Wind is a fairly abundant, widely distributed potential source of clean energy. Most commonly it is harnessed by a wind turbine and converted to electricity. It is estimated that wind power could account for as much as 72 TW of energy world wide, though it accounts for less than 1% of current electricity generation. Some countries manage to produce significantly more, such as Denmark which generates nearly 20% of their nationwide energy from wind.

While wind has wider distribution and better availability throughout the day compared with solar, it is intermittent. Typical wind farms generate energy at about 20-40% of their theoretical maximum output. The ratio of actual production to the theoretical max is called the capacity factor. For example, a 1 MW wind turbine with a 35% capacity factor will produce 0.35 MW on average. This still leaves the need for either overproducing and storing energy during peak product or reverting to an alternative energy source during low wind periods.

In addition to intermittency, there are some environmental concerns for wind power. While no greenhouse gases are emitted during the operation of wind turbines, there is some concern that due to the intermittent nature of wind generation, the quick-start back up generators may be more polluting than the standard fossil-fuel plant they are replacing. Also, wind farms require large, unobstructed areas of land. There is also a concern that these wind farms have a negative impact on wildlife, especially birds and bats. While some studies have shown significant impact to bat populations in especially sensitive areas, most studies show that the impact on birds is fairly negligible. Another potential concern is whether noise produced by wind towers at sea could pose a risk to ocean mammals.

It doesn’t seem likely to me that wind can solve all of our energy generation needs. It does seems like a good complement to other alternative energy sources. Perhaps a combination of well placed wind farms and solar farms could meet most of the world’s energy needs. It seems like we would still need to make some major improvements in energy storage and transmission for this to come about. I certainly hope we will all start to feel the winds of change…