Ontario electricity settlement
Global Adjustment value depends on customer class and settlement evidence.
Direct answer
Class A customers pay Global Adjustment using their Peak Demand Factor. Class B customers pay monthly consumption multiplied by the applicable Class B rate. A solar or storage result needs the customer's class, interval contribution, settlement periods, and current IESO rules.
· Economics guide
Code-native diagram
Global Adjustment period relationship
The base period establishes Peak Demand Factor before the later adjustment period applies it.
| Step | Evidence question |
|---|---|
| 1 | Base period |
| 2 | Top five provincial peaks |
| 3 | Peak Demand Factor |
| 4 | Adjustment period |
Conceptual geometry only. The official source basis and verification date are listed in the evidence rail on this page.
Class A and Class B use different calculations
IESO states that Class A charges use the customer's Peak Demand Factor. Class B charges use monthly consumption multiplied by the applicable Class B rate. A site cannot switch between those methods inside one worked result.
- OfficialPeak Demand Factor is the customer's percentage contribution during Ontario's top five peak hours in the base period.Verified 2026-07-17
The base period and adjustment period do different jobs
IESO defines the base period from 1 May through 30 April. The resulting Peak Demand Factor applies during the adjustment period from 1 July through 30 June. Operations during one window can therefore affect charges in a later window.
- OfficialThe base period runs from 1 May through 30 April, and the adjustment period runs from 1 July through 30 June.Verified 2026-07-17
- OfficialMonthly Class A Global Adjustment equals total monthly Global Adjustment costs multiplied by the customer's Peak Demand Factor.Verified 2026-07-17
Eligibility is demand and activity specific
IESO publishes automatic and opt-in demand bands, plus narrower access for certain manufacturing, industrial, and greenhouse customers. A customer's average monthly maximum hourly demand and applicable NAICS category need verification.
Enerwav does not infer Class A status from annual electricity consumption.
Solar and storage affect contribution only when timing aligns
Solar output or storage dispatch may reduce demand during a provincial peak, but prediction error, site operations, equipment limits, and the final IESO peak set control the result.
No Class A dollar example is published because the customer's Peak Demand Factor and monthly Global Adjustment total are not available.
Confirm Class A or Class B before modelling
IESO applies different Global Adjustment calculations to Class A and Class B customers. Class A uses the customer's Peak Demand Factor. Class B uses monthly consumption multiplied by the applicable Class B rate. Annual consumption alone does not establish the class, the payment method, or the value of a solar or storage action.
The account review should identify the market participant or local distribution company, the applicable eligibility process, historical class, opt-in or opt-out status, base-period records, adjustment-period records, and any facility changes that affect demand. A model that mixes Class A peak contribution with Class B volumetric settlement is not valid.
Apply the current demand bands and activity conditions
IESO states that customers with average monthly maximum hourly demand above the highest band qualify automatically unless they opt out. Customers in the middle band may opt in. A narrower lower band applies only to the listed manufacturing, industrial, and greenhouse activities when the demand and NAICS conditions are met.
The demand test uses average monthly maximum hourly demand, not one nameplate rating or annual energy total. The activity test also matters in the conditional lower band. Enerwav therefore does not infer eligibility from a postal address, business description, project size, or a single peak.
- OfficialCustomers with average monthly maximum hourly demand of more than 5 MW qualify automatically unless they opt out.Verified 2026-07-17
- OfficialCustomers with demand of more than 1 MW and no more than 5 MW can opt in to Class A.Verified 2026-07-17
- OfficialCustomers between 500 kW and 1 MW in certain manufacturing, industrial, and greenhouse activities may qualify when the listed NAICS and demand conditions are met.Verified 2026-07-17
Peak Demand Factor measures provincial coincidence
Peak Demand Factor is the customer's percentage contribution during Ontario's top five peak hours in the base period. A lower site peak on a day that does not become one of the final five provincial peaks does not change the factor. Conversely, an uncontrolled contribution during a final peak can affect the later adjustment period.
The operational problem is therefore prediction under uncertainty. Weather, provincial demand, embedded generation, market conditions, facility schedules, outages, maintenance, and controller availability can affect contribution. A strategy should define alert sources, operating authority, reserve, false-positive tolerance, and the cost of curtailing or shifting site activity.
Reconcile the base and adjustment periods
The base period runs from 1 May through 30 April. The resulting Peak Demand Factor applies in the adjustment period from 1 July through 30 June. The lag means a project commissioned partway through a base period may not have a full operating history before the later charges apply.
A financial model should state which base period produced the factor, which adjustment period receives it, and whether the customer's operations or facility boundary changed. The model should not apply a newly assumed factor to earlier bills or treat a historical factor as permanent. Each monthly Class A amount also depends on the total monthly Global Adjustment cost.
Separate solar coincidence from storage dispatch
Solar can reduce site demand during a provincial peak when production is available and consumed behind the meter at that hour. Cloud, season, array orientation, curtailment, outage, and site load can change the contribution. Annual generation does not establish performance during the final peak set.
Storage can respond to a forecast or dispatch signal within its power, energy, state-of-charge, reserve, and control limits. Repeated alerts can exhaust energy or create recharge conflicts. A resilience reserve can reduce energy available for Global Adjustment response. The operating plan should define which objective has priority and how missed events are recorded.
Keep the dollar result suppressed without customer settlement data
IESO's Class A formula requires the customer's Peak Demand Factor and the monthly Global Adjustment total. Neither value can be replaced by a generic percentage or a historical amount from another account. A hypothetical percentage can demonstrate multiplication, but it cannot represent a customer result.
Enerwav therefore explains the formula and periods without publishing a Class A dollar example. A project model should import verified account data, state whether the factor is observed or targeted, and show the specific months used. It should also preserve the possibility that the final provincial peak set differs from the events targeted during operations.
Keep the Ontario C-PPA framework separate
IESO's corporate PPA framework can matter to qualifying ICI participants, but it does not change the Class A eligibility evidence or Peak Demand Factor formula by itself. Contract settlement, generator eligibility, market participation, and the buyer's physical account remain separate review streams.
The customer should obtain current IESO and professional guidance before combining a C-PPA scenario with Global Adjustment forecasting.