Yes you can get small water paddle wheels. With a strong current you may get 5 watts out of them. They are pretty inefficient. Small scale water turbines are more practical. There are environmental impacts for them though. You need enough flow or pressure to produce enough power to be practical.
Environmental concerns on wend power mainly center around birds colliding with the blades. Small wend plants do work. To displace enough wend to have a large impact on fossil fuel consumption you need a lot of big turbines though.
Solar photovoltaics is practical for remote villages. Enough energy can be produced to run a 2 way radio and some nighttime lighting for example.
Transport with power lines over the road have been around since the end of the 19th century. Hear in Philadelphia, we have electric trolleys and light rail.
For people on the grid, I strongly agree that conservation is by far the first option.
Bruce
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