ISO-NE's interconnection queue holds 127 active generator projects totaling 14,541 MW. Less than 5,000 MW is likely to get built by 2029. Just 57 projects, 5,952 MW at nameplate, have executed interconnection agreements (IAs) and target commercial operation by 2029. But that nameplate figure overstates expected build. Build-through rates by technology, detailed below, cut the realistic outcome by 26% to 4,395 MW of expected build, 97% of it wind, solar, storage, or hydro.

State policy explains what projects enter the queue and where, whether through offshore wind state contracts, Massachusetts batteries earning Clean Peak Energy Certificates (CPECs), or solar dependent on RPS carve-outs.

Applying historical derating with project-specific overrides to the active pipeline with IAs, we have an expected build of 1,793 MW BESS, 1,741 MW offshore wind, 643 MW solar, and 103 MW onshore wind through 2029.

Key takeaways

• 57 projects and 5,952 MW nameplate have an executed IA and target 2029. Build-through rates cut expected capacity of batteries from 2,233 to 1,793 MW and solar from 1,162 to 643 MW.
• Offshore wind (2,295 MW, three projects) and batteries dominate the projects with IAs.
• Massachusetts batteries earn additional revenue through CPECs, leading to 76% of committed battery capacity in ISO-NE landing there.
• ISO-NE replaced its serial queue in October 2025, transitioning to a cluster study approach to the queue where projects are processed simultaneously.

59 projects have IAs, but agreement does not guarantee construction

ISO-NE's interconnection queue tracks a project's progress toward grid connection, including System Impact Study completion and proposed plan approval. But the IA is the defining gate. Projects without an executed IA will not build. Projects with an executed IA are what we call committed here, though an IA alone does not guarantee the project gets built.

Of 127 active generators, 59 have executed an IA. Two target commercial operation beyond 2029, leaving 57 committed through the planning horizon.