Ontario’s IESO Awards 640 MW of Battery Storage
- Capacity & Wholesale Markets News Policy & Markets
Marin Holt
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- 7 minutes read
- Total capacity awarded: 640 MW
- Largest project: 300 MW Napanee Phase 2
- Contract term: 20-year capacity contracts
- Cost vs prior round: 36% below Expedited-LT1
- Commercial operation by: May 1, 2030
Ontario’s Independent Electricity System Operator (IESO) awarded 20-year contracts for 640 MW of new battery energy storage on June 17, 2026, the first capacity window of its Long-Term 2 (LT2) Request for Proposals. The three winning projects — all new-build systems carrying 50% Indigenous equity ownership — cleared at capacity costs 36% below the province’s Expedited-LT1 round and 16% below the earlier LT1 procurement, and are due to reach commercial operation by May 1, 2030.
The three projects
The largest award went to the Napanee Battery Energy Storage System Phase 2, a 300 MW facility in the Town of Greater Napanee developed with the Mississaugas of Scugog Island First Nation. The Eagle Lake Power Reserve, a 190 MW project near Oxdrift in the District of Kenora, partnered with the Eagle Lake First Nation. The Simcoe Battery Project, 150 MW in Norfolk County, is backed by Six Nations of the Grand River and the Mississaugas of the Credit First Nation. Each project holds a separate 20-year capacity contract with the system operator.
Critical Perspective
Ontario’s 640 MW battery storage award is a significant step in grid resilience, yet it fails to address the fundamental physics of inertia and grid stability that stationary energy devices must provide. The article notes a 36% reduction in cost from the previous round, but this overlooks the critical role of inertia, which batteries cannot fully replicate. According to Watt-Logic’s analysis, inertia provided by conventional generators is essential for maintaining grid stability, with each MW of generation offering approximately 0.5 MWh of spinning reserve. If the new battery storage lacks equivalent inertia, it risks destabilizing the grid during sudden load changes or system faults. The consequence of this oversight could be increased transmission congestion and higher maintenance costs as the grid struggles to manage these events without adequate inertia. The question remains: how will the 640 MW of batteries ensure stable operation when integrated with the existing fleet, particularly given that they only provide short-duration discharge, not the sustained support needed for grid stability?
Why It Matters
The award is a fresh price signal for anyone watching capacity markets. By procuring storage at rates well under its own prior rounds, the IESO showed that competitive solicitations keep pushing battery capacity prices down — a sharp contrast with US capacity auctions such as PJM’s, which cleared at their administrative cap for a second straight year. Grid planners also get a working template: half-Indigenous equity on every winning bid pairs reliability procurement with community ownership rather than running the two on separate tracks.
The LT2 RFP is part of Ontario’s plan to add roughly 1.6 GW of capacity as the province retires older resources and braces for electrification-driven demand growth. The June 17 awards are the first capacity window of that process, with further windows expected to follow.
What the awards do not settle is execution. All three projects must reach commercial operation by May 1, 2030, leaving roughly four years in which interconnection queues, transformer lead times and financing terms can still move delivered costs above the contracted prices. Batteries also swept the entire first LT2 capacity window, so Ontario’s near-term reliability addition now rests on a single technology class whose performance during extended winter peaks the province has yet to lean on at this scale.
Sources
- Energy-Storage.news — Ontario IESO procures 640MW energy storage in LT2 Request for Proposals
- RTO Insider — Battery Storage Sweeps Ontario’s 1st Long-Term 2 Capacity Window
- IESO / Government of Ontario — Ontario Secures Record-Low Electricity Capacity Costs
- Clean Energy Canada — The cost benefits of batteries for clean reliability
- Renewables Now — Ontario awards long-term contracts for 640 MW of battery storage
