It began five years ago, when two best friends started worrying about the health impacts of pollution. At the time, they were 12.
"Half a thousand kids die every year because they have asthma attacks. Kids actually lose their lives because of how we produce energy," says Diego Arene-Morley.
So Diego and his friend Walter Lynn looked for ways to promote cleaner energy. First they tried energy-efficient light bulbs.
"We bought $3,000 worth of light bulbs wholesale and sold them for the same amount of money we bought them for," Walter says.
But the light bulb business was tough to sustain. So the boys started encouraging their Mount Pleasant neighbors to go solar.
"They contributed in really real ways, whether it was by inspiring people, distributing flyers, or putting together graphs, or analyzing information," says Walter's mother, Anya Schoolman.
She says the adolescents' energy propelled the project.
"In Mount Pleasant, every single house has two flights of steps. I would have given up at the very first half block," she says. "But I had two strong 12-year-old boys going up and down," she says.
Plus with two idealistic teenagers watching, the grownups felt they had to stick with it: "They can't see us fail, they can't see us give up," Schoolman says.
And they didn't. These days, the Mount Pleasant Solar Cooperative includes more than 350 members. And the city has become friendlier to solar power, with new rebates and incentives.
Diego lobbied hard for the most recent bill, the Distributed Generation Amendment Act, which regulates solar credits, or SRECS, produced by people who have solar panels.
"The bill forced local utilities to buy local SRECS that were generated in District boundaries, and it makes it that utilities had to buy more solar power as part of the green power they already have to buy," he says.
Diego admits he's missed school once or twice to testify at council hearings, or participate in protests, but he says it's worth it.
It's more engaging than doing just some of the more routine things of a teenager, just sleeping all day," he says.