"However, at its times of generation, about 84% of the wind power was surplus to local demand (White, 2004; Sharman, 2004) and had to be exported to the much larger power systems of Norway, Sweden and/or Germany, primarily to maintain stability of frequency and voltage in the Danish grid."

That's just sloppy management isn't it. The 4% figure is a twisted one, too. The other generators were also providing power at these times, who's to say it wasn't them that were over producing when the wind turbines were at full tilt? Why weren't other generators slowed down?

And although the future will see much more locally produced power, what's wrong with exporting it when you can? At least the nasty polluting generators in Norway, Sweden and/or Germany weren't having to churn out quite so much crap for a while.

And 20-35 years isn't all that long. I've been around longer than that and there hasn't been very large improvements in the systems in my lifetime. If using current renewable energy sources prolongs this period to 50-75 years then it has to be a better option than doing nothing. At least by adopting these now we have a better chance at finding an alternative, long lasting solution.