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Explainer · Grid connection
How grid connection queues work
A storage project cannot operate until the grid operator agrees to connect it. Here is what happens between the request and the agreement, and why it now takes close to three years.
Every new power plant, battery or large load that wants to connect to the transmission network has to ask the grid operator first. The operator studies whether the network can carry the new flows, what has to be upgraded if it cannot, and who pays for the upgrades. The list of requests waiting for that process is the interconnection queue, usually just called the connection queue.
In our October storage outlook, developers named the connection queue as the main schedule constraint for 62% of the projects in our sample. This note explains what they are waiting for.
The steps
Rules differ between operators, but most now follow a cluster process with the same basic stages.
Request. The developer submits an application with a site, a point of connection, a requested capacity in megawatts and a deposit. Most operators now require proof of site control, which has cut the number of speculative requests but not removed them.
Cluster studies. Requests filed in the same window are studied together, usually in two phases. The first phase identifies overloads and rough upgrade costs. The second refines them after some projects withdraw. Each phase takes months, and each withdrawal can shift costs onto the projects that remain.
Facilities study. For projects that stay in, the operator and the local utility design the specific substation work and network upgrades and price them.
Interconnection agreement. The developer signs an agreement that sets the upgrades, the costs it will fund and a schedule. This is the point at which most developers treat a project as real enough to order long-lead equipment.
Construction and energization. The utility builds the network upgrades while the developer builds the project. The project is energized and tested before it reaches commercial operation.
Why storage waits
Storage projects go through the same studies as generators, and in some regions they are also studied as loads, because a battery charges as well as discharges. They tend to be proposed at substations that already have solar or wind nearby, where the network is often the most congested. And because storage is quick to build once approved, developers have filed a large number of requests in a short period, which lengthens every cluster they join.
None of this has much to do with batteries. A project with its battery order confirmed waits in the same cluster as one that has not chosen a supplier.
What the numbers look like
Midland Grid’s queue update for the third quarter is a useful reference because it reports storage separately. As of September 30, 2026, it had 214 active standalone storage requests totaling 41.6 GW, about a third of all queued capacity. Storage requests that signed an agreement in the previous twelve months had waited an average of 34 months from request to agreement, up from 27 months two years earlier.
Two cautions when comparing sources. Operators report queues in gigawatts of requested capacity, while project research, including ours, usually reports storage in gigawatt-hours of energy. A 100 MW, four-hour battery is 100 MW in a queue report and 400 MWh in a pipeline count. And a queue position is a request, not a commitment. Midland Grid reports that 31 storage requests withdrew in the past year.
What developers can control
Developers cannot speed up a cluster study. They can choose sites with spare network capacity, file complete applications, and plan around the agreement date rather than the announcement date. The developers in our sample who handle queue risk best treat the agreement as the start of the project schedule, not a step in the middle of it. After the agreement, the clock moves to equipment: transformers and high-voltage breakers can take longer to arrive than the battery itself.