The total electric power generation in the United States increased 1.7 percent compared to July 2010 the change in electric power generation does not necessarily coincide with the change in retail sales of electricity because utility billing cycles tend to lag electricity production in many areas. Over the same period, coal generation decreased 1.3 percent, while natural gas generation increased 2.2 percent. Petroleum liquids generation showed the largest percentage change, decreasing 46.3 percent due in part to the increased cost of petroleum liquids as a fuel used in electricity generation. Conventional hydroelectric generation increased 30.0 percent from the previous year, as riverflows in the Northwest showed signs of returning to normal following an abnormally long hydroelectric season.
Total coals stocks in the electric power sector decreased 11.0 percent from the previous month. Accordingly, the average number of days of burn for coal plants consuming bituminous or subbituminous coal as their primary fuel exhibited a similar decrease from the previous month.