FERC Approved ISO-NE Prompt Capacity Market: What Suppliers Will Price Differently

What FERC approved on March 30, 2026

FERC accepted ISO New England's first batch of Capacity Auction Reforms (CAR) on March 30, 2026 [iso-ne-ferc-car]. The ISO worked on the project for more than two years with stakeholders [iso-ne-ferc-car]. Phase one includes two major changes: prompt auctions and a shorter deactivation process.

Phase two, still under stakeholder discussion with a FERC filing expected at end of 2026, would add separate winter and summer capacity auctions and update resource accreditation [iso-ne-ferc-car].

Prompt auctions in plain terms

Historically, ISO-NE capacity auctions cleared more than three years before the delivery period [iso-ne-ferc-car]. Under prompt auctions, the market will clear about one month before delivery [iso-ne-ferc-car].

ISO-NE lists three intended benefits [iso-ne-ferc-car]:

Better forecasts. Supply and demand projections closer to real time should improve auction parameters.

No phantom entry. Resources must be operational before selling capacity, so buyers get accredited MW that actually exist.

Administrative simplicity. Shorter schedules reduce overhead for the ISO and resource owners.

For a cannabis cultivator, the operational impact flows through supply rates, not through a separate cultivator tariff. Retail suppliers and utilities buy Forward Capacity Market (FCM) obligations and embed or pass through those costs.

Deactivation: four years down to one

Resources exiting the market previously gave four years' notice [iso-ne-ferc-car]. The approved reform shortens that to one year, with continued review for reliability and market manipulation concerns [iso-ne-ferc-car].

Faster exits can tighten capacity if retirements accelerate. Prompt auctions may price that risk closer to the delivery month rather than years in advance. Suppliers writing multi-year fixed contracts must decide how much deactivation risk they absorb versus pass through.

How this differs from PJM and NYISO

PJM still runs annual RPM auctions roughly one year forward (returning toward three-year forward in later cycles). NYISO runs monthly and seasonal capacity markets with capability period resets May 1 and November 1.

ISO-NE's prompt design moves it toward near-term capacity pricing similar in spirit to NYISO's monthly spot clears but through a structured FCM auction one month ahead [iso-ne-ferc-car]. Multi-state operators cannot assume one hedging playbook across RTOs.

What three-year-forward FCM added to a Massachusetts supply stack before 2028

Before prompt auctions, ISO-NE cleared Forward Capacity Market obligations roughly three years ahead [iso-ne-ferc-car]. A supplier signing a 36-month fixed contract in 2023 could embed FCM costs known from auctions run in 2022 through 2024 for delivery years 2025 through 2027. Cultivators saw capacity as a slow-moving line item that changed at multi-year boundaries, not monthly.

Worked stack for supply-side capacity only (illustrative; FCM clearing prices vary by zone and auction):

Item	Value
Facility peak	350 kW
FCM obligation (assumed)	0.35 MW
Blended FCM price	$3.50/kW-month (illustrative pre-reform average input)
Annual FCM cost	350 × $3.50 × 12 = $14,700
Annual kWh	1,400,000
FCM-only adder	1.05 ¢/kWh

Prompt auctions shift discovery to one month before delivery [iso-ne-ferc-car]. Suppliers who cannot hedge FCM three years out may shorten fixed tenors or widen pass-through bands. A cultivator renewing in 2027 for a term crossing 2028 should ask: does this quote fix FCM at the last prompt clear, cap it, or float it monthly? The energy rate alone is not the comparison.

Compare to winter 2025/26 energy volatility: FCM is capacity; LMP is energy [iso-ne-winter-recap]. A contract fixing energy through 2027 but passing FCM after prompt reform leaves half the stack exposed. Phase two may split winter and summer FCM auctions [iso-ne-ferc-car], which could align with cultivator seasonality if summer HVAC peaks drive your kWh but winter gas spikes drive your energy line.

Supplier pricing behavior to expect

Retail energy suppliers hedge capacity when they sell fixed rates. Under three-year-forward FCM, a 36-month fixed quote could lock capacity assumptions early. Under prompt auctions, suppliers may:

Shorten fixed-price tenors they offer without capacity risk premiums.

Increase index capacity pass-through on commercial contracts.

Add monthly true-ups tied to FCM clearing results starting 2028.

Charge wider margins to cover auction volatility they cannot hedge cheaply.

Cannabis loads with high kWh and moderate kW are still attractive customers, but low load factor makes capacity-heavy quotes expensive. Suppliers may prefer pass-through after reforms.

What cultivators should do before 2028

Read FCM language in current contracts. Search for "Forward Capacity Market," "FCM," "ISO-NE capacity," and "pass-through."

Ask suppliers for their 2028 transition plan. Reputable suppliers should publish a memo on how prompt auctions affect fixed offers.

Separate delivery from supply when budgeting. Massachusetts demand charges remain utility-side. FCM is supply-side. Do not conflate them in ROI models for LED retrofits.

Watch phase two filings. Separate winter and summer auctions could align with cultivator seasonality: high HVAC summer kWh versus winter gas-linked energy spikes [iso-ne-ferc-car].

Worked comparison (illustrative)

Assume 400 kW peak, 1.6 million kWh/year, Massachusetts, supply only.

Contract type	Pre-2028 behavior	Post-2028 prompt risk
Fixed all-in 24 mo	Supplier hedges FCM years ahead	Supplier may shorten fix or raise margin
Index energy + pass-through FCM	FCM trued up annually	FCM may true up monthly
Utility basic service	Periodic procurement	Regulator-set timing; lag may increase

Numbers depend on your supplier, not ISO-NE tariff tables. The table shows mechanism, not dollars.

Coordination with winter energy lessons

The coldest winter in 20 years stressed energy markets in 2025/26 [iso-ne-winter-recap]. Prompt capacity reforms address capacity timing starting 2028 [iso-ne-car-factsheet]. New England growers need both sides of the stack:

Winter index energy exposure (LMP volatility).

Future prompt FCM exposure (capacity volatility).

A fixed contract that only caps energy but passes FCM will not feel "fixed" after 2028.

Confirm with advisors

FERC acceptance is not the final word on every detail. Phase two filings may change winter/summer structure [iso-ne-ferc-car]. Confirm current CAR implementation dates with your supplier and the ISO-NE CAR fact sheet before signing contracts that cross 2028.

Transition timeline cultivators should pin on the wall

ISO-NE's first CAR batch took effect with FERC acceptance March 30, 2026 [iso-ne-ferc-car]. The first prompt auction under the new framework is planned for 2028 [iso-ne-ferc-car] [iso-ne-car-factsheet]. Between now and then, forward capacity market prices still reflect the prior three-year-forward design for delivery years already cleared [iso-ne-ferc-car].

Period	Capacity market behavior	Cultivator action
2026-2027	Prior forward clears still govern active delivery years [iso-ne-ferc-car]	Read FCM pass-through on renewals
2028 first prompt auction	Clears ~1 month before delivery [iso-ne-ferc-car]	Avoid assuming 36-month fixed includes FCM
Phase two (filed end 2026)	Possible split winter/summer FCM [iso-ne-ferc-car]	Watch stakeholder filings

Deactivation notice shortening from four years to one year means retirements can tighten capacity faster than under the old rules [iso-ne-ferc-car]. Prompt auctions price that risk closer to delivery [iso-ne-ferc-car]. Suppliers who once hedged FCM years ahead may shorten fixed tenors or widen pass-through bands [iso-ne-car-factsheet].

Connecticut and Massachusetts cultivators on the same ISO-NE footprint face identical FCM mechanics but different utility delivery tariffs [iso-ne-ferc-car]. When requesting quotes, attach a redlined contract section showing FCM treatment and ask: "If prompt auction clearing rises 15% month-over-month in summer 2028, who pays?" The answer separates true fixed offers from energy-only fixes [iso-ne-car-factsheet].

Winter 2025/26 energy volatility was an LMP story, not an FCM timing story [iso-ne-winter-recap]. Post-2028, you may face both gas-linked energy spikes and month-to-month FCM pass-through unless your contract caps both [iso-ne-ferc-car].

Contract red flags to search before 2028

ISO-NE's CAR fact sheet lists prompt auctions clearing about one month before delivery and deactivation notice shortened to one year [iso-ne-car-factsheet] [iso-ne-ferc-car]. Search your supply PDF for these phrases:

"FCM pass-through at ISO clearing price."

"Capacity adjusted monthly per Forward Capacity Market."

"Change in law includes ISO-NE market rule revisions."

"Fixed energy; capacity floats."

If two or more appear, assume post-2028 volatility lands on your invoice unless renegotiated [iso-ne-ferc-car]. Cultivators renewing in late 2027 for terms crossing 2028 should attach an exhibit: FCM capped at $X/kW-month or indexed to last prompt auction only [iso-ne-car-factsheet].

Phase two may add separate winter and summer FCM auctions with updated resource accreditation [iso-ne-ferc-car]. High summer kWh cultivators could see seasonal FCM mirror operational seasonality, but winter gas spikes would remain an energy problem on index contracts [iso-ne-winter-recap] [iso-ne-ferc-car]. Budget both stacks in ROI models for LED and HVAC projects rather than treating capacity as frozen [iso-ne-car-factsheet].

FERC accepted the first CAR batch March 30, 2026 after more than two years of ISO-NE stakeholder work [iso-ne-ferc-car]. Connecticut cultivators on Eversource and Massachusetts sites on National Grid face identical FCM timing changes even when delivery rates differ [iso-ne-car-factsheet]. Ask each supplier for a written 2028 transition memo before you sign a term that crosses the prompt auction start [iso-ne-ferc-car]. Resources exiting the market now give one year notice instead of four, which can tighten capacity faster than under the old rules [iso-ne-ferc-car].