How Electricity and Carbon Offsets are Produced from Cow Manure

Hi Deb!

The short answer is yes; most definitely!

When I was working in India I saw many small biogas systems being used on farms. You probably won't be able to create enough energy to run your entire farm, but you could probably run a small generator that was used to do a small job like heating the chicken coupe or running some night time lighting system to ward off intruders. 

Here is a picture of roughly what sized system you would need to build for your farm. This type of biogas digester is called a "fixed dome" system and is cast in concrete. This is a relatively simple system and is also very cheap.

The way that it works is by loading your compostable materials like dung and food scraps into the loading channel like the own shown here. 

As the material moves through the system it is digested by the anaerobic bacteria and the methane (biogas) builds up in the top of the dome. There is usually a simple automatic pressure gauge that allows the gas out through the pipes located on top of the dome. You can see the pipes next to the brick on top of the dome in the picture above. 

You can see what larger systems look like on the Siemens Water Website.

Hope this helps, 

Matt

Deb, you need to take serious safety precautions if you decide to operate a farm-scale generator. Farmers are killed by methane (actually by the absence of oxygen) every year when they look into a methane-generating tank or any area where anaerobic digestion or fermentation is taking place. Here's a typical link to a Washington Post story reporting the tragic, preventable deaths of four people in one incident. You need something like an air-pack or an external source of breathing air to maintain this type of equipment. It will need de-sludging periodically but the waste is high in nitrogen and can reduce reliance on artifical fertilizers if spread back on the land.

Farm-scale generators are encouraged in rural China, where farmers are able to use the gas for cooking. They mix  animal and human wastes together in a concrete container, and the gas produced frees the woman of the house from the time-consuming and difficult labour of collecting firewood for cooking. That's an environmental win-win, reducing methane emissions and pressure on treed areas at the same time. Just be very careful if you try it.

This is a better-late-than-never comment.