Editor's Note: Watch "Green Solutions In Focus," an hour-long special hosted by CNN's Tom Foreman, on Saturday April 24 at 3 p.m. ET on CNN, and check out the In Focus Facebook page.
(CNN) -- Golden, Colorado, got its name because of its role in the Gold Rush, but these days the land of gold has gone green.
As demand grows for clean energy, scientists are compiling data in this Rocky Mountain city just outside of Denver, looking for a 21st century kind of discovery.
"Golden started with gold mining but now we're mining another kind of gold from the sun," said Ron Judkoff, program manager at the National Renewable Energy Laboratory.
"We're completely dedicated to green, sustainable technology."
This year marks the 40th anniversary of Earth Day, and the scientists at NREL are working to make energy cheaper, more efficient and more reliable -- as well as greener.
In the Green Solutions in Focus series, CNN photojournalists look at solutions to address the issues affecting the planet -- and the environmentally conscious people who are trying to make a difference in their neighborhoods and beyond.
In Vermont, dairy farmers participating in the Stoneyfield Farm Greener Cow Project are experimenting with methods to reduce bovine greenhouse gas emissions.
Cows' silent burps release the potent greenhouse gas methane, said Stoneyfield Farm's Nancy Hirchberg. By increasing the Omega-3 fatty acid in their diet, the cows produce less methane and more nutritious milk.
In New York's Westchester County, Ston Barns Center is finding it can make cozy bedding for their Berkshire pigs by recycling their cardboard and paper waste.
"We have a lot of paper products that come in ... so we were able to actually start shredding that and using it for bedding," livestock manager Craig Haney said.
"It's a way for the pigs to have a good experience while inside and reduce our carbon footprint by taking care of a lot of cardboard that's coming in and ending up with some great compost in the end. Seems like a winner for everybody."
In New York City, Brooklyn filmmaker Garret Fannelly is using energy-efficient lighting, digital media cards and recycling to reduce his group's effect on the environment.
"My hopes for the film industry is that it continues on this path of greening all their sets," he said.
And at Washington, D.C.'s School Without Walls, the Alliance to Save Energy is teaching students simple steps to make their homes more ecofriendly and energy efficient while inspiring them to consider environmental careers.
"I'm finding in my own life, I'm educating people around me," one student said. "Bringing some of the things that I learned in class today to the administration could help the school for years to come."
More stories in the Green Solutions in Focus series include:
More In Focus series: