The fuel usage rates are:
Deuterium - 5 units per 16 seconds.
H-Fuel - 4 units per 16 seconds
MOX - 3 units per 16 seconds Gallic Fuel - 3 units per 16 seconds.
Promethene?
You should make it so a base admin can set how long until the shield automatically goes down, or at least keep it up. The shield goes down far too quickly. People could just heavy mortar a base, and it would do 500k damage. After a little while, they can attack again, with ANOTHER 500k damage. It's possible (although unlikely) that they could destroy the base in 1-2 hours, while the base owners could all be sleeping. That's a rough (rough) minimum of 4 heavy mortars an hour. That's 2 million damage. Without a doubt, they would be able to get more attack than that in. 'Oh but what about Weapon platforms?' All the battleship would have to do is go out of range, and return in 1-16 minutes, and attack again.