What powered Voyager's holodecks? They often talked about Voyager's hologrid as an "independent subsystem", but they never showed what generated the power, like an ore processor or whatever. And those episodes where main power is offline but the holoprojectors are still operational or vice versa show the power systems to be incompatible, as otherwise they could share and ration energy by using transformers to convert the differing voltages and the system wouldn't be, as stated, offline.