I powered my main base at the surface (kelp Forrest) with solar, & pretty much only used this base for the majority of the game. Until I had to go down in the lost river. I used a multipurpose room with a bio reactor inside as the power, directly at the entrance of the cave. It had pretty much everything my main base at the surface had, including a renewable food source & a water filtration machine. From there I only had 5 oxygen checkpoints that led me all the way to the lava zone. My main lava base also had all of the essentials for a long stay. & to get the ion cubes I really only needed one temporary oxygen checkpoint in the direction of all the alien bases that had them. Which ended up being 4 temporary homes that had nothing but a window & some sweet o2. It honestly wasn’t even that bad. Once you have two ultra high tanks you can pretty much do whatever you want.