LGIP: the pro forma rulebook for connecting a large generator
The standard procedures, filed in every open access transmission tariff, that govern how a generating facility larger than 20 MW requests and obtains interconnection.
The Large Generator Interconnection Procedures are the standard interconnection rulebook that FERC requires transmission providers to include in their open access transmission tariffs. They apply to generating facilities larger than 20 MW; smaller facilities use the small generator procedures.
The procedures set out each step: the content of an interconnection request, the entry requirements including site control and deposits, the study sequence, the timelines and the penalties for missing them, the withdrawal rules, and the tender of an interconnection agreement.
FERC revised the pro forma substantially in Order No. 2023, moving to a first-ready, first-served cluster study process, tightening commercial readiness requirements, and imposing study delay penalties on transmission providers. Regional tariffs implement the pro forma with variations that must be shown to be consistent with or superior to it, and those compliance filings are the reason interconnection reform is litigated region by region in separate dockets.
Questions
- What size threshold applies?
- The large generator procedures apply above 20 MW. At or below that threshold the small generator interconnection procedures apply.
- Can a region depart from the pro forma?
- Yes, on a showing that its variation is consistent with or superior to the pro forma. Those variations are filed and litigated in FERC dockets.
Sources
- 01
Improvements to Generator Interconnection Procedures and Agreements, Order No. 2023
Federal Energy Regulatory Commission · RM22-14-000 · retrieved 2026-08-09
- 02
Pro forma Large Generator Interconnection Procedures and Large Generator Interconnection Agreement
Federal Energy Regulatory Commission · pro-forma-LGIP-LGIA · retrieved 2026-08-09