Xerium 42 is the primary energy source of your Space ship, the Weapons and the shields.
If you create a disc made of Xerium 42 and put it in high rotation at very low temperatures then the disc radiates enormous amounts of energy along the axis of rotation, like a microscopic Black Hole.
It has been found that Xerium 42 is a catalyst for a yet unknown form of energy into radiation (and as we all know – 42 is the answer to the ultimate question of life, the universe and everything).
This radiation can be converted into electrical energy or heat and is used as energy source for the Impulse Drive for sub-lightspeed velocities.
This "Free Space Energy" is – well – everywhere in the vacuum space which is not empty but filled with "Dark Energy". It is believed that Xerium 42 simply converts Dark Energy into a usable form of energy.
Unfortunately there is not enough space for a Xerium 42 reactor in your PEV for planetery expeditions so you must rely on battery power here and reload the battery in your ship from time to time.
Xerium 42 is a glowing mineral, can be found in smaller accumulations of ore lumps and is very easy to distinguish from other ores because of its bright red color.
Xerium is used up like fuel so you should always carry enough Xerium 42 to return safely back to your base!