I came back to NMS after a good while and before I start to really invest into my base i thought I have a look at few things in Creative mode. Here's my problem.

I've built a mineral extractor (1) and connected it to a couple of batteries and a couple of solar panels.
As long as the sun is up everything works fine but when the sun goes down everything stops. Batteries are being drained but nothing works.
Extractor uses 50kP and my batteries are charged with nearly 60000kP yet available kP shows as 0 !!
Powering smaller objects like Portal works fine.

Stage 2.

Ok, so I added more solar panels and batteries. 6 panels and 6 batteries total...
Fully charged batteries 45000kP each, so I have 270000kP stored in my network. I connected all batteries to just 1 extractor and it doesn't work. Grrrrrrrrr......

Nothing works until I connect the solar panel but then as soon as the sun goes down everything just stops....

I don't think I'm doing something wrong, am I?

Have you connected a Supply depot with a Supply pipe to the extractor, so that the produce has somewhere to be stored?

It wont work until you have, no matter how much power is being fed to it.

I built a Gas Extractor a few days ago (for the first time ever), and it was the same, would not run until a Supply depot was connected up.

Maybe they used to run without a depot, and a recent update has changed that behaviour?, idk personally, I only did the Gas extractor to clear the cue of things to do in a new game :)

Yes, I did connect the container. I managed to extract some stuff on a "daily" shift. ;)