For years, the long list of power plants waiting to plug into the American grid was overwhelmingly green. Solar farms and wind projects filed applications by the thousands, often speculatively, turning the national interconnection queue into a rough scoreboard for renewable energy ambition. That scoreboard looks very different now.
Natural gas and nuclear projects together account for roughly 55% of all proposed generating capacity sitting in U.S. interconnection queues, according to the 2025 edition of the Berkeley Lab queue study, which tracks every active project request filed with the nation’s major transmission providers through the end of 2024. The finding marks a striking reversal from recent years, when renewables and battery storage dominated the pipeline by a wide margin.
The shift matters because the queue is the first bottleneck every new power plant must pass through. Before a single turbine spins or a reactor heats up, the developer must file a formal interconnection request asking the regional grid operator to study whether the project can physically connect to transmission lines without destabilizing the system. What sits in that queue today shapes what gets built, and what does not, over the next decade.
The numbers behind the reversal
The Berkeley Lab report, formally titled “Queued Up: 2025 Edition, Characteristics of Power Plants Seeking Transmission Interconnection As of the End of 2024,” draws on filings submitted through FERC’s public data portal and records from individual transmission providers such as PJM, MISO, ERCOT, and the California ISO. It is the most comprehensive public accounting of the U.S. power plant development pipeline, updated annually since 2008.
Previous editions told a consistent story: solar, wind, and battery storage proposals were flooding the queue, pushing total pending capacity past 2,500 gigawatts by some estimates, far more than the roughly 1,300 GW of generation the country actually operates. Gas and nuclear were present but modest. The 2025 edition shows gas-fired plants and nuclear reactors, including a growing number of small modular reactor designs, have surged to claim a combined majority of proposed capacity.
Solar and wind projects have not disappeared. They still represent large volumes of proposed capacity. But the balance has shifted enough that dispatchable, firm power sources now hold the dominant share, a change that carries real implications for grid reliability planning, emissions trajectories, and state clean energy targets.
Why gas and nuclear are gaining ground
No single factor explains the swing, and the Berkeley Lab report documents the pattern without attributing it to specific causes. But several forces are converging.
Electricity demand is climbing after nearly two decades of relative flatness. Data centers powering artificial intelligence workloads, manufacturing facilities reshoring to the U.S., and widespread electrification of vehicles and buildings are all pulling load growth projections upward. Grid operators in regions like PJM, which serves 65 million people across 13 states, have publicly flagged the risk that demand could outpace new supply, particularly if large baseload plants retire before replacements come online.
Gas-fired plants offer something renewables alone cannot: on-demand generation that runs regardless of weather. Utilities and merchant developers see gas as a hedge against reliability gaps, especially after high-profile grid emergencies during Winter Storm Uri in 2021 and Winter Storm Elliott in 2022 exposed vulnerabilities in systems that depend heavily on variable resources.
Nuclear, meanwhile, is experiencing a policy-driven renaissance. Federal loan guarantees, production tax credits extended under the Inflation Reduction Act, and growing bipartisan support for advanced reactor designs have lowered the financial barriers for developers. Several utilities have signed letters of intent or memoranda of understanding for small modular reactors, and the Nuclear Regulatory Commission is reviewing multiple design applications.
FERC’s new rules are filtering the queue
A major structural change is also reshaping which projects survive the queue process itself. In 2023, the Federal Energy Regulatory Commission issued Order No. 2023, replacing the old first-come, first-served serial study method with a “first-ready, first-served” cluster study framework. Under the new rules, developers must post financial deposits and demonstrate site control and engineering readiness before their projects advance through study phases.
The old system had become badly clogged. Thousands of speculative renewable applications, many filed at minimal cost with no firm financing behind them, created backlogs stretching five years or longer. Viable projects waited in line behind paper proposals that would never break ground. FERC designed Order No. 2023 to clear that logjam by raising the cost of staying in the queue and rewarding projects that are genuinely ready to build.
Gas and nuclear projects tend to clear these readiness hurdles more easily. Gas plants rely on established financing structures, proven turbine technology, and relatively short construction timelines for the capacity they deliver. Nuclear proposals increasingly arrive backed by federal loan commitments or long-term utility procurement agreements. Many early-stage renewable projects, by contrast, depend on power purchase agreements still under negotiation or tax credit allocations that have not yet been finalized, making it harder to meet the new financial commitment thresholds.
The result is a queue that increasingly reflects serious development intent rather than speculative interest, and that filtered view favors the kinds of capital-intensive, dispatchable projects that gas and nuclear represent.
What the queue does not tell us
A critical caveat: the interconnection queue is not a construction forecast. It is a catalog of developer intent, and historically, most projects that enter the queue never reach commercial operation. Completion rates have been low across all fuel types. Solar and wind saw especially high dropout rates in earlier years because so many applications were speculative or duplicative.
Whether gas and nuclear projects will complete at higher rates under the reformed process is an open question. Order No. 2023 is still being implemented by transmission providers, and some regions are only now transitioning to cluster studies and higher readiness thresholds. The 2024 snapshot captured by Berkeley Lab reflects a mix of legacy and reformed processes, meaning the current surge in gas and nuclear proposals could be a temporary spike rather than the start of a durable trend.
There is also a potential collision between federal interconnection policy and state clean energy mandates. More than 30 states have adopted renewable portfolio standards or clean energy goals, according to tracking by the National Conference of State Legislatures. If the reformed queue process structurally advantages conventionally financed projects, states could face a mismatch between what their policies require and what the grid approval pipeline delivers. No official analysis from FERC or Berkeley Lab quantifies that tension yet.
Where the power pipeline is heading
For grid operators, utility planners, and energy investors, the message from the latest queue data is hard to miss. The development pipeline is no longer a proxy for renewable momentum alone. Gas and nuclear developers are filing substantial, capital-intensive projects in volumes large enough to claim a majority of proposed capacity for the first time in years.
That does not mean renewables are fading. Solar, wind, and storage still represent enormous volumes of proposed generation, and falling hardware costs continue to make them competitive in many markets. But the queue now reflects a more contested landscape, one where reliability concerns, surging electricity demand, and tighter interconnection rules are pulling investment toward firm, dispatchable power sources.
Future editions of the Berkeley Lab study will reveal whether this shift hardens into a long-term pattern or softens as FERC’s reforms mature and renewable developers adapt to the new rules. For now, the data point in one direction: the era when the interconnection queue belonged almost exclusively to wind and solar is over, and the competition for grid access is more crowded, and more consequential, than it has been in years.
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*This article was researched with the help of AI, with human editors creating the final content.
