Is my community solar project stuck because of interconnection?

Often, but not always. Community solar also depends on a state program slot and a local ComEd hookup, so ask the developer which step the project is actually waiting on.

Does all of Illinois use PJM?

No. Northern Illinois, including Chicago and most of ComEd's territory, is in PJM, while central and southern Illinois sit in a different grid operator, MISO. The queue rules differ between them.

Why did PJM pause new applications?

The old one-by-one study process could not keep up with the flood of solar and storage requests. PJM moved to studying projects in clusters and prioritizing the ones ready to build, with federal approval.

If a project has an in-service date, will it connect by then?

Maybe. Dates in the queue slip often as studies and upgrades take longer than expected, so treat any single date as an estimate and watch for status changes instead.

The interconnection line Illinois solar and storage are waiting in

I.How a project gets in line

The study is the heart of it. PJM engineers model what happens when a proposed project plugs in: whether the local wires and substations can carry the extra power, what equipment would need upgrading, and who pays for those upgrades. A small rooftop on an existing circuit may need little. A large solar and storage site on a rural feeder may trigger upgrades that cost more than the project can bear, which is often when a developer walks away.

Under the new approach, projects move through the queue in clusters rather than as a long single-file line. PJM is working through a backlog of earlier requests in transition cycles before the steady-state process takes over, and each cycle runs through a sequence of studies with real deadlines and deposits. Readiness is the filter: a project with site control and a serious deposit keeps its place, and a speculative one does not.

II.The honest math on the backlog

Nobody can give you a clean number, and anyone who does is guessing. At last public report, the capacity waiting in PJM's queue runs to many tens of gigawatts, and the large majority of it is solar, battery storage, or the two paired together. That is far more than will actually get built, because queues always hold projects that will later drop out.

What that means for Illinois specifically is harder to pin down. The queue mixes projects across every PJM state, and an in-service date listed today can slip by months or years as studies, upgrades, and financing play out. Treat any single date as a hope, not a promise, and watch whether a project advances from one study phase to the next.

III.Who decides, and who pays

Two names sit at the top. PJM runs the studies and the queue, and the Federal Energy Regulatory Commission, the federal agency that oversees the interstate grid, approves the rules PJM follows, including the shift to cluster review. When the process changes, it changes because FERC signed off.

Closer to home, ComEd owns the local wires a project actually connects to, the Illinois Power Agency runs the state programs like Illinois Shines that pay for much of the community solar, and the Illinois Commerce Commission oversees the utility. A project can clear PJM and still wait on a local hookup or a program slot, so the interconnection line is only one of several lines.

IV.Reading the queue yourself

You don't have to take a developer's word for it. PJM publishes its interconnection queue online, and you can filter it by state and county to find projects near you. Each entry carries a queue number, a fuel type, a size in megawatts, a study status, and a projected in-service date.

Read the columns with a little skepticism. A project showing active study status is further along than one that is merely requested, and a date that has not moved in a year may be stale. If you want to follow one project, note its queue number and check back each quarter to see whether its status actually changed.

V.Worth watching this month

1. Check PJM's interconnection queue page for whether the current transition cycle has posted new study results, which is routine but tells you the backlog is moving.

2. Watch for FERC filings on PJM's interconnection process, which matter because a rule change there resets timelines for every project in the line.

3. Track the Illinois Power Agency's Illinois Shines program for its next application window, since community solar needs a program slot as well as a grid connection.

4. Follow the Illinois Commerce Commission's open dockets for any ComEd grid-planning or distribution cases, which are usually technical but occasionally reshape what gets built where.