Resolution
Independent Electricity System Operator; Hydro One Networks Inc.climateMaintained recordCurrent
What Ontario's connection assessments actually establish: the assessed station quantities behind the province's largest new industrial loads, the capacities the planning record publishes, and the reconciliations the process itself performs
The engineering layer of Ontario's connection process: final System Impact Assessment reports for the province's flagship new loads (the Windsor battery plant connection, the St. Thomas plant's new station, the Algoma Steel electric-arc-furnace staging, a Toronto data centre, the existing Dofasco station), the planning record's published local capacities (a shared station capacity with two named claimants; a circuit pair assessed across two vintages), and the issuer's own published reconciliations of firm and potential load against total capability. Every quantity is the issuer's own stated figure, quoted from the archived document; nothing is summed, allocated, or inferred.
A Resolution record holds one institution's own published figures for a single, specific quantity — a projection, an estimate, or a measured record — across every vintage in which that institution restated it. Each time an issuer publishes a new budget, report, or release, an earlier figure does not disappear from the record; it is preserved exactly as it was first published, dated and cited, alongside the newer one. What is a Resolution record? →
Maintained record. This lineage preserves an official record version by version — observations, estimates, or benchmarks its issuer restated over time. It projects nothing, so no settlement is pending; where a figure can still be revised, the page says so. How the numbers moved between versions is the evidence this lineage exists to keep.
The lineage
| Vintage | Issuer | Published | Position | Source |
|---|---|---|---|---|
| Final Report of 2023-07-10, captured 2026-08-03 | Independent Electricity System Operator | 2023-07-10 | current | Source → · accessed 2026-08-03 |
| Final Report of 2023-04-21, captured 2026-08-03 | Independent Electricity System Operator | 2023-04-21 | current | Source → · accessed 2026-08-03 |
| Final Report of 2024-06-12, captured 2026-08-03 | Independent Electricity System Operator | 2024-06-12 | current | Source → · accessed 2026-08-03 |
| Final Report of 2025-06-12, captured 2026-08-03 | Independent Electricity System Operator | 2025-06-12 | current | Source → · accessed 2026-08-03 |
| Final Report of 2024-10-16, captured 2026-08-03 | Independent Electricity System Operator | 2024-10-16 | current | Source → · accessed 2026-08-03 |
| Final Report of 2021-06-10, captured 2026-08-03 | Independent Electricity System Operator | 2021-06-10 | current | Source → · accessed 2026-08-03 |
| Final Report of 2019-09-12, captured 2026-08-03 — superseded on the aggregate-load finding by the 2020 addendum | Independent Electricity System Operator | 2019-09-12 | superseded | Source → · accessed 2026-08-03 |
| Addendum of 2020-11-17, captured 2026-08-03 — the governing vintage for the aggregate-load finding | Independent Electricity System Operator | 2020-11-17 | current | Source → · accessed 2026-08-03 |
| Report of 2024-04-18, captured 2026-08-03 | Independent Electricity System Operator | 2024-04-18 | current | Source → · accessed 2026-08-03 |
| Report of 2020-07-17, captured 2026-08-03 | Hydro One Networks Inc. | 2020-07-17 | current | Source → · accessed 2026-08-03 |
| Report of 2024-12-18, captured 2026-08-03 | Independent Electricity System Operator | 2024-12-18 | current | Source → · accessed 2026-08-03 |
| Final Addendum Report of 2025-06-30, captured 2026-08-04 | Independent Electricity System Operator | 2025-06-30 | superseded | Source → · accessed 2026-08-04 |
| Final Addendum 2 Report of 2026-02-04, captured 2026-08-04 — the governing vintage for the three-station requirement | Independent Electricity System Operator | 2026-02-04 | current | Source → · accessed 2026-08-04 |
| Vintage | Period | Value | Role | Assurance | Basis |
|---|---|---|---|---|---|
| Final Report of 2023-07-10, captured 2026-08-03 | Final connection assessment of 2023-07-10 — the assessed station maximum for the Windsor battery-plant station (CAA 2022-726) | 150.0 MW | institutional estimate | — | — |
| Final Report of 2023-04-21, captured 2026-08-03 | Final connection assessment of 2023-04-21 — Algoma Steel EAF Stage 1 (CAA 2021-694/695) | 140.0 MW | institutional estimate | — | — |
| Final Report of 2024-06-12, captured 2026-08-03 | Final connection assessment of 2024-06-12 — Algoma Steel EAF Stage 2B (CAA 2023-768) | 250.0 MW | institutional estimate | — | — |
| Final Report of 2024-06-12, captured 2026-08-03 | Final connection assessment of 2024-06-12 — the regional interface transfer limit stated in the Stage 2B assessment | 700.0 MW | institutional estimate | — | — |
| Final Report of 2025-06-12, captured 2026-08-03 | Final connection assessment of 2025-06-12 — Algoma Steel EAF Stage 3, the facility's full assessed level (CAA 2024-787) | 300.0 MW | institutional estimate | — | — |
| Final Report of 2024-10-16, captured 2026-08-03 | Final connection assessment of 2024-10-16 — the Toronto data centre's ultimate load (CAA 2024-795) | 80.0 MW | institutional estimate | — | — |
| Final Report of 2021-06-10, captured 2026-08-03 | Final connection assessment of 2021-06-10 — the existing Dofasco station's assessed one-time increase (CAA 2021-693) | 214.0 MW | institutional estimate | — | — |
| Final Report of 2019-09-12, captured 2026-08-03 — superseded on the aggregate-load finding by the 2020 addendum | Final connection assessment of 2019-09-12 — the stated load-security criterion for the Leamington-area circuit pair (CAA 2018-633) | 600.0 MW | institutional estimate | — | — |
| Final Report of 2019-09-12, captured 2026-08-03 — superseded on the aggregate-load finding by the 2020 addendum | Final connection assessment of 2019-09-12 — load along the corridor interruptible by configuration at the 2019 vintage (CAA 2018-633) | 567.0 MW | institutional estimate | — | — |
| Addendum of 2020-11-17, captured 2026-08-03 — the governing vintage for the aggregate-load finding | Addendum of 2020-11-17 — the restated interruptible-load aggregate at the 2020 vintage (CAA 2018-633 Addendum 1) | 608.0 MW | institutional estimate | — | — |
| Report of 2024-04-18, captured 2026-08-03 | Central-West Bulk Plan of 2024-04-18 — firm load in the London area, as the issuer states it | 620.0 MW | institutional estimate | — | — |
| Report of 2024-04-18, captured 2026-08-03 | Central-West Bulk Plan of 2024-04-18 — potential load beyond the firm load, as the issuer states it | 300.0 MW | institutional estimate | — | — |
| Report of 2024-04-18, captured 2026-08-03 | Central-West Bulk Plan of 2024-04-18 — the issuer's own stated total of firm plus potential load ('900 MW in total') | 900.0 MW | institutional estimate | — | — |
| Report of 2020-07-17, captured 2026-08-03 | Needs Assessment of 2020-07-17 — Port Arthur TS #1 station capacity after the low-voltage yard refurbishment, two named supplied parties, no published split | 59.0 MW | institutional estimate | — | — |
| Report of 2024-12-18, captured 2026-08-03 | Burlington to Nanticoke IRRP of 2024-12-18 — data-centre connection interest in the Caledonia-Norfolk subregion that the IRRP states its own forecast does not capture | 700.0–1,700.0 MW | institutional estimate | — | — |
| Final Addendum Report of 2025-06-30, captured 2026-08-04 | Final addendum of 2025-06-30 — the three-station total the applicant was required to stay below (CAA 2024-795) | 400.0 MW | institutional estimate | — | — |
| Final Addendum 2 Report of 2026-02-04, captured 2026-08-04 — the governing vintage for the three-station requirement | Final Addendum 2 of 2026-02-04 — the same three-station total, now a real-time switching threshold (CAA 2024-795) | 400.0 MW | institutional estimate | — | — |
| Final Addendum 2 Report of 2026-02-04, captured 2026-08-04 — the governing vintage for the three-station requirement | Final Addendum 2 of 2026-02-04 — the data centre's own ultimate load, restated unchanged (CAA 2024-795) | 80.0 MW | institutional estimate | — | — |
Movement between vintages
A record, not a ranking: this entry states what was published and how it compares to what followed. It never says who was right, which institution performed better, or grades a forecaster's competence.
| Comparison | Compared vintages | Movement | Basis |
|---|---|---|---|
| One circuit pair, two assessment vintages: the 2019 interruptible-load finding against the 2020 restatement | Final Report of 2019-09-12, captured 2026-08-03 — superseded on the aggregate-load finding by the 2020 addendum (institutional estimate 567.0 MW) vs. Addendum of 2020-11-17, captured 2026-08-03 — the governing vintage for the aggregate-load finding (institutional estimate 608.0 MW) | +41.0 MW | same issuer |
| One three-station limit, two assessment vintages: a build obligation replaced by a switching instruction | Final Addendum Report of 2025-06-30, captured 2026-08-04 (institutional estimate 400.0 MW) vs. Final Addendum 2 Report of 2026-02-04, captured 2026-08-04 — the governing vintage for the three-station requirement (institutional estimate 400.0 MW) | not comparable — The two figures are identical and the obligations attached to them are not. A numeric difference of zero would state that nothing changed between the vintages; what changed is what the number requires — from building capacity to stay below it, to switching a breaker when it is crossed. | same issuer |
Evidence qualifications (6)
- Every quantity here is a station, circuit, interface, or area figure from the connection and planning record. No document located states any plant's own operating demand, and no document states that a plant is its station's only load. Station quantities are never restated here as plant demand.
- The Algoma stages are successive assessed levels of one facility: 140, then 250, then 300 MW. They nest; summing the stages would triple-count one claim, and no such sum appears anywhere in this record.
- Applicants of record are frequently transmitters or distributors. The named plants (NextStar, the St. Thomas plant, the Alliston project) are the register rows' project names, not necessarily the applicants; nothing here attributes an application's conduct to the named project's proponent.
- Assessment reports are posted for a minority of large applications (20 of the 67-member register population at the 2026-07-10 vintage). What is assessed but unposted — including every Active application above 400 MW — cannot be checked from the public record; the issuer states unposted reports are obtainable by email by CAA ID.
- The issuer's published reconciliations (the Leamington vintages; the Central-West firm-plus-potential sentence) are quoted as the issuer's own arithmetic. Countability performs no allocation, no headroom subtraction, and no sum on these quantities.
- The 400 MW figure in the TOR1 lineage is a combined total for three named stations and all the load behind them, including but not limited to the data centre. It is not the data centre's own demand, which the same reports state separately and unchanged at 80 MW. The forecast that crosses the threshold is in a confidential appendix and is not published anywhere located.
Latest source: What Ontario's connection assessments actually establish: the assessed station quantities behind the province's largest new industrial loads, the capacities the planning record publishes, and the reconciliations the process itself performs · accessed 2026-08-03
Related on this site
- Brief: Claims on the grid: what Ontario's connection record proves about its largest new loads — and why the register they sit in cannot be added up →
- Receipt: Evidence summary for Claims on the grid: what Ontario's connection record proves about its largest new loads — and why the register they sit in cannot be added up →
- Domain: Climate →
- More Resolution lineages →
- Sources & Method →
A record, not a ranking: this entry states what was published and how it compares to what followed. It never says who was right, which institution performed better, or grades a forecaster's competence.
This is the current public record for this lineage. See Work with Countability for a commissioned projection-resolution question.
Work with Countability