The Independent System Operator for New England (ISO-NE) presented detailed proposals on September 15 to address Federal Energy Regulatory Commission (FERC) mandates regarding large electricity consumers and regional transmission planning. At the NEPOOL Transmission Committee meeting in Massachusetts, ISO-NE outlined expanded requirements for new loads of 50 megawatts or more, requiring them to fund their own interconnection capacity. The organization also announced it has resumed work on complying with FERC Order 1920 after a pause dedicated to longer-term transmission planning.
What it means
The proposed large load rules define qualifying customers as commercial or industrial entities at a single site with a gross peak demand of at least 50 MW, interconnecting above 60 kV. The proposal excludes energy storage, municipal services such as hospitals and water treatment plants, transportation hubs like airports, and campus facilities lacking dedicated loads over 1 MW. Electric vehicle charging complexes remain subject to the large load definition. Developers must pay a $50,000 application fee, a $150,000 study deposit, and a commercial readiness deposit of $10,000 per megawatt. System impact and facilities studies are capped at 90 days each, with the total process from application to transmission service agreement taking approximately one year. ISO-NE plans to vote on the proposal and file it under Section 205 of the Federal Power Act in mid-November, with supporting rules slated for 2027.
Transmission owners will implement cost recovery mechanisms to ensure large loads do not raise rates for other customers. Large load customers will pay at least the Regional Network Service rate; if payments fail to offset transmission impacts, they will cover additional costs. Three new service types are planned: firm contract demand, non-firm contract demand, and interim contract demand. Non-firm resources may avoid thermal upgrades through redispatch but remain liable for voltage or stability issues. ISO-NE will publish queue data including peak demand, location, and status.
ISO-NE has restarted compliance efforts for Order 1920, which requires regional and interregional transmission planning. FERC granted an extension, moving filing deadlines to mid-June 2027. States must agree on cost allocation methodology by February 17. ISO-NE proposes replacing the Order 1000 Public Policy Transmission Process with a “Future Scenario Planning” (FSP) framework using a construction bid model similar to those used by CAISO and MISO, rather than the current sponsorship model. FSP projects must demonstrate a benefit-to-cost ratio of at least 1.25. The recent Longer-term Transmission Planning (LTTP) procurement selected an Eversource and Avangrid joint proposal to reduce constraints in Maine after eliminating four technically deficient bids from six received. Competitive components without proposals will be assigned to incumbent transmission owners.
Key facts
- Large load threshold: 50 MW gross peak demand at a single site, interconnecting above 60 kV
- Exclusions: Energy storage, municipal services, transportation complexes, campus facilities under 1 MW dedicated load
- Fees: $50,000 application fee, $150,000 study deposit, $10,000/MW commercial readiness deposit
- Study timeline: 90 days for system impact and facilities studies; ~1 year total to service agreement
- New service types: Firm contract demand, non-firm contract demand, interim contract demand
- Order 1920 deadline: Regional/interregional planning filings due mid-June 2027
- Cost allocation deadline: States must agree by February 17
- FSP benefit-to-cost ratio: Minimum 1.25 required for project eligibility
Source: ISO-NE NEPOOL Transmission Committee meeting materials and summary