> This might sound a bit like a buzz-kill, but I don't think fusion power is necessarily competitively cheap. 

Buzz kill on hn is fine so long as you back up your opinions with rational arguments and / or citations rather than simply sharing more of your opinions as ersatz supporting evidence.

  > I think it will be comparable to nuclear power with a ~ 10 times higher capital investment to build a fusion-plant. 

This is my biggest problem when talking with people about nuclear -- the conflation of fission and fusion. Saying fusion compared to nuclear is like saying diesel compared to internal combustion engine.

  > Already now solar is said to be cheaper then nuclear.

And solar means multiple things too - PVC and thermal, for starters. But who says this, and why, and [!?] where?

  > But nevertheless humanity should explore fusion since it is more or less the only significant power source not (indrectly) depending on the sun. 

Fission fits this bill too, but obviously is less desirable.

  > As far as I can see the funding of fusion research is at about the same level as particle physics which definilty does not provide any other than philosophical progress.

There's no benefit from particle physics other than philosophical?

Goodness.