Lately there have been numerous press releases stating, in somewhat ecstatic terms, that we are well on the way to transitioning the whole planet off fossil fuels and onto renewable energy. What invariably follows is a call for more investment in wind turbines and solar panels.
The first point here, is that wind turbines and solar panels do not equal renewable energy. They are a part of renewable energy supplies, but not the whole. Thus, it is not necessarily the case that success in renewables justifies more wind and solar spending. (It might actually indicate that other renewables should be funded instead!)
Invariably these press releases are vague about the actual proportion of world energy provided by wind and solar. The may quote ill-defined figures such as 'homes' powered, but never give any authentic engineering figures. Thus I've done a little research into how much energy wind and solar actually provide, and how much is spent on them... and it makes for thoughtful reading.
Links below to articles on this topic:
What else could we do with the money? A cost comparison of going 100% renewable with wind and solar, to other large humanitarian or public-spirited projects.