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. Creating a power line that incorporated the zones into the existing grid, then, would allow the state to export clean electricity to its neighbours.
But the US electricity grid is highly concentrated in so-called regional interconnects, making the transmission of power from the solar-rich southwest to the cooler northeast highly challenging.
A proposal is pending in Congress, however, that would help the process along.
Senate Democratic leader Harry Reid, whose home state of Nevada neighbours New Mexico, has written legislation that would require the president to designate renewable-power zones across the US representing up to 1,000 megawatts of potential electricity.
Regional power agencies would have one year to evaluate the zones and choose the best locations for building new power lines. If no private companies can be found to invest in the transmission projects, financing for the new construction would then be available to the local governments where the zones are located.
"Utility executives like to say that we can't afford to build transmission lines that carry only or mainly renewably generated electricity," Reid testified at a congressional hearing this week on renewable energy transmission.
"They like to say it just doesn't pencil out. But if they say that, I just don't think they've really tried very hard to crunch the numbers."
