2009 State of the Market Report
Load and Resources
Figure 10: Distribution of Generation Capacity by Region By Fuel Type, 2009
50,000 45,000 40,000 35,000 30,000 25,000 20,000 15,000 10,000
Other Oil Natural Gas Coal Water Wind Nuclear
The Midwest ISO continues to rely on coal-fired generating resources for the majority of its installed capacity (52 percent). Because coal units are generally baseloaded, they generate an even larger share (74 percent) of the total energy produced. The second largest fuel type is natural gas, which accounts for almost 28 percent of the generating resources in the Midwest ISO. These resources are more expensive than most of the other resources in the region and are therefore dispatched at a lower capacity factor, producing less than 18 percent of the energy in the region; although, they frequently set the price in peak hours. Nuclear units account for fewer than 8 percent of total capacity but produce 15 percent of the generation because they are among the lowest-cost resources and run at very high capacity factors. Continued growth in wind capacity (up 66 percent from 2008) has increased wind’s share of capacity and generation to 5.1 and 2.9 percent, respectively.
While the mix of generation is fairly homogeneous across the Midwest ISO footprint, certain regions have conditions that favor investment in particular generator types. The West region, for example, contains the vast majority of total wind generation (87 percent) due to the relatively attractive wind conditions in the area. Such concentrations can present operating and reliability challenges that are addressed later in the report.