A server rack with vertically stacked shelves is disclosed. The shelves are used for housing loads (e.g. servers) and power supply units. Thus, both the power supply units and the servers are vertically stacked in the rack. An array of vertical and horizontal busses is secured to the back side of the server rack to electrically couple the servers with the power supply units. The arrangement of the PSUs and the busses provides for uniform current density across the server rack. The devices placed on the shelves are accessible and serviceable from the front of the server rack. The server rack can be placed within or secured to a device, system or a server room in a vertical orientation, a horizontal orientation or at an angle.