Next: The next attended register capture, and examination of newly posted assessment references from cycle 2; engineering findings below remain dated to the first reading.
The August register has 71 qualifying large-load applications; six whole-register moves to Withdrawn and four to Complete describe status changes, not delivered power.
The answer
Between the IESO's July 10 and August 14, 2026 list vintages, the whole register grows from 2,044 to 2,062 records: 18 added and none removed. Under the same large-load rule -- load-class applications stating at least 75 MW, excluding sizes stated only in MVA -- membership rises from 67 to 71, with four entries and no exits. Across the whole register, 24 status strings change: 6 move to Withdrawn (four from Active and two from On-Hold), 4 move from Active to Complete, and 3 move from Complete back to Active. One of the 24 changes merely corrects 'Actice' to 'Active'. These are register states, not proof that six projects were cancelled or four projects now supply power. The issuer dates the newer list August 14; Countability captured it on September 2.
Engineering-evidence scope: the assessment readings below retain their August 4 evidence cutoff. Newly posted reference links in cycle 2 have not yet been read as engineering evidence, so this update makes no claim that all assessments are current.
First reading, register dated July 10, 2026 (preserved for comparison): Ontario's public connection register carries 67 large load applications -- each stating 75 megawatts or more -- at its 2026-07-10 vintage, spanning completed, active, on-hold, and withdrawn states. For the flagship projects, the engineering layer beneath the register states exact assessed quantities: 150 MW for the station supplying the Windsor battery plant, 331.2 MW for the new station supplying the St. Thomas plant, a staged rise -- 140, then 250, then 300 MW -- for Algoma Steel's electric-arc furnaces, and 80 MW for a Toronto data centre. But the register itself cannot be added up, for reasons its own fields prove: its size column has no stated definition and mixes increments with totals -- the St. Thomas project reads 420 MW in the register and 331.2 MW in its own final assessment, with no issuer reconciliation; the 67 applications mix 35 completed, 22 active, 5 on hold, and 5 withdrawn, eight of them already in service; applicant names are not normalized, so even counting who is asking requires judgment the register does not supply; and 47 of the 67 carry no posted assessment to check any figure against, including all four active applications above 400 MW. What the process does publish, it reconciles itself: on the Leamington-area circuits it re-measured its own aggregate vintage over vintage -- 608 MW of load interruptible under the studied contingency, instead of 567 -- and published its own conclusion against its own criteria both times. What it withholds is just as specific: no located document states any plant's own operating demand, only its station's assessed maximum, and no located document splits a shared station capacity between the users it names. The register also moves quietly, and one of its moves is now visible. A public web archive preserved the same feed as the issuer served it on 1 June 2026: there, the 431 MW application for the Honda Alliston project -- filed by Hydro One Networks Inc., not by Honda -- is recorded Active, and a second, separate Alliston application of 24 MW is recorded Complete with its assessment posted. In the vintage the issuer dates 10 July 2026 both are recorded Withdrawn, and both still read Committed 'Yes' -- which the issuer's own connection FAQ says is removed when an application is withdrawn. Only four of the register's 2,044 rows carry that combination, and two of them are these. No public document located states why either application was withdrawn.
What this means for the decision
Treat any single number offered as the total of Ontario's connection queue as unsound -- the register's own fields cannot support one. For any specific project, read its posted connection assessment rather than its register row; where the two differ, the difference is real and unreconciled. Read station quantities as connection maxima, not as the plant's demand. And date every claim to a register vintage: the register is overwritten in place, states change without notice, and the month-over-month record starts with this Brief's capture cadence.
The key uncertainty
Register sizes cannot be totalled into delivered capacity. The assessment evidence below remains dated to August 4; new cycle-2 reference links have not been re-adjudicated, so historical no-posted-assessment findings are not asserted for the August list. At the July 10 first-reading vintage, the unposted majority was the sharpest limit: 47 of 67 applications, including every active one above 400 MW, have no public assessment, so their stated sizes cannot be checked against any engineering document. On history, this reading is no longer confined to a single state -- a public web archive holds prior vintages of the same feed, which is how the withdrawals above became visible -- but that archive is captured irregularly by a third party, not on the issuer's schedule, so it supports specific comparisons rather than a continuous record. A continuous one begins with Countability's own successive captures.
What would settle it
The next attended register capture, and examination of newly posted assessment references from cycle 2; engineering findings below remain dated to the first reading.
Battery plants, steel furnaces, and data centres are usually discussed through announcements, and announcements carry no obligation to state what a project asks of the grid. The connection process does: before a large load connects, the system operator assesses it and states the quantity. That makes Ontario's public connection register and its posted assessments the only public layer where these claims become checkable numbers -- and it is easy to misread. The register's size column invites totalling into headline gigawatts; its own fields show why that arithmetic is unsound. And the register is overwritten in place: nothing preserves what it said last month unless someone captures it. This Brief states what the engineering record actually proves, what the register can and cannot say, what the process publishes and withholds, and what Countability watches from here, capture by capture.
Evidence reviewed through 2026-09-06 · 6 cited sources · 2 member Resolutions · 6 chapters
Resolution lineages behind this Brief: What Ontario's connection assessments actually establish: the assessed station quantities behind the province's largest… → · Ontario's public connection register: what the IESO's Application Status list states about large proposed loads,… →
Each attended monthly register capture supports a dated status reading. Engineering assessment updates require their own reference check and reading; the September 2 capture is incorporated here as a register-only comparison.
Chapter 1§
What changed in the next register
The newer register beside the first reading: total records, qualifying large loads and whole-register status changes, each on its stated population and vintage. A status change is not a delivered-power measurement.
| Period | Value | Role | Assurance | Basis |
|---|---|---|---|---|
| August 14, 2026 list vintage — records | 2,062.0 records | institutional estimate | — | Census of preserved feed; large-load membership, where applicable, requires load-class type and stated size at least 75 MW, excluding MVA-only records. |
| August 14, 2026 list vintage — population | 71.0 applications | institutional estimate | — | Census of preserved feed; large-load membership, where applicable, requires load-class type and stated size at least 75 MW, excluding MVA-only records. |
| Whole-register July 10 to August 14 change — withdrawals | 6.0 status transitions | institutional estimate | — | Count of the stated status transition between two preserved register feeds; whole-register scope, not the large-load subset. |
| Whole-register July 10 to August 14 change — completions | 4.0 status transitions | institutional estimate | — | Count of the stated status transition between two preserved register feeds; whole-register scope, not the large-load subset. |
| Whole-register July 10 to August 14 change — reversals | 3.0 status transitions | institutional estimate | — | Count of the stated status transition between two preserved register feeds; whole-register scope, not the large-load subset. |
The evidence behind this chapter: Ontario's public connection register: what the IESO's Application Status list states about large proposed loads,… →
Chapter 2§
First reading — What the engineering record proves
Historical evidence at the first-reading register and assessment cutoff. The assessed quantities behind Ontario's flagship new loads -- the figures the connection process, not the press release, states -- each quoted from its archived final assessment.
| Period | Value | Role | Assurance | Basis |
|---|---|---|---|---|
| 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 | — | The final System Impact Assessment's own figure ('150 MW in Windsor area (the “project”)'). A station maximum assessed for connection, not the plant's own… |
| Final connection assessment of 2025-09-19 — the assessed station maximum load for Centennial TS (CAA 2023-766) | 331.2 MW | institutional estimate | — | The final System Impact Assessment's own figure for the new station ('331.2 MW (the “project”)'), phased in two equal stages. A station maximum assessed for… |
| Final connection assessment of 2023-04-21 — Algoma Steel EAF Stage 1 (CAA 2021-694/695) | 140.0 MW | institutional estimate | — | The assessment's own Stage 1 figure: 140 MW of new load at the EAF customer transformer station. One stage of one facility; never summable with the later… |
| Final connection assessment of 2024-06-12 — Algoma Steel EAF Stage 2B (CAA 2023-768) | 250.0 MW | institutional estimate | — | The assessment's own Stage 2B figure ('250 MW at their 115 kV EAF Customer Transformer Station'): the facility's successive assessed level, containing Stage 1,… |
| 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 | — | The assessment's own Stage 3 figure ('300 MW at their 115 kV EAF Customer Transformer Station', December 2029). The register's three Size increments — 140,… |
| Final connection assessment of 2024-10-16 — the Toronto data centre's ultimate load (CAA 2024-795) | 80.0 MW | institutional estimate | — | The assessment's own figure ('80 MW with a power factor' as stated), phased 20/20/40 to the ultimate load. |
| Final connection assessment of 2021-06-10 — the existing Dofasco station's assessed one-time increase (CAA 2021-693) | 214.0 MW | institutional estimate | — | The assessment's own figure ('214 MW at its existing Dofasco' station): a 14 MW increase of the existing 200 MW connection. The separate 280 MW decarbonization… |
The evidence behind this chapter: What Ontario's connection assessments actually establish: the assessed station quantities behind the province's largest… →
Chapter 3§
First reading — The register the claims sit in
Historical evidence at the first-reading register and assessment cutoff. The public connection register counted from its own fields, under a stated rule -- who is in the large-load population, in what status, and how the register keeps its books.
| Period | Value | Role | Assurance | Basis |
|---|---|---|---|---|
| Register list vintage 2026-07-10 — every record in the feed | 2,044.0 records | institutional estimate | — | Derived from the archived feed bytes by Countability's committed register census, under the stated population rule; the Brief's release battery re-derives this… |
| Register list vintage 2026-07-10 — load-class applications with a stated Size of at least 75 MW | 67.0 applications | institutional estimate | — | Derived from the archived feed bytes by Countability's committed register census, under the stated population rule; the Brief's release battery re-derives this… |
| Register list vintage 2026-07-10 — population members whose assessment status reads Complete | 35.0 applications | institutional estimate | — | Derived from the archived feed bytes by Countability's committed register census, under the stated population rule; the Brief's release battery re-derives this… |
| Register list vintage 2026-07-10 — population members whose assessment status reads Active | 22.0 applications | institutional estimate | — | Derived from the archived feed bytes by Countability's committed register census, under the stated population rule; the Brief's release battery re-derives this… |
| Register list vintage 2026-07-10 — population members whose assessment status reads On-Hold | 5.0 applications | institutional estimate | — | Derived from the archived feed bytes by Countability's committed register census, under the stated population rule; the Brief's release battery re-derives this… |
| Register list vintage 2026-07-10 — population members whose assessment status reads Withdrawn | 5.0 applications | institutional estimate | — | Derived from the archived feed bytes by Countability's committed register census, under the stated population rule; the Brief's release battery re-derives this… |
| Register list vintage 2026-07-10 — population members whose proposed in-service field already reads In-Service | 8.0 applications | institutional estimate | — | Derived from the archived feed bytes by Countability's committed register census, under the stated population rule; the Brief's release battery re-derives this… |
| Register list vintage 2026-07-10 — load-class records excluded from the population because their Size is stated only in megavolt-amperes (at or above 75 MVA) | 15.0 applications | institutional estimate | — | Derived from the archived feed bytes by Countability's committed register census, under the stated population rule; the Brief's release battery re-derives this… |
| Register list vintage 2026-07-10 — distinct Applicant field spellings across the full register | 432.0 distinct applicant strings | institutional estimate | — | Derived from the archived feed bytes by Countability's committed register census, under the stated population rule; the Brief's release battery re-derives this… |
| Register list vintage 2026-07-10 — groups of applicant spellings that collapse together under a stated normalization | 25.0 spelling groups | institutional estimate | — | Derived from the archived feed bytes by Countability's committed register census, under the stated population rule; the Brief's release battery re-derives this… |
The evidence behind this chapter: Ontario's public connection register: what the IESO's Application Status list states about large proposed loads,… →
Chapter 4§
First reading — Why the register cannot be totalled
Historical evidence at the first-reading register and assessment cutoff. The register's own fields, against the engineering record beneath them: an undefined size column that mixes increments with totals, one project carrying two unreconciled figures, and stages that nest rather than add.
| Period | Value | Role | Assurance | Basis |
|---|---|---|---|---|
| Register list vintage 2026-07-10 — the Centennial TS register row's stated Size (CAA 2023-766) | 420.0 MW | institutional estimate | — | Size field of CAA 2023-766 ('Centennial TS: New Station', applicant Hydro One Networks Inc., status Complete). The same project's final connection assessment… |
| Register list vintage 2026-07-10 — the Dofasco decarbonization application's stated Size (CAA 2021-712), On-Hold, no posted assessment | 280.0 MW | institutional estimate | — | Size field of CAA 2021-712 ('Dofasco Bayfront CTS - Decarb Project', applicant ArcelorMittal Dofasco G.P., status On-Hold, no posted report link).… |
| Comparison | Movement | Convention |
|---|---|---|
| One project, two issuer surfaces: the Centennial TS register row against its own final connection assessment | not comparable — The register's Size basis is unstated: holding 420 against the assessed 331.2 as a numeric difference would assert a shared basis no issuer document establishes. The unreconciled divergence between… | Same issuer, same project, two published figures: the register row states 420 MW with no definition of Size; the final assessment states an assessed station maximum of 331.2 MW, phased 165.6 plus 165.6. The gap is 88.8… |
Chapter 5§
First reading — What the process publishes -- and what it withholds
Historical evidence at the first-reading register and assessment cutoff. The connection process performs and publishes its own reconciliations, vintage over vintage — and the same process withholds the two quantities a reader most wants: any plant's own demand, and any split of a shared capacity between named users. One lineage shows both halves at once, across three dated assessments: a published limit whose obligation changed, and the forecast behind it kept confidential.
| Period | Value | Role | Assurance | Basis |
|---|---|---|---|---|
| Register list vintage 2026-07-10 — population members carrying at least one posted assessment-report link | 20.0 applications | institutional estimate | — | Derived from the archived feed bytes by Countability's committed register census, under the stated population rule; the Brief's release battery re-derives this… |
| Register list vintage 2026-07-10 — population members carrying no posted assessment report | 47.0 applications | institutional estimate | — | Derived from the archived feed bytes by Countability's committed register census, under the stated population rule; the Brief's release battery re-derives this… |
| Register list vintage 2026-07-10 — the largest Active application (CAA 2025-833), no posted assessment | 707.0 MW | institutional estimate | — | Derived from the archived feed bytes by Countability's committed register census, under the stated population rule; the Brief's release battery re-derives this… |
| Register list vintage 2026-07-10 — the second-largest Active application (CAA 2025-848), no posted assessment | 695.0 MW | institutional estimate | — | Derived from the archived feed bytes by Countability's committed register census, under the stated population rule; the Brief's release battery re-derives this… |
| Register list vintage 2026-07-10 — the third-largest Active application (CAA 2025-863), no posted assessment | 550.0 MW | institutional estimate | — | Derived from the archived feed bytes by Countability's committed register census, under the stated population rule; the Brief's release battery re-derives this… |
| Register list vintage 2026-07-10 — the fourth-largest Active application (CAA 2024-810), no posted assessment | 453.0 MW | institutional estimate | — | Derived from the archived feed bytes by Countability's committed register census, under the stated population rule; the Brief's release battery re-derives this… |
| 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 | — | The 2019 assessment's stated criterion: up to '600 MW of load' is allowed to be interrupted by configuration with two transmission elements out of service,… |
| 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 | — | The 2019 assessment's own aggregate ('567 MW of load along' the corridor, interruptible by configuration under the studied contingency). The same report… |
| Addendum of 2020-11-17 — the restated interruptible-load aggregate at the 2020 vintage (CAA 2018-633 Addendum 1) | 608.0 MW | institutional estimate | — | The addendum's own restatement ('608 MW, instead of 567 MW') of the corridor's interruptible-load aggregate — above the stated 600 MW criterion level; the… |
| Final connection assessment of 2024-06-12 — the regional interface transfer limit stated in the Stage 2B assessment | 700.0 MW | institutional estimate | — | The assessment's own statement of the interface limit: '700 MW under all elements in-service' conditions. A published shared bound on the region's flows — the… |
| Central-West Bulk Plan of 2024-04-18 — firm load in the London area, as the issuer states it | 620.0 MW | institutional estimate | — | The bulk plan's own figure ('620 MW (690 MVA) within the London Area'). |
| Central-West Bulk Plan of 2024-04-18 — potential load beyond the firm load, as the issuer states it | 300.0 MW | institutional estimate | — | The bulk plan's own figure ('300 MW of Potential Load' beyond the firm load). |
| 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 | — | The issuer's own reconciliation, in one sentence: firm load plus potential load, '(i.e., 900 MW in total)', held against the area's supply capability. The sum… |
| 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 | — | The transmitter's own figure (the station 'capacity will revert back to 59MW' once the refurbishment completes) for a station supplying two named parties —… |
| 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 | — | institutional estimate | — | The IRRP's own stated range ('1,700 MW of data centre connections' at the top; the report states 700 to 1,700 MW of interest in the subregion), with the… |
| 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 | — | Energy+ MTS#1, Preston TS and Galt TS, combined: the addendum requires the applicant to build a new station 'in a timely manner so that the total load at… |
| 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 | — | Energy+ MTS#1, Preston TS and Galt TS, combined: the superseding addendum requires that a low-voltage tie breaker 'remains open when the forecasted total peak… |
| Final Addendum 2 of 2026-02-04 — the data centre's own ultimate load, restated unchanged (CAA 2024-795) | 80.0 MW | institutional estimate | — | The data centre's own load, restated by the newest assessment: 'The project will have an ultimate load of 80 MW with a power factor of 0.95'. The three-station… |
| Comparison | Movement | Convention |
|---|---|---|
| One circuit pair, two assessment vintages: the 2019 interruptible-load finding against the 2020 restatement | +41.0 MW | Same issuer, same instrument lineage, same circuit pair, two vintages: 567 MW of load interruptible by configuration (2019 final report — which itself concluded the load-restoration criteria were violated), then 608 MW… |
| One three-station limit, two assessment vintages: a build obligation replaced by a switching instruction | 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… | Same issuer, same connection application, same three stations, same stated figure of 400 MW — and a changed obligation. In June 2025 the requirement was to build a new station in time so the three-station total would… |
How much electricity does any of Ontario's flagship new plants actually draw?
What is missing: No located public document states any plant's own operating demand. Ontario's connection record states what a station is assessed to supply -- 150 MW at the Windsor battery-plant station, 331.2 MW at the new St. Thomas station -- and no located document states that a plant is its station's only load, or what share of the station's assessed maximum the plant itself uses. The one public document that does state a St. Thomas plant utility quantity is the city's wastewater master plan, and that figure is the municipal planner's own assumption, not the company's statement.
Consequence: Public discussion routinely reads station connection quantities as plant demand. The two are different quantities, and the gap between them is not publicly measurable for any of the register's flagship projects. Any claim of the form 'plant X uses Y megawatts' sourced to a connection document is overstated by construction.
When two users share one published station capacity in Ontario, who holds how much of it?
What is missing: No located Ontario document publishes a per-user split of a shared station capacity. The clearest instance is on the record: Hydro One's Northwest Ontario Needs Assessment states Port Arthur TS #1's capacity (59 MW after refurbishment) and names the two parties it supplies -- Hydro One Distribution and Synergy North -- but its forecast table carries a single combined row, and neither party's share is published anywhere located.
Consequence: Where a shared capacity is approaching its bound, the public record can show that it binds but not whom it binds first. Allocation questions -- whose growth the constraint stops -- are unanswerable from the public record at station grain.
Why can none of Ontario's largest active connection applications be checked against an engineering document?
What is missing: Of the 67 large load applications in the register's population at the 2026-07-10 vintage, 47 carry no posted assessment report -- including all four active applications above 400 MW (707, 695, 550, and 453 MW as the register states them). Posting is a strong tendency, not a rule: some on-hold and withdrawn applications do carry posted reports, so no status explains the boundary. The issuer states unposted final reports are obtainable by email, by application ID.
Consequence: The register's largest live claims are exactly the ones whose stated sizes cannot be checked against any public engineering document. For the northern interface the record bounds at 700 MW, the assessment that would establish a second large claimant's share would be produced by the very process whose posting practice withholds it — and for a live application it may still be in progress. Either way, the join is not public.
What would Ring of Fire mining loads require of Ontario's northern grid?
What is missing: No public document states how much electricity Ring of Fire mining development would draw. A transmission line toward the area is now a designated provincial priority: on 2026-01-28 Hydro One announced that Ontario had designated it to build the Greenstone Transmission Line, a single-circuit 230 kV line from the existing East-West Tie near Nipigon Bay, through Longlac Transformer Station, to a new switching station at or near Aroland First Nation, expected in service in 2032 — in the announcement the province's energy minister described it as 'delivering the energy backbone and infrastructure to unlock the Ring of Fire's vast mineral potential'. That announcement states no megawatt figure for any Ring of Fire load, and neither does the transmitter's own current regional planning cycle: the Northwest Region Needs Assessment of 2025-09-03 and the Scoping Assessment of September 2025 do not name the Ring of Fire at all, while describing the region's demands — 'such as mining operation, data centers, forestry companies and large industrial manufacturers' — as 'distinctive, urgent and ever evolving'.
Consequence: A line is being built toward the deposit and the load it would serve has never been publicly quantified. Public discussion of Ring of Fire development therefore proceeds with a construction commitment and an in-service year but no published engineering statement of the requirement: no load figure, no delivery point for mine demand, no constraint assessment. Any megawatt figure attached to Ring of Fire mining load in commentary has no public engineering source. The gap is now sharper than an absence of interest — the interest is designated, funded and dated, and the quantity is still missing.
How much load is actually forecast at the Ontario stations whose shared limit now governs a connection?
What is missing: The load forecast that drives a published shared-capacity requirement is not published. In the connection assessment for a Cambridge-area data centre, the system operator states that the applicant's updated forecast for three named stations is projected to exceed a stated 400 MW during the study period, and imposes a real-time switching requirement on that basis — while placing the forecast itself in a confidential appendix ("Table 1 of Appendix A (Confidential) shows the updated load forecast"). The assessments behind the finding are in a second confidential appendix. The threshold and the remedy are public; the quantity that crosses the threshold, and the year it crosses, are not.
Consequence: A reader can see that a shared limit is being reached and what the operator will do about it, but cannot see by how much, how soon, or how much of the growth belongs to which load. The same document shows why the distinction matters: the three-station total is a different quantity from the data centre's own ultimate load, which is stated openly and unchanged. Where the forecast is withheld, no one outside the process can test how much headroom remains, or how quickly a build obligation turned into a switching instruction.
Chapter 6§
First reading — What changes -- and what Countability watches
Historical evidence at the first-reading register and assessment cutoff. The register moves quietly: two applications at one station went from live to withdrawn between vintages, both still flagged committed against the issuer's own stated rule, and no public document says why. A public web archive of the issuer's own feed is what makes the change visible at all -- and two statistical tables publish one series twice. The watch points, and the capture cadence that makes them checkable, are named here.
| Period | Value | Role | Assurance | Basis |
|---|---|---|---|---|
| Register list vintage 2026-07-10 — the withdrawn Honda Alliston connection application (CAA 2024-802), applicant of record Hydro One Networks Inc. | 431.0 MW | institutional estimate | — | The register row's own fields, quoted exactly: Applicant 'HYDRO ONE NETWORKS INC.'; Name 'Honda Alliston ‐ E8V E9V 230kV Connection'; Size '431 MW'; SiaStatus… |
| Table 25-10-0015-01, Ontario monthly generation — published reference months at the 2026-08-03 response | 221.0 reference months | institutional estimate | — | Count of vectorDataPoint entries in the archived Web Data Service response for vector v44174769 (2008-01 through 2026-05). |
| Table 25-10-0016-01, Ontario monthly generation — published reference months at the 2026-08-03 response | 221.0 reference months | institutional estimate | — | Count of vectorDataPoint entries in the archived Web Data Service response for vector v44159114 (2008-01 through 2026-05). |
| Register vintage of 2026-06-01 (web archive) — the Honda Alliston application, then recorded Active | 431.0 MW | institutional estimate | — | The same application, one vintage earlier: CAA 2024-802, applicant of record Hydro One Networks Inc., Size '431 MW', SiaStatus 'Active', Committed 'Yes',… |
| Register vintage of 2026-06-01 (web archive) — a second Alliston application, then recorded Complete | 24.0 MW | institutional estimate | — | CAA 2025-839, 'Alliston TS T2 - Load Increase', applicant of record Hydro One Networks Inc., Size '24 MW', SiaStatus 'Complete', Committed 'Yes', proposed in… |
| Register vintage of 2026-07-10 — the second Alliston application, now recorded Withdrawn, its assessment still posted | 24.0 MW | institutional estimate | — | CAA 2025-839 in the current vintage: SiaStatus 'Withdrawn', Committed still 'Yes', Size '24 MW'. Its posted assessment report remains linked on the withdrawn… |
| Comparison | Movement | Convention |
|---|---|---|
| Tables 25-10-0015-01 and 25-10-0016-01 — the two published monthly Ontario generation series, all shared reference months | +0.0 reference months | Pairwise equality across every shared reference month of the two archived responses: 221 of 221 months identical, zero differing values (re-derived by the Brief's test from the archived bytes). The two tables publish… |
| Two Alliston connection applications, one vintage apart: Active and Complete, then both Withdrawn | not comparable — Both sides state the same quantity. What changed is the application's recorded state, which is not a numeric difference; reporting a difference of zero would conceal the only thing that moved. | The same register, two vintages. In the web archive's capture of 2026-06-01 the 431 MW Honda Alliston application (CAA 2024-802) is recorded Active and the separate 24 MW Alliston TS application (CAA 2025-839) is… |
How much new electricity demand is formally waiting to connect to Canadian grids -- and how much of the projected data-centre and industrial load will actually materialize?
What is missing: No public, machine-readable, openly licensed national series exists for connection-queue or requested-load demand -- the megawatts of proposed data-centre and industrial projects that have formally asked to connect. Provincial system operators publish connection-process material at varying grain, but applicant-level queue detail is confidential under the operators' own processes, published site content does not carry terms extending to third-party analytical reuse, and no federal or Statistics Canada series aggregates requested connection capacity at any grain.
Consequence: The Electricity Delivery Brief reads the supply side of the official projections: the pace at which generation and capacity must grow under each scenario, and the pace the measured record shows. The demand side of the same story -- whether the data-centre and industrial load growth the scenarios' own definitions bracket is actually arriving in connection requests -- cannot be tracked from any public national series. The Brief therefore restates what the scenarios assume about demand and measures delivered supply; it does not and cannot publish an independent measure of queued demand.
Directly observed
Estimated, projected, or otherwise not yet an audited outcome
- August 14, 2026 list vintage — records
- August 14, 2026 list vintage — population
- Whole-register July 10 to August 14 change — withdrawals
- Whole-register July 10 to August 14 change — completions
- Whole-register July 10 to August 14 change — reversals
- Final connection assessment of 2023-07-10 — the assessed station maximum for the Windsor battery-plant station (CAA 2022-726)
- Final connection assessment of 2025-09-19 — the assessed station maximum load for Centennial TS (CAA 2023-766)
- Final connection assessment of 2023-04-21 — Algoma Steel EAF Stage 1 (CAA 2021-694/695)
- Final connection assessment of 2024-06-12 — Algoma Steel EAF Stage 2B (CAA 2023-768)
- Final connection assessment of 2025-06-12 — Algoma Steel EAF Stage 3, the facility's full assessed level (CAA 2024-787)
- Final connection assessment of 2024-10-16 — the Toronto data centre's ultimate load (CAA 2024-795)
- Final connection assessment of 2021-06-10 — the existing Dofasco station's assessed one-time increase (CAA 2021-693)
- Register list vintage 2026-07-10 — every record in the feed
- Register list vintage 2026-07-10 — load-class applications with a stated Size of at least 75 MW
- Register list vintage 2026-07-10 — population members whose assessment status reads Complete
- Register list vintage 2026-07-10 — population members whose assessment status reads Active
- Register list vintage 2026-07-10 — population members whose assessment status reads On-Hold
- Register list vintage 2026-07-10 — population members whose assessment status reads Withdrawn
- Register list vintage 2026-07-10 — population members whose proposed in-service field already reads In-Service
- Register list vintage 2026-07-10 — load-class records excluded from the population because their Size is stated only in megavolt-amperes (at or above 75 MVA)
- Register list vintage 2026-07-10 — distinct Applicant field spellings across the full register
- Register list vintage 2026-07-10 — groups of applicant spellings that collapse together under a stated normalization
- Register list vintage 2026-07-10 — the Centennial TS register row's stated Size (CAA 2023-766)
- Register list vintage 2026-07-10 — the Dofasco decarbonization application's stated Size (CAA 2021-712), On-Hold, no posted assessment
- Register list vintage 2026-07-10 — population members carrying at least one posted assessment-report link
- Register list vintage 2026-07-10 — population members carrying no posted assessment report
- Register list vintage 2026-07-10 — the largest Active application (CAA 2025-833), no posted assessment
- Register list vintage 2026-07-10 — the second-largest Active application (CAA 2025-848), no posted assessment
- Register list vintage 2026-07-10 — the third-largest Active application (CAA 2025-863), no posted assessment
- Register list vintage 2026-07-10 — the fourth-largest Active application (CAA 2024-810), no posted assessment
- Final connection assessment of 2019-09-12 — the stated load-security criterion for the Leamington-area circuit pair (CAA 2018-633)
- Final connection assessment of 2019-09-12 — load along the corridor interruptible by configuration at the 2019 vintage (CAA 2018-633)
- Addendum of 2020-11-17 — the restated interruptible-load aggregate at the 2020 vintage (CAA 2018-633 Addendum 1)
- Final connection assessment of 2024-06-12 — the regional interface transfer limit stated in the Stage 2B assessment
- Central-West Bulk Plan of 2024-04-18 — firm load in the London area, as the issuer states it
- Central-West Bulk Plan of 2024-04-18 — potential load beyond the firm load, as the issuer states it
- Central-West Bulk Plan of 2024-04-18 — the issuer's own stated total of firm plus potential load ('900 MW in total')
- 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
- 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
- Final addendum of 2025-06-30 — the three-station total the applicant was required to stay below (CAA 2024-795)
- Final Addendum 2 of 2026-02-04 — the same three-station total, now a real-time switching threshold (CAA 2024-795)
- Final Addendum 2 of 2026-02-04 — the data centre's own ultimate load, restated unchanged (CAA 2024-795)
- One circuit pair, two assessment vintages: the 2019 interruptible-load finding against the 2020 restatement
- Register list vintage 2026-07-10 — the withdrawn Honda Alliston connection application (CAA 2024-802), applicant of record Hydro One Networks Inc.
- Table 25-10-0015-01, Ontario monthly generation — published reference months at the 2026-08-03 response
- Table 25-10-0016-01, Ontario monthly generation — published reference months at the 2026-08-03 response
- Register vintage of 2026-06-01 (web archive) — the Honda Alliston application, then recorded Active
- Register vintage of 2026-06-01 (web archive) — a second Alliston application, then recorded Complete
- Register vintage of 2026-07-10 — the second Alliston application, now recorded Withdrawn, its assessment still posted
- Tables 25-10-0015-01 and 25-10-0016-01 — the two published monthly Ontario generation series, all shared reference months
Unresolved
- One project, two issuer surfaces: the Centennial TS register row against its own final connection assessment
- One three-station limit, two assessment vintages: a build obligation replaced by a switching instruction
- No located public document states any plant's own operating demand. Ontario's connection record states what a station is assessed to supply -- 150 MW at the Windsor battery-plant station, 331.2 MW at the new St. Thomas station -- and no located document states that a plant is its station's only load, or what share of the station's assessed maximum the plant itself uses. The one public document that does state a St. Thomas plant utility quantity is the city's wastewater master plan, and that figure is the municipal planner's own assumption, not the company's statement.
- No located Ontario document publishes a per-user split of a shared station capacity. The clearest instance is on the record: Hydro One's Northwest Ontario Needs Assessment states Port Arthur TS #1's capacity (59 MW after refurbishment) and names the two parties it supplies -- Hydro One Distribution and Synergy North -- but its forecast table carries a single combined row, and neither party's share is published anywhere located.
- Of the 67 large load applications in the register's population at the 2026-07-10 vintage, 47 carry no posted assessment report -- including all four active applications above 400 MW (707, 695, 550, and 453 MW as the register states them). Posting is a strong tendency, not a rule: some on-hold and withdrawn applications do carry posted reports, so no status explains the boundary. The issuer states unposted final reports are obtainable by email, by application ID.
- No public document states how much electricity Ring of Fire mining development would draw. A transmission line toward the area is now a designated provincial priority: on 2026-01-28 Hydro One announced that Ontario had designated it to build the Greenstone Transmission Line, a single-circuit 230 kV line from the existing East-West Tie near Nipigon Bay, through Longlac Transformer Station, to a new switching station at or near Aroland First Nation, expected in service in 2032 — in the announcement the province's energy minister described it as 'delivering the energy backbone and infrastructure to unlock the Ring of Fire's vast mineral potential'. That announcement states no megawatt figure for any Ring of Fire load, and neither does the transmitter's own current regional planning cycle: the Northwest Region Needs Assessment of 2025-09-03 and the Scoping Assessment of September 2025 do not name the Ring of Fire at all, while describing the region's demands — 'such as mining operation, data centers, forestry companies and large industrial manufacturers' — as 'distinctive, urgent and ever evolving'.
- The load forecast that drives a published shared-capacity requirement is not published. In the connection assessment for a Cambridge-area data centre, the system operator states that the applicant's updated forecast for three named stations is projected to exceed a stated 400 MW during the study period, and imposes a real-time switching requirement on that basis — while placing the forecast itself in a confidential appendix ("Table 1 of Appendix A (Confidential) shows the updated load forecast"). The assessments behind the finding are in a second confidential appendix. The threshold and the remedy are public; the quantity that crosses the threshold, and the year it crosses, are not.
- Two Alliston connection applications, one vintage apart: Active and Complete, then both Withdrawn
- No public, machine-readable, openly licensed national series exists for connection-queue or requested-load demand -- the megawatts of proposed data-centre and industrial projects that have formally asked to connect. Provincial system operators publish connection-process material at varying grain, but applicant-level queue detail is confidential under the operators' own processes, published site content does not carry terms extending to third-party analytical reuse, and no federal or Statistics Canada series aggregates requested connection capacity at any grain.
Key evidence
| Issuer | Publication | Published | Vintage | Source |
|---|---|---|---|---|
| Independent Electricity System Operator | System Impact Assessment, CAA ID 2022-726 (Windsor Stellantis TS — new DESN station; applicant of record Hydro One Netwo | 2023-07-10 | Final Report of 2023-07-10, captured 2026-08-03 | Source → |
| Independent Electricity System Operator | System Impact Assessment, CAA IDs 2021-694 and 2021-695 (Algoma Steel new load facility and generation reconnection — on | 2023-04-21 | Final Report of 2023-04-21, captured 2026-08-03 | Source → |
| Independent Electricity System Operator | System Impact Assessment, CAA ID 2023-768 (Algoma Steel EAF project, Stage 2B) — Final Report, Public | 2024-06-12 | Final Report of 2024-06-12, captured 2026-08-03 | Source → |
| Independent Electricity System Operator | System Impact Assessment, CAA ID 2024-787 (Algoma Steel EAF project, Stage 3) — Final Report, Public | 2025-06-12 | Final Report of 2025-06-12, captured 2026-08-03 | Source → |
| Independent Electricity System Operator | System Impact Assessment, CAA ID 2024-795 (GrandBridge Energy TOR1 data centre) — Final Report, Public | 2024-10-16 | Final Report of 2024-10-16, captured 2026-08-03 | Source → |
| Independent Electricity System Operator | System Impact Assessment, CAA ID 2021-693 (ArcelorMittal Dofasco Bayfront customer station — load increase) — Final Repo | 2021-06-10 | Final Report of 2021-06-10, captured 2026-08-03 | Source → |
| Independent Electricity System Operator | System Impact Assessment, CAA ID 2018-633 (Leamington TS DESN #2; applicant of record Hydro One Networks Inc.) — Final R | 2019-09-12 | Final Report of 2019-09-12, captured 2026-08-03 — superseded | Source → |
| Independent Electricity System Operator | System Impact Assessment, CAA ID 2018-633 — Addendum 1 (2020) | 2020-11-17 | Addendum of 2020-11-17, captured 2026-08-03 — the governing | Source → |
| Independent Electricity System Operator | Central-West Bulk Plan (2024-04-18) | 2024-04-18 | Report of 2024-04-18, captured 2026-08-03 | Source → |
| Hydro One Networks Inc. | Needs Assessment Report — Northwest Ontario (2020-07-17) | 2020-07-17 | Report of 2020-07-17, captured 2026-08-03 | Source → |
| Independent Electricity System Operator | Burlington to Nanticoke Integrated Regional Resource Plan (2024-12-18) | 2024-12-18 | Report of 2024-12-18, captured 2026-08-03 | Source → |
| Independent Electricity System Operator | System Impact Assessment, CAA ID 2024-795 — Final Addendum Report (No. 1, Public); GBE TOR1 Data Center, applicant Grand | 2025-06-30 | Final Addendum Report of 2025-06-30, captured 2026-08-04 | Source → |
| Independent Electricity System Operator | System Impact Assessment, CAA ID 2024-795 — Final Addendum 2 Report (Public); GBE TOR1 Data Center, applicant GrandBridg | 2026-02-04 | Final Addendum 2 Report of 2026-02-04, captured 2026-08-04 — | Source → |
| Independent Electricity System Operator | IESO Connection Assessment & Approval — Application Status list (the page's own backing feed, applicationstatus | 2026-07-10 | register list vintage 2026-07-10, captured 2026-08-03 | Source → |
| Independent Electricity System Operator | IESO Connection Assessment & Approval — Application Status page (the register's public face; the citation witne | 2026-07-10 | page statement 'Last Updated: July 10, 2026', capt | Source → |
| Statistics Canada | Electric power generation, monthly — table 25-10-0015-01, Ontario / total all classes of electricity producer / total al | 2026-08-03 | WDS response of 2026-08-03; latest reference month 2026-05 | Source → |
| Statistics Canada | Electric power generation, monthly, by producer and generation type — table 25-10-0016-01, Ontario totals (vector v44159 | 2026-08-03 | WDS response of 2026-08-03; latest reference month 2026-05 | Source → |
| Independent Electricity System Operator | System Impact Assessment, CAA ID 2023-766 (Centennial TS: New Station; applicant of record Hydro One Networks Inc.) — Fi | 2025-09-19 | Final Report of 2025-09-19, captured 2026-08-03 | Source → |
| Independent Electricity System Operator (register); Internet Archive (capture) | IESO Connection Assessment & Approval — Application Status backing feed, prior vintage recovered from the Internet A | 2026-06-01 | Internet Archive capture of the issuer's feed, timestam | Source → |
| Independent Electricity System Operator | IESO Connection Process — Frequently Asked Questions | 2026-08-04 | captured 2026-08-04 | Source → |
| Independent Electricity System Operator | IESO Application Status backing feed, list vintage 2026-08-14 | 2026-08-14 | register list vintage 2026-08-14, captured 2026-09-02 | Source → |
| Independent Electricity System Operator | IESO Connection Assessment & Approval — Application Status page (the register's public face; the citation witne | 2026-08-14 | page statement Last Updated August 14, 2026, captured Septem | Source → |
Method and limitations
- Every figure on this Brief resolves to a pinned value inside its two member Resolutions, each re-derivable from archived source bytes: register counts are re-derived by a committed census script from the archived feed -- the counting rule (load-class application types, size stated in megawatts, at or above the issuer's own large-load threshold) is published with the counts, and records the rule excludes are counted and named, never silently dropped -- and every assessed quantity is the issuer's own stated figure, quoted from the archived assessment. Nothing here sums, allocates, or nets any capacity quantity: the only sums on the page are the issuer's own, quoted with attribution. Station quantities are never restated as plant demand. Where this Brief cites Ontario monthly generation context, it treats Statistics Canada's two monthly generation tables as one measurement, not two: the archived responses show they publish identical Ontario series at every shared reference month. This is a first reading from a single register vintage; what it cannot yet show is stated in the open rather than modelled.
- 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.
- The register's Size field has no issuer-stated definition; it records an application's own stated quantity, which is sometimes an increment and sometimes not. No sum of Size values is meaningful, and none is published here.
- The population rule (load-class, megawatt-stated, at least 75 MW) is Countability's stated counting rule over the issuer's own fields — the issuer publishes no such population. Changing the rule would change the counts; the rule is therefore stated with the counts, here and on the Brief, and the archived register makes every count checkable.
- One register vintage shows states, not transitions. What entered, left, or changed status becomes observable only when a later vintage is captured; the issuer overwrites the register in place and publishes no history.
- Applicants of record are frequently transmitters or distributors, not the businesses whose projects the register rows name. Nothing here attributes an application's quantity, or its withdrawal, to the named project's proponent.
- The 431 MW Honda Alliston row is reported exactly as the register states it, including the issuer's own unreconciled Withdrawn/Committed contradiction. Why it was withdrawn, and what it implies for the project, is not in the public record.
- A prior register vintage used here comes from the Internet Archive's capture of the issuer's own feed, not from a Countability capture. It is cited as what the issuer served on that date, with the archive named as the source of the copy.
- Both withdrawn Alliston rows still read Committed 'Yes'. The issuer's own Connection Process FAQ states the 'Yes' is removed when a project is placed in service, and that the 'same will be done for projects that have been “withdrawn” by their connection applicants'. Four of the register's 2,044 rows carry Withdrawn together with Committed 'Yes'; two of those four are these Alliston applications.
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