Board Thread:Questions and Answers/@comment-137.200.0.112-20180509190813/@comment-454133-20180509192109

Actually Huge Ships gain energy when moving. Moving 1 forward gives you 3 energy, while faster speeds lower the amount of energy you generate that turn (you're focusing your generators on powering your engines, so you have less energy to spend on other systems).

Weapons and upgrade cards are one way you spend energy. Huge ships generate energy each turn when they move, then assign some of that energy to upgrade cards (and often keep some on themselves, depending on what you have equipped). Some cards will let you spend energy during combat, others during other phases (read what the card says). Some cards require you to spend the energy assigned to that card (that card can't spend energy from anywhere else, and it can only have a certain amount of energy assigned to it, to keep things balanced), while others spend energy assigned to the ship.

Actions can spend energy as well, e.g. regenerating your shields. And some upgrade cards trigger on your actions (or attacks), letting you spend energy for additional effects.