Hydroelectric is damn good, if you ask me. And fission. You can't get much greener than nuclear green. And don't forget about natural gas. Even though it ain't got no color, it's more green than coal and oil — especially when it comes from a bovine's behind.
You read right, we can (and do) get green energy — natural gas — out of cow crap (which does have a lot of green in it, by the way).
Fair Oaks Farm, a huge dairy farm in Indiana, is a poop power pioneer, converting doo-doo from thousands of milk cows into biomethane, a type of natural gas, which they then use to fuel their 42 delivery tractor trailers, and to provide electricity to run the farm and associated enterprises [ref, ref].
According to The Innovation Center for US Dairy's Erin Fitzgerald, a single cow's waste can power 150 homes [ref]. Even if that claim is 90% BS, harnessing (pun intended) that power could make foreign energy imports obsolete. There are over 9 million dairy cows in the United States, and if we average only enough power per cow (cowpower :o) for 15 homes (1/10th of Fitzgerald’s estimate), that's plenty of energy for our 133 million United States households [ref, ref].
Getting to that point certainly won't be easy or quick, but it would sure as heck beat having herds of ugly unreliable windmills jutting out of the landscape like giant sore thumbs. And it would be way better than planting seas of China-made solar panels.
Above all, if cowpower would help keep oppressive radical religious regimes and their terrorist pals from milking us dry, then all the crap would be worth it!