Being in construction, and saving EVERYTHING, I uses 100 feet of PEX tubing as a conduit and the 10 gauge wire recycled from a well pump repair and  ran that to the new coop.  Both would have been in the dumpster/recycle pile if I hadn't saved them.  I mounted a new waterproof junction box under the deck on the house, and ran a short section of 8-gauge extension cord (yup, from a jobsite) inside and have that plugged into an existing GFCI outlet in the basement.  Trenched the whole thing underground using my backhoe.  I bought a few junction boxes, outlets, lampholders, covers etc, and used a bunch of short sections of 12/2 (you guessed it....scrounged and saved), and my whole coop electrical system cost me MAYBE $30.  Gotta save where I can, I'm down to working about 25 hrs a week.