Think of a power line as a highway for electricity. How easy would it be to force a highway to only allow hybrid cars on the road?

Therein lies the dilemma for US renewable energy transmission officials such as Lisa Szot, executive director of the New Mexico agency in charge of putting more clean power into the grid.

Szot's goal is to build new power lines in her state that carry as much electricity as possible from renewable sources rather than existing coal-fired plants – the energy equivalent of kicking inefficient Hummers off a local highway.

To that end, her team has zeroed in on five renewable energy zones where the state's solar and wind energy is concentrated. ... Read full article