Trelvestian Essentia is a Tournament Server goal. In this type of tournament server the goal is for an alliance to capture and control all four of the Trelvestian colonies. The first alliance to do this gets listed in the hall of fame and may get other prizes as well.
There are several rules about this type of server that are different than an Empire Server. These are the known list of changes:
The Trelvestian Sveitarfélagi have discovered the only sources of essentia in the Expanse. They control all five veins. There is no hope of taking their home planet as it is too well defended, but if someone can capture and control the four Trelvestian colonies, then they could be the one true power in the Expanse.