This disclosure relates to a wellbore electrical isolation system and method. The system may comprise an electrically conductive tube, an insulating layer covering at least a portion of the tube, an electrically conductive centralizer, electrically insulating confinement devices, and/or other components. In some implementations, the system may be configured to electrically isolate one or more sections of an electrically conductive well tubing string from an electrically conductive wellbore casing. In some implementations, a well may include one or more wellbore electrical isolation systems. Electrical isolation of the tubing string from the casing may facilitate powering one or more electrical loads disposed within the wellbore via a coaxial transmission line formed by the casing and the tubing string.