Build a couple small wind generators. IIRC, it's as simple as some PVC fins, a pole, and a high voltage, low amp electric motor. Use it to charge batteries and run something small like block heaters, gate openers, etc. $200 or so to build a decent setup that gives ROI much quicker than a commercially made wind generator.
Solar has a much better ROI when buying commercially.
If you have a stream or river on your property, you can also build a small hydro generator much like building a wind generator. The power of water is relentless.