10 Countries With the Largest Capacity of Wind Energy

The U.S. Department of Energy recently announced it was embarking on a two-year collaboration with six leading wind-turbine manufacturers to advance wind-power capabilities. Such an effort is necessary if the department is going to reach its goal of growing wind's total share of the U.S. electric supply from about 2 percent to 20 percent by 2030. If that happens, we could "eliminate 7.6 cumulative gigatons of CO2 by 2030 and 825 million metric tons in 2030 and every year thereafter," according to the DOE.

Reading that, I wondered where the United States ranked with other wind-energy-producing countries now. Below is a list of the top 10, ranked by the total capacity in megawatts installed by 2007.

But first, to put the numbers in perspective, some thoughts on megawatts. MWs are commonly used to rank energy generation at its peak load. In general, it takes an average number of MWs to power a certain number of homes in a given year.

But the number of homes powered varies depending on two big factors: location and type of generation. Homes in the South consume way more electricity to power air conditioning units and pool pumps than homes in the North. And a coal-fired power plant runs on average at about 75 percent of its peak potential. Wind is intermittent and runs on average at about 30 percent of peak potential. Unfortunately.

According to the folks at Utilipoint, an energy consulting firm, 100 MW of wind energy coming from a wind farm that operates at an average 30 percent capacity factor would power 35,000 homes in the Northeast and 18,000 homes in the South. "In other words," they say, "each megawatt of rated capacity for a wind farm in the Northeast generates the equivalent amount of electricity consumed by 350 homes in the Northeast and 180 homes in the South."

Based on that, I did my own little calculation about how many homes the wind energy from the countries below would power.

By the looks of it, we have a long way to go toward making wind a bigger energy contributor -- not just here, but everywhere in the world.

Source: Stefan Gsanger, secretary-general, World Wind Energy Association