Electrical panel structures for a modular building system, such as a modular data center. The electrical panel structures provide a standardized structure for attachment of high voltage power, low voltage power, and/or data lines between rooms or components of the modular building system. The panel structures can include multiple conduits that extend between rooms or other components of a modular building structure. The panel structures can include, for example, conduits having couplers for the attachment of high voltage cables and/or pass-throughs for the passage of low voltage lines and/or data lines.