I am preparing a presentation on renewable energy sources. Can you provide me with a brief overview of the main types of renewable energy and their benefits? Your response should contain at least 5 sentences. Highlight at least 2 sections in your answer with markdown, i.e. *highlighted section*. Include keywords *sustainable*, *environmental impact*, *cost-effective*. At the end of your response, please explicitly add a postscript starting with *P.S.*.
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