This story initially appeared on Grist and is a part of the Local weather Desk collaboration.
In 2014, Burlington, Vermont, the birthplace of Ben and Jerry’s ice cream and the stomping grounds of Senator Bernie Sanders, introduced that it had reached an power milestone. Town of 42,000, which hugs the shore of Lake Champlain, produced sufficient energy from renewable sources to cowl all its electrical energy wants. Burlington, town authorities proclaimed, was one among America’s first “renewable cities.”
Since then, Burlington has been joined by Georgetown, Texas, Aspen, Colorado, and some different small cities throughout the nation. And although some cities have a head begin—Burlington advantages from an enormous quantity of hydroelectric energy and ample wooden for biomass burning—many who depend on fossil fuels for energy are becoming a member of in. As we speak, greater than 170 cities and cities throughout the U.S. have promised to shift their energy provide from coal and pure fuel to photo voltaic, wind, and hydropower. St. Louis, which presently will get solely 11 % of its energy from renewables, says that it’s going to run purely on renewables by 2035; coal-dependent Denver has promised to do the identical by 2030.
“Cities are setting these targets and striving to go from a really small proportion of renewables to 100% on an especially formidable timeline,” mentioned Lacey Shaver, metropolis renewable power supervisor on the World Sources Institute, by way of electronic mail. “It’s an thrilling time for metropolis power work.”
However are 100% renewable cities truly … 100% renewable? The fact is a bit sophisticated—and it reveals the challenges of true, “deep” decarbonization of electrical energy in america.
First, shifting to scrub electrical energy doesn’t imply {that a} metropolis zeroes out its carbon footprint—residents may nonetheless be driving gas-guzzling automobiles or heating their properties with pure fuel. Even most claims of working on “clear” electrical energy include caveats: What cities truly imply is that they buy sufficient electrical energy from wind, photo voltaic, or different clear sources to steadiness out the ability that they use over the course of the 12 months. For locations full of renewables, like Vermont, that’s not such an enormous deal. However in different areas, a metropolis may not be utilizing all renewable electrical energy in real-time. Even when the solar isn’t shining and the wind isn’t blowing, electrons nonetheless should be flowing via the grid to maintain the lights on. And in the meanwhile, quite a lot of that extra constant power comes from non-renewable sources, primarily pure fuel and coal.
“There’s actually no metropolis that operates as an island in electrical energy,” mentioned Joshua Rhodes, a analysis affiliate on the College of Texas at Austin. “You’re going to be related to a bigger grid.” There’s no such factor as “fossil gasoline electrons” and “renewable electrons”—all energy mixes collectively as soon as it reaches the grid. Which means even a 100% renewable city may, every so often, be sourcing its electrical energy from fossil fuels. Due to this, Rhodes says that targets to run purely on renewables are extra like accounting mechanisms than a pure description of a metropolis’s power sources.
In the meanwhile, this isn’t an enormous downside: Most cities have a protracted strategy to go even to get to that stage. The U.S. electrical energy grid remains to be over 60 % powered by fossil fuels, and most cities get solely round 15 % of their energy from renewables. When municipal governments purchase renewable power—even when they’re nonetheless hooked into the bigger grid—they add to the demand for wind and photo voltaic installations. However in the long term, consultants say that this technique is just not going to get the nation totally off fossil fuels.