Cooling for power distribution systems

In accordance with at least one aspect of this disclosure, a power distribution system having integrated cooling includes a chassis defining an interior cavity, an electronics bus structure housed within the interior cavity, and an electrical contactor operatively connected to the electronics bus structure to receive a voltage therefrom. One or more heat dissipation fins can be included extending away from the chassis and configured to dissipate heat from the electronics bus structure to an ambient environment external to the chassis. In embodiments, the electronics bus structure can be sealed within the interior cavity.