Really, anything like gas, coal, oil, etc are ok power sources, but they aren't renewable. Soon, those materials will run out.
If you live in a place with a lot of sunlight, you could use solar panels. They use sunlight to make energy. And the best part, it's renewable, because the sun can't run out.
However, they can be quite expensive and require maintenance. First of all, stuff like dirt, moths, etc. get into the solar panels. If you have a whole field of solar panels, it will be pretty expensive. Also, they are really heavy, like 40 pounds each. But, people are creating robots that can put on the solar panels, and clean them. Some people from a few places, California is the only place I can think of because there's only like 3, have made these robots to do these things for them.
If you live in a place with not a lot of sunlight, especially in the winter, solar panels wouldn't work. Windmills will work great, but they require maintenance, too. It can be dangerous because people have to climb to the top to do some maintenance. (Dirty Jobs)
Watermills, which I know nothing about, are really great if you live by a river. A dam could work, too.
There's a game in Africa, I think it'scalled Socket (or something like that) that produces energy every time you kick the ball. It's like soccer, but it produces energy. This is good if you're an athlete, or if your kids like to play outside a lot. (I'm not sure what this website came from, one of my friends talked about it in science)
All of these things are natural and are renewable. Nuclear power is pretty good, but it's not natural because it causes a lot of pollution in the air, and it's not renewable. Overall, it just depends on where you live. If you live in like California or something, you could use solar panels. If you live where it's windy, use windmills. If you live by a river, use a watermill or a dam.
I really hope this helps you.