Ontario
IESO (Independent Electricity System Operator); Ontario Energy Board regulates rates
Open door dressed in new gatekeeping: government now picks winners before IESO's technical process even starts.
24MW
energized in Ontario
3 with published capacity
Publishes a project-level list. Yes, Ontario publishes a project-level list, and it is better than most people assume, but it is Not a queue. The artifact is the IESO 'Application Status' page under Connecting to Ontario's Power System. Its own description: 'This list provides the status of all connection proposals (transmission, load, generation and ancillary services) that have submitted a connection application package and executed the required…
The record
- Operator detail
- Split, and the common "IESO or Hydro One" framing is only half right, it is both, sequentially, plus a third layer that is legally live but not yet operative. 1. IESO, reliability approver. Runs the Connection Assessment and Approval (CAA) process under Market Manual 1.4 and issues the System Impact Assessment (SIA) ending in a "Notification of Conditional Approval" or "Notification of Disapproval with Reasons".
- Route to power
- For a 100+ MW facility this is a transmission connection. There is no queue to join and no allocation to win, you run two studies in parallel with two counterparties and pay for whatever reinforcement you trigger. Step 0, Siting and pre-consultation. IESO "strongly recommends" a pre-application face-to-face with your consultants, the IESO and the transmitter before filing. Optional Technical Feasibility Study (IESO, cost-recovery, report is confidential and never published) and/or Hydro One Phase 0 Feasibility Study. For distribution-level screening, the OEB's Centralized Capacity Information Map shows LDC headroom. Step 1, Open with Hydro One.
- Typical timeline
- Two to five years, on the transmitter's own published number, and realistically longer for a greenfield 100+ MW load in a constrained zone. Hydro One, Transmission connection process page: "An average connection can take two to five years to complete.
- Binding constraint
- There is no Alberta-style cap and no Quebec-style block allocation. Ontario has never set an MW ceiling for data centres, never run an allocation call, and never declared a provincial moratorium. If you are looking for a single number, there isn't one. What binds is five separate things, and right now the sharpest two are legal limbo and municipal land use, not grid capacity per se. 1. Regulatory limbo, the top constraint as of 2026-08-01. Electricity Act s.28.1 has been in force since December 11, 2025 and prohibits connecting a "specified load facility" unless regulatory requirements are met.
- Behind the fence
- Yes, self-supply is legal and is being actively considered by hyperscalers in Ontario as a way around transmission timelines, but it is a lightly-mapped path, and nothing in 2025-26 was changed specifically to open it. The licensing test. OEB Act s.57(c): no person may generate electricity or provide ancillary services "for sale through the IESO-administered markets or directly to another person" without a generation licence. The trigger is sale, not generation.
- Interconnection
- IESO does not run a US-style sequential interconnection queue; it uses a 'committed projects' connection assessment and approval process (Market Manual 1.4). Bill 40 (in force 2025-12-11) added section 28.1 to the Electricity Act letting the government designate 'specified load facilities' (data centres meeting prescribed criteria) for prioritized, non-standard connection treatment. IESO is separately layering in new large-computational-load reliability standards through connection assessments in 2026, ahead of formal market rule changes.
- Tariff
- No dedicated data centre retail tariff exists yet; cost exposure comes through Locational Marginal Pricing (since 2025-05-01), connection asset payments, expansion deposits, and mandatory impact-assessment costs for facilities over 10 MW. The 'specified load facility' approval regime under Bill 40 is still being defined by regulation as of mid-2026.
- Years to grid power
- 3-5
- Years behind the fence
- n/a, no Ontario party publishes a behind-the-fence timeline for large load
- Basis for those years
- Grid figure: IESO states the connection process "can take anywhere from a few months for small modifications to existing facilities, to more than three years for major modifications or to connect new facilities", with Stage 2 approval alone typically one year and Stage 3 design and build 18 to 36 months. Hydro One puts an average transmission connection at two to five years. Three to five is the overlap of the operator floor and the transmitter range, both re-read 2026-08-02. Large computational loads sit above this: IESO's technical requirements for them were still in draft at the 2026-07-23 stakeholder webinar, so no timeline for that class is established. BTF figure: not published by any Ontario party.
Dated events
- Ontario announces its Data Centre Playbook and opens a 30-day public comment period, through the Environmental Registry of Ontario and the Ontario Regulatory Registry, on how large-scale data facilities connect to the grid. The government's own framework document is a draft: it calls itself the “Draft Data Centre Playbook”, says it is “under development”, and applies to data centres “that meet thresholds to be set out in a future regulation under the Electricity Act”. It is a framework and a consultation, not a filed regulation. The Playbook is anchored in three core principles for approving data centre connections to the grid, verbatim: (1) “Data centres must invest substantially, both financial and non-financial, in Ontario and local communities”; (2) “Data centres pay the full cost of electricity costs”; (3) “Ontario will only offer non-financial support to attract data centre investments”. Separately, and not to be confused with those principles, the document sets out three Strategic Priority Assessment pillars: Advance Economic Development; Protect Data Security and Digital Sovereignty; Invest in Communities and Earn Public Confidence.
- Oakville Council passes an Interim Control By-law at a special council meeting, restricting new data centres, enterprise computing facilities and similar high-intensity digital processing facilities for one year, extendable to two, under Section 38 of the Planning Act. Reported alongside it: a similar bylaw failed in Hamilton and a final vote is pending in Mississauga. Municipal land use remains a live constraint on Ontario siting independent of provincial connection policy.
- Mississauga council votes unanimously for an Interim Control By-Law pausing approvals of new AI data centre developments city-wide for up to one year, extendable a further year, the first such municipal pause in Ontario.
- Minister of Energy and Mines Stephen Lecce states that data centres seeking grid access must demonstrate community benefits, pay the full cost of the electricity they consume, and meet provincial priorities: 'It is not your right'; 'if a data centre wants to e…
- Reported that the IESO is applying its new large computational load reliability standards, including the revised voltage ride-through standard governing when a large computational load must stay connected during a voltage disturbance and when uninterruptible-power-supply-supported demand may partially or fully transfer from the grid.
- IESO holds its public engagement webinar on the large computational load technical requirements, presenting stakeholder feedback and revised requirements posted July 15. Final feedback deadline July 31, 2026.
- IESO launches the Major Projects Identification Committees (MPIC) process, a voluntary early-identification intake for large projects (reported threshold 10 MW and above) to improve demand forecasting and assess readiness for connection.
- IESO posts draft Technical Requirements for Large Computational Loads Connecting to the Ontario Power System, adding performance requirements the Market Rules did not previously carry for AI and cryptocurrency facilities.
- IESO publishes the 2026 Annual Planning Outlook (Ontario's electricity system needs 2027-2050). Reference demand growth 65% to 2050 (high case 92%, low 38%); 8 TWh energy need emerging in 2032; no significant incremental capacity needs until the mid-2030s; ove…
- Bill 40 receives royal assent as S.O. 2025 c.22 (first reading June 3, second November 17, third December 8, 2025). Schedule 1 comes into force on royal assent, so Electricity Act s.28.1 is law from this date.
Tracked projects
Announced capacity is what the proponent has stated. Energized capacity is what is drawing. They are different figures and are never summed. How the figures reconcile.
Sources
- IESO — Application Status (project-level connection assessment list)
- IESO — applicationstatusdata.json (raw data behind the Application Status grid, 2,044 records)
- IESO — Overview of the Connection Process (six stages, durations)
- IESO — Stage 2: Obtain conditional approval to connect (SIA/ESIA, CIA, deposits)
- IESO — Connection Process Frequently Asked Questions (monthly update cadence, deposit amounts, Committed column)
- IESO Market Manual 1, Part 1.4: Connection Assessment and Approval, Issue 24.0 (s.5.5 deposits, s.5.8 timelines/assessment ordering, s.5.9 reports)
- IESO — Technical Requirements for Large Computational Loads Connecting to the Ontario Power System (engagement)
- IESO — Major Projects Identification Committees (MPIC) Process
- IESO Demand & Conservation Planning Technical Paper: Large Step Loads — Spotlight on data centres and electric vehicle supply chain
- IESO — 2026 Annual Planning Outlook: Ontario's electricity system needs 2027–2050
- Government of Ontario — Data Centre Playbook, media backgrounder (August 13 2026; read in full: three core principles, Strategic Priority Assessment pillars, 30-day comment period through the ERO and ORR)
- Town of Oakville — Council approves Interim Control By-law related to data centres (special council meeting, August 11 2026)
- Canada's National Observer — Ford to municipalities opposing data centres (announcement event, Guelph; municipal context; Bill 40, the Protect Ontario by Securing Affordable Energy for Generations Act)
Known gaps. Things Could not establish from public sources I actually fetched. These are real holes, not hedging. 1. No confirmation the s.28.1 regulation has been made. Verified ERO 025-1001 still shows proposal status with no decision section, and July 2026 legal commentary and July 28, 2026 news reporting both say the criteria are unpublished. But I did not read the Ontario Regulations index or the e-Laws source-law table directly, e-Laws requires JavaScript and returned no text to my fetches, and CanLII returned 403. Section 28.1 regulation, checked 2026-08-16. No regulation defining the requirements for a “specified load facility” has been located as filed, on e-Laws or the Environmental Registry. The September 2025 ERO notice, comments closed 2025-11-04, proposed ministerial approval before connection and defined a specified load facility as data centres and other prescribed entities. The government's own Data Centre Playbook document of 2026-08-13 settles the question from the primary side: it applies to data centres “that meet thresholds to be set out in a future regulation under the Electricity Act”, which is the province saying in its own words that the regulation is still to come. The Playbook is therefore not the s.28.1 regulation and must not be described as one. Playbook elements held back, checked against the primary document 2026-08-16. Three items widely reported after the announcement are not recorded on this card because they are not in the government's document. (a) A higher electricity rate for data centres over 1 MW than other industrial users: no 1 MW threshold appears anywhere in the document; it lists a “Separate Electricity Rate Class for Data Centres” as a consultation posting component and describes restricting Industrial Conservation Initiative eligibility and/or a specific data centre rate as an initiative “Under Consideration, Outside of the Playbook”. (b) Closed-loop cooling as an approval condition: closed-loop cooling appears only as an example of minimising environmental impact under Pillar 3, and again in an appendix describing technology. The stronger “prioritizing builds with closed-loop systems” formulation is the Premier's spoken remark at the press conference, not framework text. (c) An exact consultation close date: the document states a 30-day comment period beginning 2026-08-13 and gives no close date, so none is published here. The 2026-08-13 news release page at news.ontario.ca returned no body text to either fetcher on the run date, so the framework document is cited instead of the release. Reported IESO draft technical requirements for large computational loads, said to have been posted 2026-05-14, could not be located on ieso.ca and are not recorded. Independence. All Playbook coverage traces to the single 2026-08-13 announcement; the government's own documents are the confirmation and the outlets supply only the event date. Law-firm insights and their syndicated mirrors count as one source each.
Record updated 2026-08-16. Sources reviewed 2026-08-16. Corrections: sam@mccordinvestments.com