Zero-point Energy

Zero-point Energy (ZPE) is a predicted minimum energy state for all objects to possess. For example: the pendulum mass on a swinging wire will always have an energy greater than $E_{0}={\bar {h}}\omega$, no matter how much energy you take away from the system. All objects have a ZPE that can be exploited, even if it is not yet practicable to do so.

Zero Point Energy