If you’ve been anywhere near a newspaper recently, you know that the Mississippi river has an unbelievable amount of kinetic energy, which lately it has mainly been using for wreckin’ stuff. It’s like an angry teenager who discovers he’s a superhero. But hydropower advocates are hoping to convince it that with great power comes great responsibility, cooking up plans to put enough small hydroelectric plants on existing dams to rival the total hydro production of the Pacific Northwest.
Of America's 79,000 dams, only 2,000 currently produce electricity. Many are small "run of the river" dams with only a 30 foot drop, but new technology has made tapping these smaller sources of power economically feasible. Other, more exotic means for harnessing the Mississippi are also in the works, including mounting giant turbines on the floor of the river.
All together, the proposed hydro projects on the Mississippi could only account for about 6 percent of the region's energy needs, so they're no panacea when it comes to replacing coal-fired power plants. That doesn't mean they won't be an important part of a portfolio of renewables — just that when you switch from burning hundred million year old dead sea creatures to a more sustainable model, you've got to diversify your sources of energy.