How did Burlington achieve 100 percent renewable energy?

Aired: 1/30/2015 | 0:06:55 | Clip
Burlington, Vermont, the state's largest city, recently became the first in the country to use 100 percent renewable energy for its residents' electricity needs. In a state known for socially conscious policies, the feat represents a milestone in the growing green energy movement. NewsHour's William Brangham reports on the implications for the country's green movement.