Wiktionary
n. (context legal English) Power that is retained by the government after other powers were distributed to other authorities in the course of elections or by the process of delegation.
Usage examples of "residual power".
There was evidence of residual power remaining in the derelict, and of several pockets of atmosphere of various densities, but no sign of life.
Art's logic was wearing him down and what with the purely residual power of Ukko's cosmic brilliance.
Nikko wrote an address for home and fled before the atrium's residual power ran down.
With the residual Power of the quan-iron spheres to aid us, we could just barely preserve the same evident force level as before.
Some deep buried things from the past have a residual power supply so the looter could broadcast his warning before he died, and we have a crack at the codes, but just lighting a fire anywhere on the surface would ring alarms and bring the Titans.