Looking at the pasture one has to wonder if this power is suppling some type of super secret underground facility. Possibly a government experiemental place. A zombie safe haven in the event off a fall out. Does it supply power to the field to grow the grass faster providing the cows with an electrically charged food source making them super cows or possible pre-cooked. Realized it's probably just a temporary power setup that was used at one time, how disappointing.
Cache is a small bottle cap, waiting around to be discovered.