[gloryhound]

I have added just this function to my custom blend of the game, however I used a Reactor piece, didn't make it mandatory. What I did do was removed all but a basic amount of "supply" from ship engines. Changed the ships all over to a fuel based system. Instead of Ion Engines for lvl 1 you get Solar Sails which have 10 supply takes no supply to use and 0.5 movement, and because it's classified as a "engine" the AI will use it. I also redefined supply storage as fuel tanks which are fragile and only hold a small amount, only in late game can you forgo a reactor and have any range. The principle is that the reactor uses your fuel to improve efficiency of the fuel, much like a real ship would use fuel to generate thrust and energy. so just modify AI ship building priorities to include a minimum of supply storage and viola.
I liked this especially because it made my very first ship feel very low tech, with solar sails that were fragile, large and slow, but free to use.