What Is the PJM Interconnection Queue and How It Works
The PJM interconnection queue is the ordered list of generation and storage projects seeking permission to connect to the PJM grid, the largest US power market. Your queue position and study timeline determine when you can sign an interconnection agreement, which anchors bankability and sequences your path to FID. This guide explains PJM's process, then compares queue mechanics across MISO, ERCOT, NYISO, SPP, and CAISO in a single reference.
Key takeaways
- The PJM interconnection queue is the ordered list of generation and storage projects seeking permission to connect to the PJM grid, and your position determines when you can sign an interconnection service agreement.
- PJM replaced first-come, first-served serial studies with an annual cluster window that requires readiness deposits, site control, and fees scaled to project size.
- Berkeley Lab found the typical project across ISOs takes about five years from interconnection request to commercial operation, so underwrite the interconnection agreement date, not the study start date.
- ERCOT skips the conventional queue entirely, trading slow serialized review for front-loaded capital obligations like letters of credit and signed agreements before studies begin.
- An executed interconnection service agreement is a financing milestone: without it, lenders will not treat projected revenues as bankable, so sequence offtake and study timelines in parallel.
What is an interconnection queue?
An interconnection queue is the line a project joins to get permission to connect to the transmission grid. Grid operators, called ISOs or RTOs, run these queues because every new generator, storage site, or load (like a waste-to-fuel facility) changes power flows on the network. Before you can connect, the operator must study whether your project requires transmission upgrades, and who pays for them.
A request typically specifies the project's size in megawatts, its location, the point of interconnection, and the requested in-service date. The operator then runs feasibility, system impact, and facilities studies to price the network upgrades your project triggers. PJM, the largest US grid operator, describes these study phases and its shift to cluster-based processing on its interconnection process page.
The queue exists because physical grid capacity is finite and shared. Your queue position, study timeline, and assigned upgrade costs become inputs to bankability: without an executed interconnection agreement, lenders and offtakers have no assurance your project can deliver power. That makes queue sequencing a first-order question for what makes an energy project financeable.
How does the PJM interconnection queue process work?
From application to interconnection service agreement
PJM's process runs in stages. You file an interconnection request during an open application window. PJM then runs studies in sequence: a feasibility study to estimate cost and timeline, a system impact study to model grid effects, and a facility study to price the specific network upgrades assigned to your project. Once studies clear, you execute an interconnection service agreement, which is the document lenders and offtakers treat as the grid-access milestone.
What makes this sequence hard for a founder-CEO is that each stage consumes cash and calendar before producing anything you can put in a data room. A feasibility study tells you a number that the system impact study can revise, and the facility study can revise again. Until the interconnection service agreement is signed, your grid access is a claim, not an asset. That is why interconnection sequencing belongs in your capital narrative from the seed round onward, not as a line item discovered during diligence. If your project is a waste-to-fuel plant, the same logic applies to feedstock and offtake contracts: nothing is bankable until it is contracted, and we break down what that means in what makes a waste-to-fuel project financeable. PJM has also shifted from first-come, first-served serial studies to cluster-based studies, where batches of projects are studied together and costs are allocated across the cluster.
Fees, deposits, and milestones
Expect application fees and study deposits scaled to project size, with larger deposits due as you pass each milestone. Withdraw or miss a milestone and you forfeit money and your place in the cluster. Site control and a completed system impact study are typically prerequisites before you reach an agreement, so budget for engineering spend well before FID.
How long do PJM interconnection requests take?
Under PJM's pre-cluster rules, projects that reached completion spent a median of roughly 2.5 to 3 years in the queue from request to interconnection agreement, with some waiting far longer. Berkeley Lab's national analysis found the typical project across ISOs took about 5 years from request to commercial operation. See Queued Up, Berkeley Lab.
Today the sequence runs longer on paper: a feasibility study, a system impact study, and a facility study before PJM issues an interconnection agreement for execution. Each phase has a posted window, but restudies, network upgrades, and withdrawal-driven resequencing stretch real timelines past the posted dates.
For FID sequencing, underwrite the interconnection agreement date, not the study start date, and treat the gap as your development-capital carry. We break down what makes a project financeable through that stretch at sharoncreek.com.
What changed in PJM's queue after the transition to cluster studies?
Why PJM reformed the queue?
PJM ran its interconnection studies serially, first-come-first-served, for years. Speculative projects piled up ahead of serious ones, and study timelines stretched long enough that the queue became a bottleneck for anyone approaching FID. The reform replaced the serial process with an annual cluster window: all requests submitted in that window are studied together, and the queue clears in batches rather than one project at a time.
What the readiness requirements demand from developers?
The trade-off is that entry now costs real money. Cluster applications require readiness deposits, site control for the requested capacity, and fees that scale with project size, all designed to filter out projects that were never going to be built. For a founder sequencing toward bankability, that changes the calculus: you submit when you have a site locked up, capital for the deposit, and a credible path to offtake, not when you want to reserve a spot. The discipline mirrors what project finance lenders expect anyway, so treat the readiness package as a dry run for your FID materials, as we argue in what operating decision should industrial AI improve.
How does the PJM queue compare to the MISO interconnection queue?
Both ISOs have replaced serial studies with cluster-based cycles, but the mechanics differ in ways that shape your FID sequencing. PJM runs a single annual cluster window with readiness requirements and a phased study structure. MISO runs phased study cycles (DPP Phases 1–3) within its annual cycle, letting smaller and readiness-qualified projects move through faster than the full cohort. Eligibility hinges on site control and application readiness rather than project size alone.
| Mechanic | PJM | MISO |
|---|---|---|
| Study structure | Cluster studies, phased | Annual cluster plus phased study cycles (DPP Phases 1–3) |
| Windows | One per year | Multiple phased study cycles (DPP Phases 1–3) |
| Fast path | None formal | Phased study cycles (DPP Phases 1–3) for ready projects |
For a founder sequencing offtake against an interconnection date, MISO's phased study cycles can compress the gap between signed feedstock and a financeable queue position. We track both clocks for clients at Sharon Creek Ventures, because queue timing is often the binding constraint on FID, not capital.
How do ERCOT, NYISO, SPP, and CAISO queues differ from PJM's?
ERCOT: no queue, different risk
ERCOT does not run a conventional interconnection queue. Because the Texas grid is not synchronized with the Eastern Interconnection, ERCOT requires new generation to be simultaneously operable and financially committed: you post a letter of credit and show a signed agreement before your study even starts. That compresses timeline risk into capital-at-risk instead. For a founder, ERCOT trades a slow, serialized review for a front-loaded funding obligation, and it removes federal cost-allocation fights because ERCOT's transmission is planned regionally.
NYISO, SPP, and CAISO cluster mechanics
NYISO, SPP, and CAISO all use cluster study windows rather than PJM's single annual cluster window. CAISO opens application windows and processes a large cohort together, with a phased deposit structure that escalates as your project survives each screen. SPP runs cluster studies on a fixed schedule and assigns network upgrades by zone. NYISO combines cluster studies with a separate Class Year process for facilities, so timing depends on which window your project lands in. In all three, a missed window means waiting for the next cohort, which can push FID by a full cycle.
How do developers track their position in the queue?
Every ISO publishes queue data, but the formats differ. PJM posts its queue and study status on its interconnection pages, MISO and CAISO offer downloadable queue exports, and ERCOT publishes a monthly report of signed interconnection agreements and permit applications. ERCOT's generation interconnection documentation also explains its connect-and-manage approach, where projects can interconnect before all transmission upgrades are complete and are managed for reliability rather than waiting out the full study cycle.
When diligencing a pipeline, look past queue position. Ask for the feasibility or cluster study results, the cost allocation letter, and the milestone dates for the interconnection agreement. A founder who can produce those documents has a defensible timeline; one who quotes only "we're in the queue" does not.
What does queue position mean for bankability and FID?
An executed interconnection service agreement is a financing milestone, not a technical one. Until you hold one, your project has no assured grid access, and lenders structuring project finance will not treat projected revenues as bankable. The ISA converts a queue position into a contracted right, which is why it belongs on the critical path alongside offtake.
Sequence the three clocks deliberately. Offtake negotiations and the interconnection study should run in parallel, since a power purchase agreement without a delivery date, or an ISA without a buyer, fails FID either way. Raise capital against the milestone you can hit next: seed and Series B fund technology and early development; project equity and debt price off the ISA, feedstock contracts, and permitted site.
The practical rule: never let the venture clock force an FID date the interconnection queue cannot support.
FAQ
How much does it cost to enter the PJM interconnection queue?
Costs scale with project size. You pay an application fee, study deposits that increase as your project passes each milestone, and readiness requirements including site control. Larger deposits come due at later phases, and withdrawing or missing a milestone forfeits both the money paid and your place in the cluster, so budget engineering spend well before FID.
Can you sell your position in an interconnection queue?
Not directly. A queue position is a claim, not a contracted right, so there is no market for selling a spot. What developers do instead is sell the project entity holding the request, which transfers the position along with its study obligations, deposits, and site control. The buyer inherits the milestone schedule and any upgrade costs already assigned.
Which ISO has the fastest interconnection queue?
ERCOT is the fastest by design, because it skips the conventional queue entirely. You post a letter of credit and show a signed agreement before studies start, then interconnect under connect-and-manage rules rather than waiting for all upgrades. Elsewhere, timelines run years: Berkeley Lab found the typical project takes about five years from request to commercial operation.
What is the difference between an interconnection study and an interconnection service agreement?
A study is an estimate; an interconnection service agreement is a contract. Studies, including feasibility, system impact, and facility phases, price the network upgrades your project triggers, and later studies can revise earlier numbers. The ISA is the executed document that converts your queue position into an assured grid-access right, which is what lenders and offtakers treat as bankable.