We are been inundated by claims from NGOs like WWF and Greenpeace, or energy-expert auditing firms, that a World relying on Renewable Energy sources is feasible in the next 40 years. I happen to believe that ExxonMobil, the big bad energy company, is better qualified to offer opinions on the matter.
There is a recent energy outlook report by ExxonMobil, which may be found on its site, or here.
We are used in thinking of ExxonMobil as a US-based oil company. The summary of ExxonMobil's report is that future growth is in Asia and it is powered by coal.
The report also includes a chart that confirms most other published information on the cost per kilowatt-hour of electricity. Coal-generated electricity is the least expensive. Solar electricity is the most expensive. Wind power (with the necessary cost for backup) is comparable to, or more expensive than, nuclear. If coal were to taxed with a tax high enough to double its cost, it might become more expensive than either wind or nuclear.