting decision within one year of application, a threshold that 81 percent of projects in the study sample already met, though the rising trend suggests that margin could erode. At least 47 state governments are currently grappling with similar permitting reforms, and the authors argue that Massachusetts’ baseline data provide an essential benchmark for evaluating whether such reforms actually accelerate deployment.
The study also exposes an uncomfortable governance problem: the data needed to make evidence-based permitting policy largely do not exist. Unlike state-level authorities, which typically maintain public permitting portals, small local governments often lack databases, formal record retention practices, or the staff capacity to maintain them. The authors argue that public data transparency requirements for recorded decisions on energy projects would standardize information and enable tracking of permitting steps and durations, while acknowledging that under-resourced towns cannot absorb such mandates without funding and capacity support. Massachusetts’ new law mandates a clean energy dashboard covering all projects regardless of jurisdiction, which may address the gap, but questions remain about enforcement and the burden on municipalities. In the absence of such transparency, the researchers warn, it will remain very difficult to evaluate how permitting policy shapes the pace of the clean energy transition, in Massachusetts or anywhere else.
Subject of Research: Permitting timelines and outcomes for locally-permitted wind and solar energy projects in Massachusetts
Article Title: Permitting and siting of wind and solar in Massachusetts: processes, timelines, and outcomes
Article References: Baillargeon, N., Katz, J., Tao, L., Nilson, R., & Hoen, B. (2026). Permitting and siting of wind and solar in Massachusetts: processes, timelines, and outcomes. Frontiers in Sustainable Energy Policy, 5, Article 1771870. https://doi.org/10.3389/fsuep.2026.1771870
Image Credits: AI Generated
DOI: 10.3389/fsuep.2026.1771870
Keywords: permitting, siting, solar energy, wind energy, Massachusetts, local governance, energy policy, renewable energy, land use, permitting reform, community opposition, administrative burden
