Despite the fact that yes, they do tend to use large amounts of energy, research is one of the most important things you will want to acquire. Without at least one research building of some sort you will never be able to research what you need to.
This includes Settlement defense and Levels 4 and 5. So unless you wish to remain at level 3 forever with zero hit-points when the pirates attack, I suggest investing in Research Buildings. The more the better, but at least one.