A first completion system with electrical isolation, electronics, and a first side of a coupler is installed in a borehole drilled in a geological formation. A second completion system is installed in the borehole after installation of the first completion system. The second completion system has a second side of the coupler aligned with the first side of the coupler and an umbilical which carries power from a surface of the geological formation to the second side of the coupler. Power is sent from the second side of the coupler to the first side of the coupler, from the first side of the coupler to a first side of the electrical isolation, and from the first side of the electrical isolation to a second side of the electrical isolation via an isolation barrier. The power at the second side of the electrical isolation is provided to the electronics.