I have been thinking a lot about your last statement. An anaerobic septic system would generate natural gas for you. Many less developed parts of the world us

I have been thinking a lot about your last statement. An anaerobic septic system would generate natural gas for you. Many less developed parts of the world use such systems to generate cooking and heating fuel. But, if you have modern appliances designed for clean natural gas you will also need a small scale gas cleaning system. There are no off the shelf small scale gas cleaning systems so you have to make your own. Then there is the issue that anaerobic septics a illegal in most areas since they stink when vented to atmosphere.