The dirty secret is of course that the Danish power grid would be totally unusable without the base power provided from Sweden and Norway.
They almost suffered a catastrophic shutdown a year or two ago and the situation has not improved
The only dirty secret is that humans are happy to kill future generations as the effects of the oil economy will only minimally affect the people alive today.
Is that really a "dirty secret"?
https://en.wikipedia.org/wiki/Continental_Europe_Synchronous... exists for good reason.
That's like pointing out that Rhode Island isn't designed to be a self-sufficient grid.
The Nordic grid was designed to work as an interconnected system though - Danish wind exports and Norwegian/Swedish hydro imports balance each other out. Calling it a "dirty secret" makes it sound like a failure when it's actually the intended architecture. Denmark is frequently a net electricity exporter.