Idea for the future:
More complex energy scheme.
Currently, modules require X amount of energy and you must equip your ship with that much energy output in order to have a valid design.
The new system would work like this:
Ships generate energy every clock tick, which you may increase by adding power generators.
Energy goes into a ship's battery. You may add more batteries if desired.
When a module is in use, it takes energy from the battery.
If there is no energy in the battery, then the module can't do whatever it was trying to do.
So for a weapon, if it takes 5 energy to fire, that's what it needs in the battery in order to fire. If there's not that much there, it will have to try again next clock tick.
Shields might only use energy when recharging (or they might use energy all the time, until taken down, or they might use normal energy drain to charge and 1/4 drain when on but not recharging...)
Engines would use energy when moving but would use no energy (or might even generate energy) when not moving (e.g., Engine Y generates 2 energy/tick but uses 8 energy/tick when moving).
So the energy requirement on ship design technically goes away. You can have a full complement of weapons and shields with no reactors if you want, although you're going to have serious power issues once the shooting starts.
Extra batteries would help you go slim on the reactors with the idea that the ship can run on cheaper, lighter batteries when things heat up (for example, on a "front row" design that's meant to last about 5 seconds anyway). Batteries would also come into play when your reactors are damaged or destroyed.
In the fleet screen, there would be an addition control setting where you can set the ship's power management priority level: weapons, defenses, engines, other. Basically you would be telling it what order to take power from the battery every tick. If you select "other -> engines -> defenses -> weapons" then the ship will first use "other" equipment, such as nano repair and if there's any energy left it will use engines and if there's any energy left it will go to shields and if there's still energy left it will go to weapons. Or you might put weapons over engines because you'd rather shoot than move. Or weapons over defenses because you really only wanted to defenses to help you get into range to shoot.
I think that would be an interesting new system to think about.