The panel is inside. I am drilling a hole to the outside about a foot under the panel. I will mount an all weather box outside and run a short piece of conduit through the wall and straight up in to the box. When I built the garage, I sheet rocked the entire garage except about 32'' of the wall where the panel is. I just remove the front cover on the panel and then the upper and lower pieces of OSB, remove the insulation, and I can run the wire right out of the bottom of the box to the outside and right into the box. I am using a piece of 10-2 NM and it will be in conduit. When I upgraded my compressor, I just pulled the OSB off and ran the new wire up thru the attic and down in to the box where the compressor plugs in. Very little sheet rock repair where the outlet is.