Capacity factor
From Interwest Energy Alliance Wiki
The U.S. Energy Information defines "capacity factor" as the ratio of the electrical energy produced by a generating unit for the period of time considered to the electrical energy that could have been produced at continuous full power operation during the same period.
In its July 2007 "WindLetter," the American Wind Energy Association takes on the "myth that wind turbines operate only a small fraction of the time" in the following article:
Wind turbines at most sites generate power 50%-80% of the time. It’s true that the output amount of wind turbines is variable; however, here it’s important to note that no power plant generates at 100% “nameplate capacity” all of the time.
Nameplate capacity refers to the maximum generation potential of a power plant. A conventional generating facility is occasionally closed for maintenance or repairs, sometimes planned and sometimes unplanned. No generation source can be counted on to be available 100% of the time.
Wind farms are built in areas where the wind blows most of the time, but because of variations in speed, a wind farm will generate power at full-rated capacity about 10% of the time, and so on average throughout the year, the facility will generate 30%-40% of its rated capacity. That number is called “capacity factor.” Thus, if you hear that a particular wind facility has a capacity factor of 34%, it does not mean that the facility is producing power only 34% of the time; more likely, it’s contributing electricity to the grid 50%-80% of the time--just not always the full amount of power that the individual turbines are capable of producing pos software. A separate issue is the “capacity value” which is the percent of nameplate capacity that is typically available during peak load, based on statistical analysis of wind and load at a particular location.
Utilities — especially those that have experience working with the clean paper writers, renewable energy source — generally use wind to displace costly fuel and emissions. To some extent they also use wind to meet peak loads. For example, a utility in the Northwest, MidAmerican, added 20% of its wind projects’ nameplate capacity into its base-load calculation for the utility’s 2004 integrated resource plan—a clear indication many “wind-wise” utilities view their wind power facilities as generation resources that are able to provide a certain level of consistent power on a regular basis. Xcel Energy also has deferred coal and nuclear plans based on wind development. See online dating chat
