Britain to build Europe's first nuclear plant since Fukushima

[caraher]

14. The credentials required are English language comprehension

You don't need a degree, real or imaginary, to discover kristopher is right about what NAS reported in 2009. After discussing many ways to get to 20% renewables quickly, and potentially following that up with a further substantial increase the NAS report goes on to say

Integrating renewables at a much greater level so that they account, say, for more than 50 percent of U.S. electricity generation would require scientific advances and major changes in electricity production and use. It would also necessitate the deployment of electricity storage technologies to offset renewables’ intermittency. More details on deployment are available in Chapter 6 in Part 2 of this report, and an extensive discussion is presented in the panel report Electricity from Renewable Resources: Status, Prospects, and Impediments (NAS-NAE-NRC, 2009a).

So far from saying 20% is a cap, they actually say 50% is NOT a cap, but something that would require a lot of changes. No surprise there. And this is mostly engineering and economics, not physics...