This semester, in an effort to rise to the challenge of global warming and decrease their personal footprint on the globe, eight high school juniors decided to pull the plug on their own dorm and live off the grid for a full semester. The students are attending Chewonki Semester School, a high-school program where students live in close proximity to their natural environment and study a curriculum which emphasizes sustainable living.

Their dorm is called Gordy Hall, and the eight girls that live there are affectionately known as the Gordy Girls. Both are uncommon.

Let's start with the dorm: work on Gordy Hall began in the fall of 2006, and right from the start, it was clear that this dormitory cabin would be different. It was built with the help of the semester students, and the cabin was designed to be as green as possible, incorporating features such as superinsulation using non-toxic shredded denim (recycled blue jeans), passive solar design, and light tubes for natural daylighting. The only heat for the cabin is a small woodstove, which the students supply with cordwood.

But all these green features hide the real innovation of the cabin, something known as the Hubert system. The Hubert system is a bicycle-powered generator which, when ridden, can supply the cabin with electricity. This allows the occupants to disconnect from the grid entirely, by riding a bike to electrify a battery bank and thereby the cabin. The Hubert system also includes a small photovoltaic array on the side of the cabin, which helps to charge the batteries on sunny days.

This is the first semester that the occupants of Gordy Hall have been able to spend an entire half a year off the grid. But it hasn't been easy for the eight students living in Gordy (the Gordy Girls) to pull off this feat. A mere five-minute ride on Hubert's bike-powered generator is exhausting, and the girls ride the bike for 35 minutes every day.

A schedule for who would ride the bike and when, a system of conservation of electricity, and finding time to do all this amongst their already busy school day - these were just some of the obstacles the girls had to overcome not just once, but for a full semester.

It would not be an exaggeration to say that the scale of their effort and perseverance is staggering. But their motivation for doing all this - to merely live more simply, more lightly, on this planet - this is the truly inspiring part.

Listen to the girls' story. . .