2009 State of the Market Report
Load and Resources
Mild summer and winter weather (except in January) also contributed to lower load in 2009. The figure shows that the total degree days decreased by almost 11 percent year-over-year. The largest monthly decline occurred in July when the coolest temperatures on record for much of the Midwest ISO footprint resulted in a 45 percent drop in total degree days. This decrease contributed to a 15 percent drop from the prior year in average load. Conversely, unusually cold January weather led to a relatively modest 1.7 percent load decline, the smallest monthly year- over-year load decrease in 2009.
While 2009 was a mild year in terms of heating and cooling requirements compared to 2007 and 2008, poor economic conditions were the primary driver of the reduction in demand. This is consistent with the fact that average load in 2009 was lower in every month compared to 2008, including months during which the HDD or CDDs were higher. The Chicago Purchasing Managers Index, a leading business barometer and a broad measure of regional economic activity, measured almost 8 percent lower in 2009 than in 2008.
The capacity in the figures below includes only capacity owned by entities that are participants in the Midwest ISO markets and excludes capacity owned by Midwest ISO reliability-only members (e.g. Manitoba Hydro, Western Area Power Administration). The Midwest ISO serves as the Reliability Coordinator for these entities, but reliability-only members do not submit bids or offers in the Midwest ISO wholesale markets. Including the resources of the reliability-only members, the total generating capacity for the Midwest ISO was nearly 160 GW in 2009. It had exceeded 170 GW by the end of 2008, but this amount declined when OPPD, NPPD, and Lincoln Electric System left the Midwest ISO for the Southwest Power Pool (“SPP”) in April 2009.
Generating resources in the Midwest ISO market footprint totaled nearly 137 GW by the end of 2009. Figure 9 shows the distribution of this capacity by coordination region.