Seems the thread is a bit dead recently! I hope this is just because of the release of
Victoria 
In any case, are we agreed that the radioactive resource is too widely available and too little required?
It would be pretty simple to fix both problems. However, I think that rads should also be needed more in the weapons field (and thus for satellites)... but I am coming to the belief that it is in the area of satellites that solar powered weapons and launch systems should really shine. (pun intended) If we get rid of the auto-refuelling nature of planetary facilities, then the satellites will need a power source, and THAT is where solar will "shine"!