Several commenters questioned Friday's post on the grounds that the total amount of solar and wind power potentially available is insufficient to power modern civilization
This is incorrect.
Total available wind power available on land and near shore has been estimated at 72TW. This is close to five times current total primary energy consumption, and still more than twice as large as energy consumption in 2040 (extrapolating at the 2.7% growth rate of the last decade).
Of course, not all technically and economically feasible wind sites are politically feasible. Thus it's important that total incoming solar radiation is also very large. Top of the atmosphere incoming solar radiation is 174000TW. If we just look at the world's desert areas, they represent about a third of the global land area, itself about 30% of the total surface. Allowing 30% losses in the atmosphere over deserts, and throwing out something for Antarctica (a desert, but not a very useful one for solar power), we end up with something in the ballpark of 7000TW of available solar energy from deserts alone. This is hundreds of times larger than current civilizational energy consumption.
Therefore, constraints on our ability to utilize renewables are political and economic, not ultimate physical ones; there is plenty of renewable energy out there.