There has been some good options so far. Nice picture farm hunter, definitely worth a thousand words. I agree field corn would be the best option, it can endure the weather better than most, especially after frost. Maybe their is a reason you have ruled it out already. I would think you could get a local farmer to put it in, and get him to wait till winter to harvest. That way it would not cost you anything, but it is going to take more than a 15 ft strip, more like 30 to 50 ft. Some of the grasses are another good option. I have had fairly good luck with pearl millet. Last year the price of the seed was .78 cent a pound. It gets fairly tall 3 to 7 ft and grows fast in just about any soil. It would stand for a while after frost. Sunflowers would be my last option, for the same reasons farm hunter mentioned, and they are prone to wind damage.