Telluric energy is actively manipulated by both stalwarts and mesmerists (in different ways) to employ their powers in the form of a personal store of the energy, called Inspiration by members of the Æon Society.
Technically, telluric energy doesn't exist, per se. It is simply a combination of two distinct forms of energy: psi and quantum. However, the scientific knowledge of the Inspiration Age is limited, so it will be another 75 years before quantum is discovered, and another century after that until researchers develop a viable theory regarding psi. In truth, mesmerists use psi energy, while stalwarts use quantum energy.