Last night I told you about several new wind farms in Pennsylvania that will be contributing electricity to the region's power grid. Nationally, wind energy is still a very minor player, representing less than one percent of energy production. Coal-fired plants produce the lion's share, slightly more than 50%.

Based on cost-per-kilowatt-hour, coal plants still produce energy less expensively than wind, although the gap has narrowed. Burning coal, of course, has its drawbacks, particularly that it pollutes the air. In fact, if the electricity generated by the new Pennsylvania wind farms were instead produced by burning coal, it would add more than 30,000 tons of carbon dioxide to the air each year. And carbon dioxide is the primary gas associated with global warming.

In contrast, wind power is renewable and clean. However, the places where the wind is consistently strong enough to produce wind energy efficiently and competitively are often far from where the electricity is needed the most. Nonetheless, recent advances in wind technology suggest to me that you'll be hearing more about wind-driven power in the years to come.