2009 State of the Market Report
Figure 26: Real-Time Hub Prices and Load 2009: Off-Peak Hours
Cinergy Hub Minnesota Hub WUMS Area Michigan Hub
Apr-09 May-09 Jun-09 Jul-09 Aug-09 Sep-09 Oct-09 Nov-09 Dec-09
Energy prices were generally very low during off-peak hours. Higher levels of wind generation occurred in off-peak hours and a high percentage of off-peak hour prices were set by coal-fired resources. Off-peak prices were volatile in 2009. There was a consistent daily price spread of $6 and $8 per MWh between the western and eastern hubs. The persistent west-to-east congestion throughout the year resulted in 25 days with negative average off-peak prices at both the Minnesota Hub and WUMS. Congestion into eastern areas in early March was caused by several forced and planned generator outages, as well as substantial volumes of wheeled transactions from IESO to PJM.
Figure 27 and Figure 28 show average real-time prices by time of day in the winter and summer months of 2009, when loads are the highest. Volatility decreased significantly in 2009 under the ASM market because the real-time market now has the flexibility to jointly optimize the use of resources for energy and ancillary service needs. To examine the drivers of the price fluctuations, the figures show the effective “headroom” on the system. Headroom is the amount