Board Thread:Questions and Answers/@comment-118.210.135.133-20130419223818/@comment-10703376-20130719021655

It adds a negative side-effect to using the extreme-power weapon. It uses little energy to shoot, so there must be another negative effect. Most modules have this:

The Teleporting module uses lots of energy.

The Flight Control module is very finnicky.

The Walking Boost module uses energy just to merely walk.

All modules have their drawbacks. The Railgun has a kickback. Simple.