A method of operating a power delivery system that has at least one power cell includes directing air into the power cells to cool them, receiving the air from the cells, directing the air to a cooling system, and recirculating the cooled air to the power cells. Each cell may include an air intake, an air output, a water-cooled heat sink, and optionally a plurality of capacitor connectors and/or a circuit board. The air may be directed through the air intake to the air output so that air passes over the capacitor connectors and/or the circuit board before passing over the heat sink.