The Western United States is rich in renewable energy - both sun and wind. Harnessing this energy could help the nation reduce its carbon footprint and air pollution. The question is how to deliver this energy production to the densely population areas where it can be readily consumed. Modernizing and expanding the Western electric grid could require building 4,000 to 8,000 new miles of power lines by 2015, which would cost billions of dollars. Not rewiring the grid for renewable energy, however, would have an even greater cost.
Assignment Earth reports on greening the grid: