How to make a forcefield system that's not solar powered

[BlueAmbulance1000]

I need help on how to make a force field system that's not solar powered. I need a non-solar powered force field system so my mine facility can be semi-secure. I have an idea of one with a pre-charged MFSU that was charged by solar panels, but whenever I change the time to night (solar panels removed) it looses power slowly. How can I prevent this?

[Valkon]

Well, obviously you'll need a form of generator that isn't dependent on the time of day. Perhaps a series of geothermal generators fueled by lava lakes would work? Maybe a cluster of standard generators supplied charcoal (or scaffolds if you like autocrafting) automatically via automated wood farming? Then again, a nuclear reactor might serve your energy needs well.

Or you could just install more solar panels and MFSUs so that there's never a shortage of energy but that's no fun.