LEARN / GLOSSARY
Interconnection queue
The list of projects awaiting the impact studies required before they can connect to the transmission grid. It is an application list rather than a pipeline, and it covers generation only.
Definition
Transmission system operators require proposed power plants seeking to connect to the grid to undergo a series of impact studies before they can be built. Those studies establish what new transmission equipment or upgrades are needed and assign the cost. The lists of projects in that process are the interconnection queues.
How it is measured
Lawrence Berkeley National Laboratory compiles queue data annually from the seven ISOs and RTOs and roughly fifty non-ISO balancing areas, together representing about 98 percent of installed American generating capacity. At the end of 2025 more than 2,060 GW of generation and storage was actively seeking connection, and the median duration from request to commercial operation exceeded five years for projects built that year, against under two years for projects built between 2000 and 2007.
Measurement noteThe dataset covers generation requests only. It excludes load interconnection requests, distribution-connected projects and behind-the-meter projects. A factory or data center applying to connect as new load appears nowhere in the headline queue figures, which is a common source of confusion when the queue is cited as a measure of industrial siting delay.
Why the dictionary version is insufficient
Calling the queue a waiting list implies that everything in it is waiting to be built. Historically only about 13 percent of the capacity that submits a request reaches operation. Queue volume therefore describes applications rather than forthcoming supply, and reading it as a pipeline overstates by roughly a factor of eight.
Related terms
Firm power · Nameplate capacity · Capacity factor
Appears in
Why Reindustrialization Requires More Electricity
Read next
Why Reindustrialization Requires More Electricity
Sources
- Lawrence Berkeley National Laboratory, Queued Up: 2026 Edition. emp.lbl.gov
- Federal Energy Regulatory Commission, Order No. 2023. ferc.gov