ISO-NE files proposal with FERC to address ‘large loads’

Proposed processes related to “large loads” like data centers are designed to preserve the reliability of the regional bulk power system and avoid shifting costs to consumers.

ISO New England, the New England Power Pool, and the Participating Transmission Owners Administrative Committee jointly filed the proposal with the Federal Energy Regulatory Commission (FERC) this week.

Under the proposal, the ISO would assess the system impact of proposed large loads through a clearly defined application and study process to be implemented June 1, 2027.

The proposal creates three ways in which transmission customers may request transmission service on behalf of large loads:

Firm contract demand service gives the customer the same priority as all other firm loads. But it requires investment in the form of new capacity and upgrades to the transmission network to support the large load. Under the “bring your own new capacity” requirement, demand from the large load must be matched by new capacity supply.

Interim contract demand service is a non-firm service available for customers working to meet the requirements for firm service.

Non-firm contract demand service is a permanent service option that does not require designation of new capacity supply and may require less extensive network upgrades. It is designed for customers with flexible large loads willing to reduce electricity consumption under certain conditions.

The ISO would “re-dispatch” non-firm and interim contract demand service customers anytime energy prices in their area reach $250 per megawatt-hour (MWh). Re-dispatching requires the customer to either reduce consumption or increase eligible generation.

Currently the region crosses the $250/MWh price threshold in only about 1% of hours. Re-dispatching at this price ensures the non-firm customer is instructed to reduce demand prior to reliability risks posed by the customer’s lower level of network upgrades and lack of capacity supply.

The proposal also excludes non-firm and interim contract demand service from the calculation used to set the region’s installed capacity requirement (ICR) and related values. ICR represents how much electricity-generating and demand-reducing capability must be procured through the region’s capacity market.

Stakeholder discussions will continue in 2027 on the “bring your own new capacity” requirement. More detailed information is available in the ISO’s Large Loads Integration Proposal Information Summary.