The fact that the wind does not blow all the time poses some challenges to the electricity sector, but these challenges are neither unique nor insurmountable.
Wind power can and does provide reliable electric service to consumers. Many utilities are already demonstrating that wind power can make a significant contribution to their electric supply without reliability problems.
According to the Department of Energy (DOE), nine U.S. utilities generated between 10 and 38 percent of their power from wind in 2009 (Wiser and Bolinger 2010). The largest user of wind power, Xcel Energy (which serves nearly 3.5 million customers across eight Western and Midwestern states), obtains 11 percent of its electricity from wind and plans to approach 20 percent by 2020.
Further, wind power already supplies 20 percent of the electricity or more for several areas in Europe: Denmark currently leads all nations with 20 percent wind penetration, and two states in Germany with a combined population of 4 million get 40 percent of their electricity from wind (Earth Policy Institute 2010).
Promising developments in storage technology have the potential to enhance reliability even more, though there are plenty of opportunities for wind power to expand without storage during the next 20 years at least.