¶ Ontario Market Renewal — Before vs After
Category: 📊 Reference
¶ Overview
The 2025 Market Renewal Program (MRP) redesigns Ontario’s wholesale electricity market to improve economic efficiency, transparency, and reliability.
Ontario’s original market design was implemented in 2002. Over time, several operational workarounds and settlement mechanisms were introduced to maintain system reliability.
The Market Renewal Program replaces many of these mechanisms with a modern market design that more closely aligns market outcomes with physical electricity system conditions.
¶ Market Design Comparison
| Feature | 2002 Market Design | Market Renewal Design |
|---|---|---|
| Energy Pricing | Single provincial price (HOEP) | Locational Marginal Pricing (LMP) |
| Market Scheduling | Primarily real-time market | Day-Ahead Market + Real-Time Market |
| Congestion Management | CMSC payments | Congestion reflected in LMP |
| Generator Commitment | Limited advance scheduling | Formal unit commitment process |
| Price Signals | Weak location signals | Strong locational price signals |
| Market Transparency | Limited congestion visibility | Transparent congestion pricing |
¶ 2002 Market Structure
In the 2002 Ontario electricity market:
This design means electricity prices are typically the same across the province, even when transmission constraints affect system operations.
As a result, additional settlement mechanisms are required to compensate market participants when dispatch instructions differ from market offers.
¶ Market Renewal Structure
Under the Market Renewal Program, the electricity market operates differently:
Electricity prices will vary by location depending on:
- transmission congestion
- line losses
- local supply and demand conditions
This structure reduces the need for additional settlement adjustments.
¶ Key Market Improvements
¶ Day-Ahead Market
The Day-Ahead Market allows electricity supply and demand to be scheduled one day before real-time operations.
Benefits include:
- improved price certainty
- better generation scheduling
- improved system planning
¶ Locational Marginal Pricing
Locational Marginal Pricing introduces electricity prices that vary by location.
Prices reflect three components:
- energy cost
- congestion cost
- transmission loss cost
This provides more accurate signals for where electricity should be produced or consumed.
¶ Reduced Reliance on Settlement Adjustments
Under the 2002 market design, reliability actions often require payments such as Congestion Management Settlement Credits (CMSC).
MRP reduces reliance on these payments by incorporating congestion and system constraints directly into electricity prices.
¶ Why Market Renewal Matters
Market renewal improves the alignment between market outcomes and physical electricity system operations.
Key benefits include:
- more efficient electricity dispatch
- improved investment signals for generation and storage
- better management of transmission congestion
- greater transparency in electricity pricing
These changes help ensure Ontario’s electricity market can adapt to evolving system needs.
¶ Example Scenario
Consider a situation where electricity demand is high in a particular region and a transmission line becomes congested.
¶ 2002 Market
- Electricity price remains uniform across Ontario.
- System operator must adjust generator output.
- Additional settlement payments may be required.
¶ Market Renewal
- Electricity prices increase in the constrained region.
- Local generators are economically dispatched.
- Congestion costs are reflected directly in market prices.
¶ Relationship to Other Topics
/glossary/mrp/glossary/lmp/glossary/cmsc/glossary/dam/basic/markets-operations/electricity-market-overview
Last Updated: YYYY-MM-DD