Cows don't just provide milk

A few years ago (we're talking about 2008!) I was a guest in a Bed & Breakfast near Dobbiaco (Italy). In the morning I took a seat in the breakfast room and I had the pleasure of having a simple chat with the owner. The kind lady, who became aware of my profession, insisted on having her son accompany me to visit the barn of the family farm.

Well ... even if surprisingly simple, I was literally surprised and fascinated by the technology applied to the barn !! I try to describe it with the help of the following scheme:

A puzzling solution

In the center of the barn (1), the drainage channel (2) (the one used for the daily cleaning of the cowsheds) is designed to convey the waste water and sewage into a large underground tank (3) located in the rear part.

The latter is called "digester" and it is nothing more than a large concrete tank, closed at the top, where the waste water and all the waste deriving from the cleaning of the barn (including also the "wet" produced by the activity of the Bed & Breakfast) are "digested" by bacteria, naturally present, with the production of a large amount of "biogas", that is a mixture of carbon dioxide and methane.

Through an underground pipeline (4) the biogas is conveyed into a soft tank (5), that is a large inflatable balloon positioned inside a special technical compartment adjacent to the barn.

The biogas deposit serves to power a "cogenerator" (6). Don't worry ... it's a simple engine that uses biogas as fuel. The movement of this motor is exploited for the production of electricity. Furthermore, the cooling circuit of the engine is water-based: therefore, using this engine, electricity and hot water are produced (we should say "cogenerated"!) at the same time.

So, in summary, through the operation of this "biogas cogenerator", the barn is able to produce electricity to be fed into the electrical network (as in the case of photovoltaic systems!) and also hot water.

For the record, the hot water of the cogenerator cooling circuit is used to heat and maintain the digester temperature (closed red ring, in the scheme, made with simple underground plastic pipes). In this way it is possible to accelerate the digestion process of the sewage, to generate more biogas and to maximize the hours of operation of the cogenerator ... in short, more electricity!!

Personal reflection

Sometimes we look at the agricultural world as if it were ... so to speak .... a world apart, a little distant from the technological world in which we citizens live.

This is absolutely not the case! It's a fascinating world ... it has so much to teach us!!

From today you can look at the cows with a different eye.... because they not only give us milk, but also electricity and hot water!

Please note. Source of some images: web