backupPowerSource

Given a predicate that represents a relationship or action between entities, generate a one-sentence description explaining its meaning.  
# Instructions
Focus on describing the relationship, not the entities themselves. 
# Response Format
Begin the description with \' Indicates...\'

Predicate: backupPowerSource

Indicates that one entity serves as an alternative or emergency source of power for another entity when the primary power supply is unavailable or insufficient.