After fans have gotten their ya-yas out at the ubiquitous outdoor concerts that fill NYC summers, one familiar ugly sight prevails: garbage cans overflowing with bottles, cups and plates, surrounded by a vast expanse of litter-strewn grass or concrete. But at CitySol 2007, Solar One’s clean-energy music and art festival, you won’t see any trash—if the organizers can help it.

“We’re trying to make sure that nothing is garbage, that everything is recyclable or biodegradable” to meet the goal of “zero waste,” says Jenn Su, special projects coordinator for Solar One, a not-for-profit that educates the public about environmental issues, particularly those surrounding energy. In its third year, the CitySol outdoor festival has ballooned from a one-day concert at Stuyvesant Cove Park on the East River (where Solar One’s office is), to a four-day extravaganza that has branched out (for one of its nights) to South Street Seaport.

CitySol, with its solar- and biodiesel-powered stage, is the first of Solar One’s summer arts festivals (the others focus on film and dance), and opens Thursday night at 6 p.m. with a trio of local bands. Dragons of Zynth’s heady mix of Afrobeat, punk and electro-psychedelic soul and their intense live shows have helped them rise through the ranks of the NYC music scene. DJ Mistakes, with his bicycle-powered turntablism, and electro-post-punkers Brightside open.

For Friday evening’s show, Solar One teamed up with the Seaport Music Festival for CitySol’s only off-site event, which happens further down the East River at the South Street Seaport and include experimental art-rockers Menomena (from Portland, Ore.), who’ll headline, swing unpredictably from stentorian to subdued, creating complex rhythms and intricate layers with heaps of instruments.

Saturday, the all-day music marathon begins at 1 p.m. Brooklyn noise-rockers These Are Powers, who recently toured in a biodiesel bus, performs mid-afternoon, followed by another local act, the goth-country O’Death; Baltimore’s multi-talented electronic wizard OCDJ (aka Dan Gaeta); and a pair of Montreal bands, the angular guitar-slinging Land of Talk and dreamily psychedelic The Besnard Lakes. Brooklyn experimental-noise favs Les Savy Fav cap off the evening.

With CitySol, Solar One aims to show New Yorkers that environmentalism doesn’t have to be a back-to-the-land movement: It can (and should) be an integral part of city dwellers’ lives—from the food they eat and the power they use, to the products they consume. Lucid Food, which specializes in local and organic items, is catering the festival with a special menu focusing exclusively on food from farmers and artisans within a 100-mile radius of New York City.

Although Solar One will provide biodegradable utensils, most of the menu items will be finger foods. And anyone who brings a reusable cup gets a discount at the bar.

To entice do-gooders to sign up for ConEdison Solutions’ green power from regional wind and hydropower sources, Solar One’s offering free Brooklyn Brewery beer to those who make the switch. On Saturday, the festival will include a green product marketplace, and the festival closes Sunday afternoon with workshops on making your own biodiesel and composting in the city. Throughout CitySol, environmentally-themed, site-specific art installations—many with their own sources of green power—will fill the Solar One space.

Pulling environmental issues into an arts context seems like a perfect fit to Su.

“The culture here is so strong, sustainability should be a cultural project just like art and music are,” Su says. “It all goes together hand in hand.”

July 12-15, Solar One, Stuyvesant Cove Park, 2420 FDR Dr. (at 25th St.), 212-505-6050; various times, free.