Independent Electricity System Operator (IESO)
The Independent Electricity System Operator is responsible for operating the electricity market and directing the operation of the bulk electrical system in Ontario.
IESO is considering a broader range of long-duration energy storage technologies in its upcoming long lead-time procurement (but will not include hydroelectric redevelopments, officials told stakeholders.
The reference scenario in IESO’s 2026 Annual Planning Outlook indicates net annual energy demand growth of 65% by 2050, from just over 150 TWh in recent years to 250 TWh.
IESO will implement new rules for breaking ties and reducing unfulfilled commitments in its capacity market ahead of its next auction Nov. 26-27.
After more than six months of operations under its Market Renewal Program, IESO is implementing “non-substantive” rule changes it says will improve clarity and alignment.
IESO will begin allowing corporate energy buyers to purchase power from off-site renewable generators next spring, giving loads another way to reduce their Global Adjustment charges.
IESO is considering ways to grow Ontario’s economy and secure its energy supply without relying on trade with its U.S. neighbors, just as President Donald Trump launched another salvo in his ongoing trade war on Canada.
IESO is seeking to reduce the risk of its procurement of long lead-time resources by reserving the right to reject proposals that are too expensive and cancel deals in the first few years.
IESO is asking generation owners what it will take to extend the lives of their units at the end of their current contracts as Ontario seeks ways to meet a projected 75% load increase by 2050.
IESO hopes to curtail 100 MW of commercial HVAC load next year under a new program targeted at resources available during system peaks, but not for the full six-month commitment of the capacity market.
Storage developers in Ontario are pushing back on IESO’s 100-MW/minute ramp limit for batteries, saying it will reduce their revenues.
Want more? Advanced Search










