I have added a section on ERoEI near the top of the article, which speaks for itself.
Regarding variable wind and solar energy, the countries around the North Sea experience the same weather.
Interconnecting them will not reduce variability, as has been shown with 1/4 hour, SIMULATANEOUS, production data of various countries.
In fact, by adding these graphs, variability is increased, and because of interconnections, this variability can be dealt with by more gas turbine capacity inefficiently operating at about 75% output, while ramping up and down; more Btu/kWh, more CO2/kWh.
As you know, gas turbines become significantly less efficient at such operating conditions; large MW stationary diesel engines would better maintain their efficiency at such operating conditions.
NREL may be somewhat optimistic. Here are ACTUAL results of an outstanding offshore wind system
The Alpha Ventus offshore wind farm.
Germany’s first wind farm – owned by EWE, E.On and Vattenfall – the 60-MW capacity Alpa Ventus began full operation in April 2010 and on Feb. 21 it announced it had reached 1 terawatt-hour of generation. And it’s doing better than expected:
The average yield of the offshore wind farm in 2011 through 2013 was 253.14 gigawatt-hours per annum, exceeding the forecast yield by approximately 10 per cent.
The capacity factor of the wind farm of 48.1 per cent during this period is an outstanding result by international standards.