2009 State of the Market Report
Shadow Price ($/MWh)
Figure 71: Midwest ISO Market-to-Market Constraints Relief Requested and Shadow Prices, 2009
PJM Shadow Price MISO Shadow Price Relief Requested
Relief Requested (MW)
Intial Post 48% Crete-St. John
Dune Acres- Michigan City
Intial Post 53% Pana XFMR
Oak Grove- Galesburg
Share of Active Hours Coordinated
The three most common flowgates for market-to-market coordination are those that limit flows from west to east: (1) Crete-St. John, (2) Dune Acres–Michigan City, and (3) Oak Grove– Galesburg. PJM has made changes that have allowed it to provide substantially more relief than in prior years when the Midwest ISO activates a market-to-market constraint. PJM’s response to Midwest ISO constraints is now comparable the Midwest ISO’s response to PJM’s constraints.
The figure also shows the shadow prices tend to decrease and move toward convergence over the duration of the event. However, in comparing these results to those for the PJM constraints, we find the reductions in the Midwest ISO’s shadow prices have been much smaller, and the shadow prices do not converge as well after the coordination is initiated. This suggests that additional cost-effective relief may be available from PJM. The improvement to the relief software may improve these results, although we recommend that the RTOs work together to identify any other modeling parameters, provisions, or procedures that may be limiting PJM’s relief.