Hello,
I've recently started playing and the idea of a base built into the rock really appealed to me, so I mined out some space and began builiding stuff "inside" the rock. Since the no-roof zones were added recently, I hoped I could create my solar generator block inside the rock as well, removing the roof on top to make them actually able to produce power, but that doesn't work since the rock roof is considered too thick (I guess). What's a common solution to this problem? Simply building your solar generators outside? I kind of hoped to be able to build the entire colony inside the rock :/
Thanks in advance
Thick rock roofs cannot be removed. You have to run power lines from outside the mountain, unless you discover a steam vent under the mountain somewhere.
As Thunder1 noted, if you're lucky enough, you may find steam underground, essentially allowing you to go completely underground.
I don't know how common it is, I've played say 5 games where I've mined out any meaningful amount of stone, and had it happen once. So in all likelihood, most maps may have vent _somewhere_, but with something like a radar/sonar/heat detector, you need to do a look of digging.
Because I enjoy building "perfect" bases, I tend to restart maps until I get a vent near a mountain where I want my base, but still, one need power lines from the outside.
You might be lucky enough to break through into a newly discovered open area. As long as you avoid walling it (or declare it as a no roof area) you can place your solar panels and grow areas in it.
Otherwise, you'll be reliant on location of steam vents, or find a good choke point to start your base that allows you to put in some solar that can be defended easily.
My own underground base method is to build 20-30 batteries and deploy ~15 solar panels between raids, then wall off the base at a choke point during raids. This provides more than enough spare power to run the base for many days before a recharge is necessary (of course, most of the batteries have to be disconnected from the grid because of the risk of explosions). I haven't tried this in Alpha 2 yet, though, so your mileage may vary.