When the IESO flipped the switch on its Market Renewal Program (MRP) at 00:00 EST on 1 May 2025, Ontario moved from a single system price to nodal Locational Marginal Pricing (LMP) and added a Day-Ahead Market (DAM). One week in, four lessons stand out.
Extremes arrived straight out of the gate
- Zero-dollar nights. Over-procurement pushed most overnight intervals to $0/MWh on day 1 while IESO was still in a conservative operating state.
- Five-minute whiplash. On 3 May the Ontario Zonal Price (OZP) ran from $14 to $199/MWh inside a single hour—proof that real-time price signals now move as fast as any in North America.
- Congestion blows the lid off. Four intervals on 5 May saw the West zone slam into the $2 000/MWh price cap while most other zones sat below $14; the congestion component alone exceeded $1 900/MWh.
- Cut-over stayed on the rails. By 4 May the IESO posted “Renewed Market Cycle Complete” after the first full DAM-to-real-time run.
Day-Ahead and Real-Time parted ways
The first complete cycle (trade-day 4 May) closed with an average DAM price of $2/MWh against a real-time average of $13/MWh; a single-hour spread topped $100/MWh. Ignoring intra-day re-offers now comes at a cost.
Operating Reserve quietly stole the show
Across the week, Operating Reserve (OR) premiums out-earned energy. DAM OR cleared as high as $600/MW, and real-time OR peaked at $526/MW. For many gas turbines, hydro units and batteries, reserve revenue now eclipses energy margins.
The next catalyst: virtual trading opens 8 May
With prudential systems now online, the IESO begins authorizing virtual traders today. We expect fresh liquidity, wider DAM-RT spreads and more price discovery in zones that were quiet during Week 1.
Practical Guidance
For generators
- Re-price offer curves daily; yesterday’s bids won’t capture today’s congestion.
- Compare OR vs. energy every morning—the payoff changed on 1 May.
- Check PPA language on negative prices and revenue floors; the risk is now real.
For large C&I consumers
- Deploy minute-level price alerts; a $150/MWh spike can land inside one production run.
- Re-evaluate load-shifting economics: overnight zeros and afternoon $150+ prints appeared in the same 24 hours.
- Explore OR participation—compressors, chillers and battery-backed sites already qualify.
Turning signals into strategy
Raw data are plentiful; actionable insight is scarce. Rodan’s MarketIQ™ streams every DAM and real-time LMP, congestion component and OR price in near-real-time, layered on two decades of history, so trading strategies keep pace with a market that now settles every five minutes.
The key takeaway
Week 1 proved MRP is not “HOEP with a map.” It is a nodal, volatility-rich environment where $0 nights, four-figure congestion and triple-digit DAM-RT spreads can all happen before breakfast. With virtual trading now live, the learning curve only gets steeper—and the opportunity set larger—for those ready to act.
