NYISO Demand Curve Reset: Why the 2-Hour Battery Reference Raised Capacity

What NYISO changed for 2026-27

NYISO resets elements of the Installed Capacity (ICAP) demand curve each capability year [nyiso-icam]. For 2026-27 the reference unit shifted to a two-hour battery, replacing the prior reference resource economics [modo-nyc-capacity-2026] [rto-insider-nyiso-curve].

The demand curve answers: how expensive is the last megawatt of capacity needed to hit the reliability requirement? The reference unit defines the price at 100% of requirement when the market clears tight.

Reference point math that hit Zone J

Modo Energy summarized the NYC impact [modo-nyc-capacity-2026]:

NYC ICAP reference point rose from $14.6/kW-month to $17.8/kW-month.

Accreditation factor changes lifted the UCAP reference point at 100% of requirement about 41%, from $23.1/kW-month (winter) to $32.7/kW-month (summer).

When NYC cleared with no surplus at the reference point, May 2026 spot capacity hit $32.59/kW-month [modo-may-2026-reference].

This is structural pricing, not only a weather story. Even with flat peak load (+0.5% forecast move), requirement step-ups and derated supply pushed the city onto the steep part of the curve [modo-nyc-capacity-2026].

Why batteries as reference matter for buyers

Combustion turbines and two-hour batteries have different capital costs, O&M, and accreditation for ICAP [rto-insider-nyiso-curve]. Using a battery reference:

Raises or reshapes the reference price when the curve is rebuilt.

Changes accreditation factors for other resource types in the same auction (Modo noted NYC four-hour battery factors moved when CHPE entered [modo-chpe-july-2026]).

Signals NYISO's expectation that storage meets peak, which matches California's summer evening ramp but plays out through capacity in New York.

Cannabis cultivators rarely bid capacity into NYISO. They pay the curve through supplier ICAP pass-through.

How a 41% reference lift changed ICAP dollars on the same kW tag

Modo Energy tied the 2026-27 demand curve reset to a 41% lift in the UCAP reference point at 100% of requirement, from $23.1/kW-month (winter framing) to $32.7/kW-month (summer framing) [modo-nyc-capacity-2026]. The ICAP reference point itself moved from $14.6/kW-month to $17.8/kW-month [modo-nyc-capacity-2026]. A cultivator whose ICAP tag stayed flat at 300 kW still saw capacity cost jump because the price at requirement moved, not because the facility grew.

Curve version	UCAP at requirement	Monthly on 300 kW	Four-month capability period
Prior 2025-26 summer ref (illustrative tight clear)	~$23.1	$6,930	$27,720
2026-27 after battery reference	$32.7	$9,810	$39,240
Difference		+$2,880/mo	+$11,520

At 800,000 kWh over four months, the incremental ICAP alone adds about 1.4 ¢/kWh (($11,520 ÷ 800,000) × 100). Energy quotes moving 0.5 ¢/kWh can hide a curve-driven capacity step [modo-may-2026-reference].

Suppliers quoting fixed all-in rates before May 1, 2026 may have built older curve assumptions. Ask for a restatement using the $32.59/kW-month May clear [modo-may-2026-reference]. Floating ICAP contracts repriced automatically; fixed contracts with narrow capacity bands may trigger change-in-law clauses. RTO Insider noted the reference unit shift reflects NYISO's expectation that shorter-duration storage sets marginal capacity cost when the system is tight [rto-insider-nyiso-curve].

When CHPE qualified in July, Modo reported NYC UCAP fell to $12.41/kW-month [modo-chpe-july-2026]. That drop came from supply entering the stack, not from reversing the curve reset. Operators who budget only off July forward may understate May through June exposure already billed at the reference point.

From reference price to supply quote

Suppliers serving New York commercial choice customers often quote:

Fixed $/kWh with ICAP capped or excluded.

Fixed $/kWh all-in including assumed ICAP.

Monthly ICAP pass-through at NYISO spot clear.

Block energy + floating ICAP.

When the demand curve reset lifts the reference point 41% [modo-nyc-capacity-2026], all-in fixed quotes for Zone J need higher $/kWh unless the supplier absorbs margin. Many pass the increase through within one capability period.

Worked impact on a Brooklyn facility (illustrative)

Assume 280 kW ICAP obligation, 750,000 kWh per capability period (four months).

ICAP price	Monthly ICAP	ICAP ¢/kWh (smoothed)
Winter surplus ~$6/kW-month [modo-nyc-capacity-2026]	$1,680	~0.9 ¢
Summer reference ~$32.6/kW-month [modo-may-2026-reference]	$9,128	~4.9 ¢

Energy and delivery add on top. A curve reset that lifts summer reference pricing can move total effective supply cost more than a 0.5 ¢/kWh energy swing.

Batteries on-site vs ICAP market

Some operators ask whether on-site battery storage avoids ICAP. Behind-the-meter batteries do not automatically reduce your retail ICAP obligation unless structured through a supplier or market program that counts them.

NYISO's reference shift favors storage in the wholesale capacity stack. A cultivator battery shaving delivery demand may save Con Edison kW charges without touching ICAP unless enrolled in a market-facing program.

Do not conflate demand charge shaving with ICAP obligation reduction.

May 2026 reference price context

Modo reported NYC's overall reference price reached $244/MW-day in May 2026, up 105% year-over-year, with about 94% of the increase from the capacity component (Reference Capacity Price) [modo-may-2026-reference]. That component embeds demand curve results.

Winter 2025/26 energy spikes (ISO-NE and NY energy markets) are a separate line item from this capacity curve reset. New York operators must budget both.

Practical steps

Request supplier chart of ICAP pass-through May through August 2026 versus prior year.

Ask whether quotes use spot ICAP or reference price hedges.

If expanding in NY, compare Zone J to Long Island ($11/kW-month May clear [modo-may-2026-reference]) and upstate (~$8/kW-month).

Track NYISO stakeholder filings on curve parameters for 2027-28 [nyiso-icam].

Read fixed vs index contracts before locking 36 months in Zone J after a curve reset year.

Looking forward

Phase two ISO-NE reforms toward seasonal capacity may echo NYISO's summer/winter split elsewhere [iso-ne-ferc-car]. NYISO already runs capability periods May 1 and November 1 [nyiso-icam]. The 2-hour battery reference is the direction of travel: shorter-duration accredited resources set the price when the system is tight.

Cultivators are price takers in that design. Your leverage is contract structure, location, and peak kW management on delivery tariffs, not rewriting the demand curve.

Why a cultivator battery shaves delivery but rarely ICAP

NYISO's reference unit shift to a two-hour battery raises the price when the market clears at requirement [rto-insider-nyiso-curve] [modo-nyc-capacity-2026]. Behind-the-meter batteries help the wholesale stack through market programs, but a cultivator battery wired for demand-charge reduction does not automatically lower retail ICAP obligation unless enrolled in a supplier or market structure that counts it [nyiso-icam] [modo-may-2026-reference].

Typical BTM use cases for grows:

Peak shave Con Edison kW during afternoon light flip. Saves delivery demand.

Shift kWh off high LMP hours. Saves energy line on index contracts.

Do not reduce ICAP tag unless a program explicitly ties storage to capacity obligation reduction [nyiso-icam].

Modo reported NYC's May 2026 reference price reached $244/MW-day, up 105% year-over-year, with about 94% of the increase from the capacity component [modo-may-2026-reference]. That jump came from curve mechanics and tight clears, not from a single cultivator's meter [modo-may-2026-reference]. When CHPE offered capacity in July, UCAP fell to $12.41/kW-month because supply entered, not because the curve reset reversed [modo-chpe-july-2026].

If you evaluate on-site battery storage, model payback on delivery and energy savings first. Treat ICAP reduction as upside only if your supplier documents it in writing [rto-insider-nyiso-curve]. Zone J operators comparing Long Island ($11/kW-month May clear) to NYC ($32.6/kW-month) should weigh location before CapEx on storage that only shaves delivery [modo-may-2026-reference].

Accreditation factor changes ripple beyond batteries

RTO Insider reported NYISO rebuilt the demand curve around a two-hour battery reference unit instead of legacy combustion turbine economics [rto-insider-nyiso-curve]. Modo noted NYC four-hour battery accreditation factors moved when CHPE entered the capacity stack [modo-chpe-july-2026]. Cultivators do not bid accreditation, but they pay the cleared price that accreditation math produces [nyiso-icam].

When surplus is thin, the market clears at the reference point tied to the new curve [modo-nyc-capacity-2026]. That is why NYC hit $32.59/kW-month with only 0.5% peak load growth forecast [modo-nyc-capacity-2026]. Supply-side derates and requirement step-ups mattered more than cultivation load [modo-may-2026-reference].

For procurement, ask suppliers three numbers before May 1 capability reset [nyiso-icam]: assumed ICAP tag in kW, assumed UCAP $/kW-month, and whether true-ups use spot monthly auction or reference price hedge [modo-may-2026-reference]. Mismatch on any one input makes cross-supplier quotes incomparable [rto-insider-nyiso-curve].

Rest-of-state operators still use the updated 2026-27 curve even when absolute prices clear lower than Zone J [modo-nyc-capacity-2026]. A Hudson Valley grow with 320 kW ICAP at $8/kW-month pays $2,560 per month in capacity [modo-nyc-capacity-2026]. The same tag in Zone J at $32.59/kW-month pays $10,429 [modo-may-2026-reference]. Reference unit economics changed for the whole NYISO footprint; only locational tightness sets how close you land to the $32.7/kW-month summer reference at requirement [modo-nyc-capacity-2026] [rto-insider-nyiso-curve].

Read fixed versus index contracts before locking 36 months in Zone J after a curve reset year [modo-may-2026-reference]. Suppliers may shorten fixed tenors when reference prices move 41% in one capability cycle [modo-nyc-capacity-2026]. Track NYISO stakeholder filings on 2027-28 curve parameters on the ICAM page [nyiso-icam].

Winter 2025/26 energy spikes in ISO-NE and New York were separate from this capacity curve reset [modo-may-2026-reference]. Budget both energy and ICAP lines in downstate pro formas [nyiso-icam] [modo-chpe-july-2026].