Interconnection queues are no longer a side story in clean-energy development, they’re the main plot. By late 2024, U.S. transmission operators reported more than 2,600 GW of proposed generation and storage waiting for a path to the grid, more than twice the country’s current installed capacity. (Berkeley Lab, 2024)
We know the interconnection backlog headline all too well: projects are waiting years for studies and upgrades. But numbers only tell part of the story. From our vantage point, supporting developers and utilities in multiple markets, we see subtler patterns emerging.
What the Data Really Shows about the Interconnection Backlog
- Projects are slow to reach the finish line. Historical data show only ~19% of projects entering U.S. queues between 2000–2018 have reached commercial operation (Berkeley Lab, 2024).
- Timelines keep stretching. Median time from request to operation now averages about five years, up from under two decades ago.
- Costs vary widely. In PJM, completed projects between 2020–2022 averaged interconnection costs of $240/kW, while withdrawn projects faced about $599/kW (DOE I2X, 2024).
These figures are well known, but their implications are still unfolding in day-to-day project planning.
Patterns We’re Seeing in the Field
Restudies are the hidden delay. When projects drop out or change configuration, the remaining proposals must be re-analyzed. Even well-prepared projects can be pushed back through no fault of their own.
Transmission upgrades are the long pole. Study timelines are only part of the wait. Permitting and building the physical upgrades—new lines, substations, transformers—often outlast the study process.
Rules differ by market. Cluster studies, first-ready/first-served criteria, and cost-allocation methods vary across RTOs. Developers operating in multiple regions face a moving target of procedures and expectations.
How Policy Is Shifting
Recent reforms, such as FERC Order 2023, aim to reduce speculation and encourage readiness by grouping projects into clusters and rewarding completeness. Some markets (e.g., MISO, PJM, CAISO) have begun implementing these changes, while others are still in transition.
These reforms hold promise, but uneven rollout means that market-specific nuance remains critical. Early adopters are experimenting with new models such as “connect and manage,” which allows limited interconnection while longer-term upgrades are planned.
What we’re observing
At ZEG, we’re staying on top of these evolving changes. We analyze transmission constraints and study results for developers and utilities. From this work, a few observations stand out:
- High-fidelity data matters. Projects with robust modeling and complete technical packages still face delays, but they experience fewer restudy triggers and clearer cost estimates.
- Location remains decisive. Even under cluster models, headroom and upgrade needs vary dramatically across substations and corridors.
- Policy engagement pays off. Teams that follow stakeholder processes closely are better positioned to anticipate rule changes that can affect timing or cost.
These aren’t prescriptions, they’re recurring themes we see across dozens of projects and markets.
The Future for the Interconnection Backlog
The interconnection backlog reflects a fundamental tension: clean-energy deployment is accelerating faster than the transmission system can adapt. Queue reform, transmission expansion, and grid-enhancing technologies will all play a role, but none offer a quick fix.
Our perspective is cautious optimism. The shift toward cluster studies and readiness criteria is a necessary step, and markets that combine these reforms with proactive transmission planning are already showing signs of improved throughput.
The queue challenges are well publicized, but the lived experience is more complex than a single headline. By sharing data, lessons, and patterns we observe in daily project work, we hope to add clarity to a process that remains one of the most critical, and solvable, barriers to a clean-energy grid.
We are dedicated to sharing valuable insights as queue reforms unfold. If you’re seeing patterns or pain points in your own interconnection experience, we’d like to hear them, your perspective helps shape the dialogue. Contact us to talk interconnection or to explore our array of services and solutions.
Resources:
Berkeley Lab – “Queued Up: Characteristics of Power Plants Seeking Transmission Interconnection in the United States” (2024 Edition)
Lawrence Berkeley National Laboratory.
https://emp.lbl.gov/queues
(Source for total U.S. queue capacity, completion percentages, and median wait times.)
U.S. Department of Energy (DOE) – Interconnection Innovation e-Xchange (i2X): Tackling High Costs and Long Delays in Clean Energy Interconnection
https://www.energy.gov/eere/i2x
(Background on interconnection cost trends and policy initiatives.)
Federal Energy Regulatory Commission (FERC) – Order No. 2023: Improvements to Generator Interconnection Procedures and Agreements
https://www.ferc.gov/media/order-no-2023
