Engineer Energy Items
The primary point of engineering an energy item is to aid your teammates. You can use it impromptu, if your battle buddy needs a refill on their energy juice, or you could predict where your teammates might end up and place it there. It could be used as a defensive tool, placed in a crevice and marked with a spy bug for exhausted squad-mates, or be used offensively by placing it in a location that your team's invasion force will pass through.
I'm sure people can think of other crafty ideas. I was considering today how cool a strategy might be to purposely injure your ship so that passing enemies are "baited" into fighting a 1v1 with you. Then, you slowly lead them into an area you've drizzled with mines or first aid kits and other goodies, sending them into a fiery and woeful death. An energy item could be applied in this strategy as a way to get an advantage on your enemy.
One thing to decide is if the engineered energy item would be one-time use or forever respawning. Also, we would need to consider if the energy item was exclusive to the team that placed it or open to any player.
Personally, I'd lean towards one-time use energy items. I think forever-respawning energy items, or an "energy machine," kind of borders on "going against the level designer's wishes." Think about it: most strategies are dynamic and have an expiration date. If an energy machine kept rolling out energy items then the initial strategic need would eventually pass and it'd feel more like an item the level designer wrongly placed than a tactical short-term placement.
As for exclusiveness, I do think energy items should be exclusive to the placing team, because if not there wouldn't be much incentive in placing it. If I'm going to place an energy item then I want to know it will benefit my team and not the enemy. However, this might lead to unfair placement (like right in the enemy's base). That abuse could perhaps be balanced by allowing exclusive energy items to be shot down by enemies. One-sided energy items could also have interesting benefits in level design.
Thoughts?