Make computers use energy.

Give devices the ability to declare how much power they draw. Maybe do this in the provider, to make it clear this must be a constant value. VM then sums up the costs and consumes that per tick.

When energy runs out, VM will power off directly.

Will the vm power off safely or just kill the execution thread/state?

Not sure what you mean by "safely", but the intent is to have it power off directly, as if pulling the plug.

K, Maybe there could be a battery component so the user can program the pc to send exit signals to all running programs and then shuts down the computer safely.

Oh, to answer to your remark: for now I expect it to remain necessary to have some other mod provide power. One of those will likely have some energy storage block, and those it will be possible to get storage readings from. So what you mention should be possible.