There are downsides to all forms of renewable energy. Water powered energy ends up destroying the local ecosystem by ravaging the migration patterns of fish, for instance.

I did some research on this, and I found that regardless of what energy source you use, if you use it past a certain threshhold, there are negative effects.

With solar energy there is the real estate cost. Solar panels take up a lot of ground, and force everything underneath it to live in the shade, basically.

I think the bottom line is we must be more conscious of how we use our energy and use less.