This chart shows a typical day of electricity demand in Ontario on July 5, 2010. It is provided by the IESO website at this link: http://www.ieso.ca/default.asp
Notice that lowest actual demand for the day was at 5:00 a.m./~14,000 megawatts and the project high will be at 5:00 p.m / ~23,800 megawatts. The difference between the projected high and the low is 9,800 megawatts.
Here’s a graph showing the weekly demand from Aug. 23 – Aug. 29. Notice the weekly low on Aug. 28/~12,000 megawatts and the weekly high on Aug. 29/~20,000 megawatts. The average available demand capacity is ~ 27,000 megawatts. The above graphs are typical of electricity demand throughout most parts of North America. The actual numbers will be different but the shapes of the graphs are consistent.
My residential electricity consumption – Sept. 17, 2009 to Sept. 17, 2010 / 8760 data points – (24 hours x 365 days)