2009 State of the Market Report
VIII. External Transactions
As in prior years, the Midwest ISO continued to rely heavily on imports to serve its load and meet its operating reserve requirements. In this section, we evaluate the interchange between the Midwest ISO and adjacent areas. In particular, we summarize the quantities of external transactions and the efficiency of the transaction scheduling processes.
Import and Export Quantities
Figure 88 shows the daily average of hourly net imports scheduled in the day-ahead market. The Midwest ISO is on the whole a net importer of power in both peak and off-peak periods due to its reliance on large imports from the West and Manitoba. In 2009 there was no discernible seasonal pattern to net imports with high levels of imports throughout the year. Day-ahead imports averaged 3.4 GW in 2009 indicating substantial reliance upon net imports to satisfy the demands of the market. This average import level was a slight decrease from 3.6 GW in 2008.
Figure 88: Average Hourly Day-Ahead Imports All Hours, 2009
Net Imports (MW)
Net imports in the real-time market can vary substantially from the levels scheduled in the day- ahead market. Figure 89 shows the average hourly net imports scheduled in the real-time market