I'll admit solar and wind are more attractive than I had thought, which makes me somewhat more optimistic.

That said, I think this analysis misses two important factors when it comes to impoverished countries. Otherwise, you would see more solar there. Developing countries have much lower standards when it comes to building a new power plant, so don't need to pay for sulfur scrubbers. The other factor is that unskilled labor much cheaper there. Solar and wind require much higher-skill labor as there is much more maintenance that needs to be done.