Watch out everybody, turbines are growing. According to the 2009 Wind Technologies Market Report (WTMR) released this August by the US Department of Energy, a turbine’s average nameplate capacity (the maximum output a turbine can produce), hub height (distance from the ground to the spot where the blades converge), and rotor diameter (diameter of the circle traced by the blades as they rotate) have all increased during the past year. The average turbine now stands 258 feet tall with a rotor diameter of 268 ft. It can also produce 1.74 megawatts (MW) of power under near-ideal conditions, up from 1.66 MW in 2008. These are encouraging signs; the larger the turbine, the more efficient it will be at low wind speeds. Turbines that can produce at low wind speeds are more reliable and thus make it easier to integrate wind into the electrical grid. The manufacturing and engineering skill needed to build big is also indicative of wind becoming more deeply entrenched in the American energy industry.

Furthermore, it’s not just the turbines themselves that are scaling up; the size of an average wind farm is increasing as well. The WTMR finds that the average wind farm constructed in the US in 2009 had a capacity of 91 MW, higher than any other year on record except for 2007. The larger the average capacity of a US wind farm, the more viable wind becomes as a major factor in the country’s energy mix. Also, larger wind farms are more affordable because of associated economies of scale, and more reliable because they have a lower variability of electricity production from high-wind to low-wind periods.

According to the WTMR, the total installed wind capacity in the United States is growing all the time, at an exponentially faster rate as time goes on. An especially exciting statistic is that the U.S. has the potential to install 300 gigawatts (GW) of wind capacity if we build an interstate transmission network. Even though the vast majority of that capacity is undeveloped, it’s still a promising number. It means the Department of Energy’s goal of producing 300GW from wind by 2030 is firmly within reach. It also means that 2011 and 2012 are primed to be huge years for bringing more wind energy on line. All of this points to a reassuring bottom line: our energy future is looking much cleaner.