The mounting pressure to decarbonize is causing many cities, states and companies to take a hard look at their electric power sources.

Though the shift is leading the electric sector toward more alternative resources, carbon-free ambitions remain largely ambitions. But six U.S. cities have reached their goals of not just a carbon-free power mix, but a 100% renewable one. Those cities range from less than 1,000 people to around 50,000 and stretch from Vermont to Texas to Alaska. What got them there?

Utility Dive traveled across four of those cities to learn about the people, the policymakers and the partnerships behind these accomplishments and what they can teach us about the power sector's growing transition.

From Rock Port, Missouri, to Greensburg, Kansas, Georgetown, Texas, to Aspen, Colorado, locals shared their insights on the political, technical and economic challenges to 100% renewable energy and how their cities became global leaders in the renewables revolution. Here are their stories.