A methane digester is not for everyone, but only the hardiest of self-reliant souls who are striving to get off the grid.
However, one of these digesters is a great way of using the manure on your property and converting it into something highly useful.
If you have a lot of cows - say about 150 or more, you would have enough manure and enough methane to cut back considerably on your energy costs.
But even if you have the manure from a family cow, you could still convert that manure into enough methane gas for cooking or heating water.
Anytime an organic substance - either from an animal or vegetable source - decomposes, it produces methane gas. Methane gas is a greenhouse gas that is supposed to be far more detrimental on our environment than carbon dioxide. A digester takes that gas and converts it into energy.
Plus, unlike oil, which is a finite resource, methane is constantly being produced on our planet. We'll never run out of methane gas. Plus, once methane gas is produced, the waste substances left over - both solids and liquids - can be used as organic fertilizers.
When matter breaks down and there is no oxygen, then the anaerobic bacteria break down the matter and produce biogas as a waste product.
This happens naturally in swamps, rice fields, soils that are water-logged and the intestines of large animals, but can also be manufactured by storing waste in an airtight container and providing an exit valve for the resulting methane gas.
It could if you had enough manure, preferably cow manure, which is one of the best sources of methane gas. If you have at least 150 cattle or more on your land, it would probably be worth the cost to invest in a large-scale, continuous feed methane digester. With that much manure - and the resulting methane - you could easily generate your own electricity.
Most of us small-scale homesteaders would use a batch-type methane digester. They're relatively easy to assemble - if you know welding. It involves getting two drums: one that is 50 gallons and the other 30 gallons. Cut the top off the 50-gallon drum and the bottom off the 30-gallon drum.
Install an exit valve onto the top of the 30-gallon drum. This is where you will tap off the methane gas. Then fill the 50-gallon drum with manure, shredded newspaper and lots of water. Stir it until it becomes slurry - a liquid with particles of manure and newspaper.
Put the smaller drum on top and hold it down with weights. The created gas will force the top drum to rise. Release this first gas into the air. It is crucial to do this because this first gas is highly flammable. When the top drum rises again, this gas should be usable methane gas.
Methane gas - like any gas - is highly flammable. You will want to research this thoroughly before you try this at home. Here's a good resource to get you started.