So, the calculations for the trip to the belt are WAY OFF.
Had the matter, seemed to be doing semi okay for energy, and it killed everything...
Think you need about 60-80% more matter than it registers
**SPOILERS**
When you travel you cannot harvest matter, so depends on the matter consumption of your station how much matter you need.
The calculation only takes into account matter for the engines.
Furthermore, when you get away from Earth there is no shadow anymore, but the sun shines less bright if you go far away. One has to account for that as well...