Ontario caps an inverter plant at 75 MW on a 115 kV line in its next contract round - Belleville's list is 10 MW of solar and a 60 MW battery, and a local factory feeder is off the map
On 23 October 2026 the IESO posted preliminary connection guidance for the second window of its Long-Term 2 energy and capacity tenders. The document is dated 15 October 2026. An inverter-based plant is limited to 75 MW on a 115 kV circuit, 200 MW on a 230 kV circuit in northern Ontario, and 250 MW on a 230 kV circuit in the south. Belleville's listed target is at least 10 MW of solar and 60 MW of battery. Toronto is closed for this round on short-circuit grounds. A battery on a local distribution feeder is outside the map.
A workplace battery sits on the customer's side of the meter. The map the Ontario grid operator posted this week is for companies bidding to build power plants the province will contract. The two are different sockets.
On 23 October 2026 the Independent Electricity System Operator posted preliminary connection guidance for the second window of the Long-Term 2 tenders. One tender buys energy, LT2(e-2). The other buys capacity, LT2(c-2). The PDF is issue 1.0, dated 15 October 2026. The study cases include projects expected in service up to 2032, the year the guidance uses for these plants. An earlier October note on this desk, the regulation-service draft, is a different paper. That one is about a transmission battery selling balancing service. This one is about where a new plant can sit.
Size caps, for an inverter-based plant. The guidance calls these bright-line limits. On a 115 kilovolt circuit, north or south, the cap is 75 megawatts. On a 230 kilovolt circuit in northern Ontario, the cap is 200 megawatts. On a 230 kilovolt circuit in southern Ontario, the cap is 250 megawatts. Separate from those, any one proposal is limited to 250 megawatts on a single circuit, whatever the technology. Some circuits are tighter than the bright line. Some are marked not allowed, and a bid on those is treated as non-deliverable. A bid on a circuit the guidance flags as higher risk can still be filed. The deliverability test is where that risk shows up.
Belleville is the line that names solar and a battery together. The guidance, drawing on the Eastern Ontario bulk plan, says the local target is at least 10 megawatts of solar and 60 megawatts of battery storage. Hitting either target counts. Both is the preferred path where it can be done. Solar bids go into the energy tender. Storage bids go into the capacity tender. The plant connects on the distribution side at Belleville DESN, or with a dual transmission connection on circuits H23B and T25B. It also provides reactive power, up to 33% of its rated power, whenever it is not on outage. The page prints megawatts. It does not print how many hours the 60 megawatt battery holds.
Two other named spots, so the Belleville line is not read as the whole map. North of Sudbury, on the Kirkland Lake 115 kilovolt system, the guidance looks for solar or thermal generation on circuit K4, for voltage support, and it prints up to 50 megawatts of room on that circuit. A battery is not the resource named there. Around Sault Ste. Marie, the guidance looks for 95 megawatts of firm, dispatchable plant on named 115 kilovolt circuits (ALGOMA1, ALGOMA2, ALGOMA3, CLERGUE1, CLERGUE2 or LEIGHBY1), able to stay on through a single element outage. Those circuits are for the capacity tender. The guidance says connections there are not allowed under the energy tender.
Toronto is closed for this round. The guidance says area and inverter limits were not set for Toronto, because short-circuit limits block connections across the area for these tenders. Hydro One lists stations already tight on short circuit, including Cherrywood, Manby, Richview, Leaside and Hearn, and it points to a distance of about 50 kilometres, electrical, from stations with that limit. A short-circuit test still runs on every proposal, wherever it sits.
A small battery has a grounding line of its own. The guidance says a battery with a small footprint may not have a ground grid large enough to hold ground potential rise under 5 kilovolts, the level named from the Ontario Electrical Safety Code. Hydro One overhead shield wires, skywires, are not a substitute. A skywire can break in a fault and leave the battery's ground grid on its own. The guidance says the ground grid at the battery is designed to meet the 5 kilovolt line without those skywires. A battery near Hydro One transmission gear is also covered by Hydro One's battery fire standard. The guidance names that standard. It does not print a setback in metres.
Where a factory feeder sits. Energy-area limits in the guidance apply to plants with a capacity factor under 50%. Capacity factor is the energy a plant delivers over a year, divided by the energy it would deliver running at full power the whole time. Under 50% means less than half of that full-power year. The guidance says a higher capacity factor can mean less room, and it points those projects to a conversation with IESO staff. The document says it does not give guidance for feeders owned by other local distribution companies, beyond the capacity at distribution stations supplied from Hydro One. A battery on a factory feeder in a city served by a local utility is outside this map. The map also says the results of this round will make the same pages a poor guide for a later round.
Analogy: the PDF is a seating chart for plants that want a provincial contract out to 2032. 75 megawatts is the largest inverter guest on a 115 kilovolt line. Belleville has two place cards, 10 megawatts of solar and 60 megawatts of battery, and no hours on the battery card. The socket in a factory switch room is not a seat on that chart.
Good: A public posting date, a public document date, circuit caps in megawatts, and a Belleville line that separates solar from battery and names which tender each one enters.
Bad: No megawatt-hours on the 60 megawatt battery. No metre figure for the fire setback. No price, no contract term and no winning bid. The energy-area limits are for plants under a 50% capacity factor. Toronto is a block, not a list of spare megawatts.
Ugly: Reading 75 megawatts as the size of a workplace battery. Reading 10 and 60 as a project already bought. Putting a cabinet on a local factory feeder onto this transmission map. Using the 15 October regulation draft and this siting PDF as if they were one document.
Soft next step: set 75 MW, 10 MW and 60 MW next to the size on the quote. If the quote is a cabinet on a local factory feeder, this map does not price it.
Source: IESO news, 23 Oct 2026 - LT2 Window 2 preliminary connection guidance posted. Primary for the 23 October posting of the guidance for the LT2(e-2) energy tender and the LT2(c-2) capacity tender. IESO, Preliminary Connection Guidance for the Long-Term 2 Window 2 Requests for Proposals, issue 1.0, 15 Oct 2026. Primary for the 15 October issue date, study cases through an in-service year of 2032, the 250 MW per-proposal cap on a single circuit, inverter bright-line caps of 75 MW per 115 kV circuit in northern and southern Ontario, 200 MW per 230 kV circuit in the north and 250 MW per 230 kV circuit in the south, Belleville's target of at least 10 MW of solar and 60 MW of battery storage with either target acceptable and both preferred, solar into LT2(e-2) and storage into LT2(c-2), connection at Belleville DESN or a dual connection on H23B and T25B, reactive power up to 33% of rated power, up to 50 MW on circuit K4 north of Sudbury for solar or thermal voltage support, 95 MW of firm dispatchable resource on the named Sault Ste. Marie 115 kV circuits for the capacity tender with energy-tender connections there not allowed, Toronto left without area and inverter limits because short-circuit limits block the area, Hydro One's about-50 km electrical distance from short-circuit-limited stations including Cherrywood, Manby, Richview, Leaside and Hearn, ground potential rise under 5 kV for a small-footprint battery under the Ontario Electrical Safety Code, skywires excluded as a way to meet that line, the Hydro One battery fire standard with no metre setback printed, energy-area limits for capacity factors below 50%, and the statement that the document does not guide connections on distribution systems owned by other local distribution companies beyond Hydro One-supplied stations. The guidance does not print a battery duration, a contract price, or a workplace invoice. Not-allowed circuits are non-deliverable in the evaluation. This PDF is not the 15 October storage regulation design memo.