I still laughed a fair bit through this, which is really what I look for a comedy show to do.
I thought Rimmer's Parents were 7th Day Hoppists but I must be mis-remembering that.
No, you're right they were previously described as Seventh Day Advent Hoppists.
Why didn't they just use power from Kryten? Or indeed apples - anything that has acid...
Now you say it, yes, Kryten would make an obvious power source.