Aspen, Colorado becomes 3rd U.S. city to run entirely on renewable energy

The number of American cities that run entirely on renewable energy is growing.

Last week, the city of Aspen, Colorado declared it had become the third municipality to receive all of its power from renewable sources. Aspen’s energy portfolio now primarily consists of wind power and hydroelectric, with smaller contributions from solar and geothermal.

The announcement came after the city’s decade-long effort to shift toward renewable energy. David Hornbacher, Aspen’s Utilities and Environmental Initiatives Director, told the Aspen Times that “It was a very forward-thinking goal and truly remarkable achievement.”

Burlington, Vermont and Greensburg, Kansas were the first two cities to achieve all-renewable energy portfolios.

Aspen’s new energy portfolio was made possible by the extraordinary drop in the price of renewable energy. The cost of solar has plunged in recent years, and the price is expected to drop below $0.50 per watt within a few years. Wind power has also become far cheaper than it was just a decade ago.

In addition, new regulations from the Obama administration that help internalize some of the pollution costs of fossil fuels are making energy sources like coal increasingly uncompetitive. Already, more than one-third of American coal plants have been shuttered in the past six years, and the new carbon rules make it quite possible that no new coal plants will ever be built in the United States.