Renewable energy is on this planet and it still is most parts of the planet provide this kind of energy. The biggest flaw they have is the pollution they cause during their use and disposal environmental pollution leads to serious environmental problems and well known climate change but before investing, we need to analyze the market and be aware of the market environment as much as we are aware of the market environment. In the future the demand for electricity will increase five times which can be the only solution at the same time, the problem of greenhouse gas emissions can be solved.
Renewable energy doesn't emit pollution, I mean why would they advocate the use of it if it's can contribute to pollution? Maybe the manufacturing of some of them is probably bad but given how there's a lot of innovations in the field, it's unlikely they contribute that much, when was the last time you've seen a solar panels emit smoke and dangerous funes in the atmosphere?