Here's an entrepreneur with a cool idea: The Green Microgym is one of the first fitness facilities in the world (they say) that will generate most of its own energy. But wait—before you scream "not another green business," check out their neat gym equipment here.

The Green Microgym, based in Portland, Oregon, will use the man power created by cycling and exercise other cardio machines to generate electricty that will run the facility. The machines are actually standard exercise equipment that have been tricked out with a device that harnesses the energy. The gym will also use solar panels on top of the building to generate additional juice.

While that's cool and all, the main question from a business perspective is whether their model is actually profitable and sustainable. According to their blog, they're having a hard time footing the intial $35,000 pricetag of the solar panels and their installation. But once that's paid for, the gym actually seems like it would be no more expensive to operate—perhaps even less so because of its low energy costs—than a traditional gym. The question is whether there are enough green converts to sign up and pay the one-time $100 fee, and subsequent $49 monthly dues. Aside from the machines affixed to the cardio equipment, the gym has most of the standard amenities you could expect at your local 24 Hour Fitness—yoga, stretching room, televisions, and more.

What do you think? Would you invest in the Green Microgym?