What Is the Grid Interconnection Queue?

Before any new power plant, solar farm, wind installation, or battery storage system can deliver electricity to consumers, it must connect to the existing transmission grid. The process of establishing that connection is called interconnection. Every project must submit a request to the regional transmission operator, which then conducts engineering studies to determine how the new project will affect grid reliability, what transmission upgrades might be needed, and how much those upgrades will cost.

As of late 2024, approximately 10,300 projects representing over 1,400 gigawatts of generation capacity and 890 gigawatts of energy storage were actively sitting in US interconnection queues. That combined capacity is more than twice the installed capacity of the entire existing US power plant fleet.

Why the Queue Has Become a Bottleneck

The interconnection queue was not designed to handle the volume of requests it now faces. A decade ago, new project applications were manageable, and studies could be completed in months. Today, the median time from submitting an interconnection request to reaching commercial operation has stretched to over four years, up from less than two years for projects built between 2000 and 2007.

Several factors have converged to create the backlog. The growth of renewable energy, accelerated by federal tax credits and state renewable portfolio standards, has driven a massive wave of new project proposals. At the same time, the US transmission system is aging and was not designed to accommodate thousands of distributed generation sources.

Speculative projects compound the problem. Many developers submit interconnection requests for projects that are not yet fully financed or permitted. Historical data shows that only about 13% to 19% of projects that enter the queue ever reach commercial operation. The rest are eventually withdrawn, but in the meantime, they consume study resources and delay projects that are ready to build.

How the Interconnection Study Process Works

The interconnection process typically involves three stages of engineering study. The first is a feasibility study, which provides a preliminary assessment of the project’s impact on the grid. The second is a system impact study, which conducts a more detailed analysis of reliability effects and identifies necessary transmission upgrades. The third is a facilities study, which provides detailed cost estimates for any required upgrades.

Each study can take months to complete, and projects often face restudies when earlier projects in the queue are withdrawn, changing the assumptions underlying later studies. The cost of transmission upgrades can also be a deal-breaker, sometimes reaching tens or hundreds of millions of dollars.

FERC Order 2023 and Reform Efforts

The Federal Energy Regulatory Commission recognized the interconnection crisis and issued Order 2023 in July 2023, the most comprehensive reform of generator interconnection procedures in two decades. The order shifted the process from a serial first-come, first-served approach to a cluster study model, where projects are grouped and studied together.

The order also introduced first-ready, first-served criteria, which prioritize projects that demonstrate financial and development readiness over those that are more speculative. Transmission providers face penalties for missing study deadlines, creating accountability for timely processing.

Individual regional operators have implemented their own additional reforms. PJM paused intake of new requests while clearing its backlog and expects to begin a reformed cycle-based process in 2026. MISO has implemented increased milestone payments and automatic withdrawal penalties.

Impact on Clean Energy Deployment

The interconnection queue backlog has real consequences for the energy transition. Hundreds of gigawatts of shovel-ready renewable energy and storage projects cannot deliver electricity to consumers because they are stuck in study processes. This delays the displacement of fossil fuel generation and increases electricity costs by constraining supply.

The backlog also creates competitive pressure. Large data center operators, frustrated by the timeline to add new grid-connected generation, are increasingly pursuing behind-the-meter solutions that bypass the interconnection queue entirely.

What Comes Next for Interconnection Reform

Clearing the interconnection backlog is widely recognized as one of the most critical challenges facing the US energy sector. The first-ready, first-served model should improve queue quality over time, but the existing backlog of thousands of projects will take years to process.

Longer-term solutions require investment in transmission infrastructure. Grid-enhancing technologies, such as dynamic line ratings and power flow control devices, can increase the capacity of existing transmission lines without building new ones. Expanded regional transmission planning can proactively build the infrastructure needed to unlock clean energy development. But all of these solutions take time, and the urgency of growing electricity demand means the window for action is narrowing.