The world needs a new source of energy, an unspillable source.

Do you think that hydroelectric energy is a reliable energy resource for a safe and clean environment?

Ok! Hi. I have a research paper for English, and my topic is hydroelectric energy. I am having a hard time deciding whether or no hydroelectric energy is a reliable enregy resource for a safe and clean environment. To check it up, go t Wikipedia.I need help! :)
Thx