Sources for the benefits (economic and social) of wind and solar energy?

I’m writing a paper on the benefits of wind and solar energy, in both an economic and social context. Though I appreciate your personal opinion on its benefits, I would REALLY appreciate some possible sources to give me a start on the paper. Please keep in mind that I am not looking for a political discussion or opinions, this is for a graduate-level paper and I am to only write about the benefits of wind and solar energy – so sharing your personal beliefs about the negative effects of alternative energy does not interest me or anyone else and they will be ignored.