aspen coloradoAs America shifts towards more renewable sources of energy, a few cities have stood out from the pack. Burlington, Vermont and Greensburg, Kansas were the first two cities in America to achieve 100 percent renewable energy portfolios, and on September 1st Aspen Colorado announced that it has joined their ranks.

The city made the announcement right after it signed a contract with wholesale electric energy provider Municipal Energy Agency in order to finalize the achievement. Aspen is now the third municipality to receive all of its power from renewable sources. They primarily get their power from wind and hydroelectric, with the addition of smaller supplies of both solar and geothermal.

The city has been working towards this goal for a little over a decade. 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.”

Their achievement was made possible both by the vision and efforts of the town, as well as by the extraordinary drop in the price of renewable energy in recent years. The cost of solar has continued to dive, and prices are 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, regulations set forth by the Obama administration (which limit carbon emissions from power plants) have been making energy resources like coal increasingly uncompetitive. More than one-third of American coal plants have closed in the past six years, and the new carbon regulations will probably stop any new coal plants from ever being built in the United States again.

Though Aspen is only made up of about 7,000 residents, Hornbacher told the Aspen Times that its achievement was of a greater symbolic importance. “We’ve demonstrated that it is possible,” he said. “Realistically, we hope we can inspire others to achieve these higher goals.”