Interconnection Cost Analysis in the PJM Territory

Electric transmission system operators (ISOs, RTOs, or utilities) require new large generators seeking to connect to the grid to undergo a series of impact studies before they can be built. This process establishes what new transmission equipment or upgrades may be needed before a project can connect to the system and assigns the costs of that equipment. Berkeley Lab has collected interconnection cost data from interconnection studies for the PJM Territory, representing nearly 86% of all new unique generators requesting interconnection from 2000 to 2022. Project-level cost summary data are available for download on this page.

We find:

• Average interconnection costs have grown as the number of interconnection requests have escalated
• Projects that have completed all required interconnection studies have the lowest cost compared to applicants still actively working through the interconnection process or those that have withdrawn.
• Broader network upgrade costs are the primary driver of recent cost increase.
• Potential interconnection costs for wind, storage, and solar are larger than for natural gas
• Larger generators have greater interconnection costs in absolute terms, but economies of scale exist on a per kW basis.
• Interconnection costs vary by location

Berkeley Lab will publish a series of short analytical papers of generator interconnection costs to the transmission system for MISO, PJM, SPP, ISO-NE and NYISO, which you can find at https://emp.lbl.gov/interconnection_costs.