ComEd Capacity Charges
ComEd offers an hourly electricity pricing option known as Residential Real-Time Pricing ("RRTP"). With this pricing program there are separate charges for Capacity and Energy.
Capacity charges represent the amount of power generation capacity that is needed during peak demand times, which typically occur in the afternoon on hot summer days.
Energy charges vary hourly and represent the incremental cost of producing additional electricity and varies up and down based on supply and demand. For more information about the Energy charges see http://www.frugalnerd.com/blog/2010/02/comed-rrtp-intro/
How is the monthly Capacity Charge calculated?
The Capacity Charge has two components:
1. A "Capacity Obligation" that is based on your actual usage during the five system-wide peak load hours during the previous June through September. The Capacity Obligation is effective with the next June billing period.
To find the kWh usage information needed to calculate your Capacity Obligation: Log into www.thewattspot.com, click COMPARE BILLS tab, then click COMPARE button, then Download Data, then Download User-Selected Hourly Data, then start = 8/10/2009, end = 8/20/2009, then use the downloaded data to fill in the kWh for the dates/times shown.
2. A "Capacity Charge Rate" that is established based primarily on an auction in the electricity market in which ComEd is a member.
Following is a spreadsheet that you can use to calculate your monthly Capacity Charge, which is shown on line 13. Press the "Click to Edit" button to fill in your information.
