This is the format used by most areas. It has a four-digit area code (after the initial zero) and a six digit subscriber number, and is known as 4+6 format. These area codes were changed by adding a 1 directly after the initial zero as a part of PhONEday in 1995. Just short of 581 areas use this format, and the area codes range from 01200 to 01998.
For calendar year 2016, wind power in the United States amounted to 226.5 terawatt-hours, or 5.55% of all generated electrical energy. As of January 2017, the U.S. nameplate generating capacity for wind power was 82,183 megawatts (MW). This capacity is exceeded only by China and the European Union. Thus far, wind power's largest growth in capacity was in 2012, when 11,895 MW of wind power was installed, representing 26.5% of new power capacity.
In the real world, the wind varies constantly. Actual wind power density at most sites can range from 1.7 times to 3 times greater than that calculated from only the mean wind speed. For a typical 15 mph site in Iowa, the actual average wind power density is about 400 W/m2.t the first location the wind always blows at 15 mph, giving a power density of 189 W/m2. At the second site the speed fluctuates. The wind is at 10 mph half the time (power density = 56 W/m2), and at 20 mph the other half (power density = 448 W/m2).