Wind power is the fastest growing renewable electricity source in the world. In areas with good land-based resources, wind has reached cost parity with fossil fueled electricity generation. According to the Global Wind Energy Council (GWEC.net), the capacity of installed wind turbines worldwide passed 480 GW in 2016. In the United States, Texas led in installed wind capacity with over 20 GW. Wind provided more than 30% of electricity generation in Iowa in 2015. Turbine designs continue to advance to allow higher hub heights, accessing greater wind resources. Improvements in turbine control systems, wind forecasts, and grid integration are supporting increased grid penetration levels. Although well behind land-based wind in total capacity, offshore installations are expanding rapidly, led by northern European countries including the United Kingdom, Germany, and Denmark.