Do you really think solar and renewable energies are a good investment?

Yes. Solar energy and other forms of renewable energy (such as geothermal) will become cheaper as people continue to invest in them. When people invest in them, this will drive down the cost-- as it already has over the last few decades. This has a snowball effect: the technology becomes increasingly usable, cheaper and convenient.

Look at changes in satellite dish technology: twenty years ago, they were gigantic wieldy things only people in the country bought. As more people invested in these, though, the cost went down, the technology got more compact and now they are everywhere-hardly noticeable. Recent developments indicate that this is becoming true of solar energy, too.