Electricity from Cow Manure

Sort of. If you can get enough of it (and keep the costs of the equipment and its maintenance down) then yes, but the cow-dung makes for great fertilizer which makes the grass grow better, so its really a trade-off.

Have a look on the internet, there are probably a few small-scale DIY designs that have been tried. In the end, you really will need a very large farm with LOTS of cows to produce usable amounts of regular power. If you only have access to 10 or even 100 cows, then you would most likely be wasting your time.

Try looking at solar hot water heating (that's suns rays heating water directly), it's inexpensive, simple and provides VERY good value for money (far better than cow-dung to electricity).

It is not trade off. The biogas plants have two outputs... one is biogas, which you can burn, generate electricity and other is the fertilizer, which you can feed to plants/grass.

The fertilizer is a free byproduct, but to convert the gas to electricity requires equipment that also needs maintenance (hence not free). The trade off comes when you perform a cost vs benefit analysis and find that unless you have a lot of cows you are expending a lot of time for very little gain.

I did a study of biodigestion a few years back to assess the feasibility of this.

IIRC, for a correctly set up and operated biodigester a good rule of thumb was that for a given volume of digester you will get up to the volume of that digester in gas produced. This gas will be a mix of methane and CO2, it may vary from 40% methane up.

We were looking at using milking shed effluent as the feedstock. A 25,000 litre digester tank should generate enough gas to run a generator set which would produce about 20KWh per day, give or take a bit.

Harold Bate holds pressure tank of home-made methane.

see: http://journeytoforever.org/biofuel_library/methane_bate.html

This has been done before with farm waste digesters which create reasonable quality methane to power cars and other equipment. But like others say, the economics are fuzzy. It sounds like more of a personal challenge to achieve a degree of self-sufficiency. I'd be interested myself to do this if I had a farm and the spare time. I work in the natural gas engine field so I have thought about this many times before.

The engine / generator certainly could be sourced and the waste heat allows you to have a co-generation system. Used spark-ignited engines (low pressure gas feed) are best for keeping capital cost low but you must have hardened valve seats / valves for long term durability.

Hi....as i see you are from India. Bio gas etc is very common here in the villages. The government provides help in these cases. You just gotta approach the branch of the Dept of Renewable Energy Sources in your state. They will not only provide you the designs & engineering for a suitable plant, but will help in installing, obtaining a loan and provide you a subsidy on top of it. It's the same for solar water heaters, solar cells.

What more can a eager enterprising person ask for?

There is a video connected with this advert on Youtube someplace

http://www.redferret.net/?p=10222

Absolutely so.

1st. Cow dung to Methane, which burns at +1590 Celsius.

2nd. Residue is fed to South African night crawler worms, excreting world best fertiliser.

3rd. South African night crawlers have very high oil content and readily burn when dried.

Cheers

Peter

Dear Friend

While generating gas from cow dung is not a very complicated process. Getting electricity from this methane isnt all that straight forward. The gas needs to be cleaned of acidic impurities and tar, for the engine. Or else it gets damaged soon. In India, Cummins makes engines suitable for producer gas and so using same for biogas may not be very different. Biogas has much higher percentage of methane than producer gas.

Thanks and regards

Ashok Toshniwal, Bangalore, India

Google "cow power plant" ;

http://www.dailypost.co.uk/farming-north-wales/farming-news/2008/01/10/my-cow-power-plant-should-be-dung-deal-55578-20332001/

http://www.worldwatch.org/node/5599

http://www.riverdeep.net/current/2002/03/032502t_cowpower.jhtml

etc etc..........

kal,

In India it is called Gobar Gas Plant, Khadi village Udyog provides know how and subsidy for installing such plants. Now you have to learn how to make electricity from Gobar Gas.If you can not feed directly to engine then I suggest you can install steam generate and run steam turbine connected to a alternator.Of course there will be loss of energy but it can be one of the solution.

Why not get it at the source, there have been experiments on getting methane gas directly from the cow's stomachs. I know of one done in Holland many years ago where they put an adaptor on it's side connected to the cows stomachs. The below link shows you how they "harvest" the gas. Unfortunately it is in dutch but with babel fish or the like you should get some sense out of it.

http://muziekmuseum.skynetblogs.be/post/6045183/wetenschap-pakt-het-boeren-en-winden-aan

Hmm I wonder how much surgery of this type on a cow cost? Seems like it is awful expensive for a Dairy. Though i would guess vets would love the new business line. Imagine getting the contract to serve two or three Dairies, that would be like 20,000 cattle. The installation and long term expensive maintenance would make the vet a very wealthy guy (of course cheese would get more expensive). What is the morbidity rate? Dairies regularly lose a couple of cows a month as it is. If you add in the cost for losses of cattle with surgical improvements plus the added morbidity, this makes it more expensive. I wonder how PETA would respond to something like this?

Yes, it is feasible. I doubt it is economical.

Very feasible, very economical, provided you get the manure from a dairy farm because the manure is easier to collect. I'll get back with more specific info shortly.

Cow Dung! Bah Humbug! Check out the DOE Joint Genome Institute's work with Methane producing Termites and the Eucalyptus.

www.jgi.doe.gov

Surprising!, You are from India and still do not know that this can be done and is well in practice in rural India. Just visit villages around, somewhere, you will find what you want.

IF I have 10000 cows and buffelows are available,than it is economically feasible to construct a bio-gas plant and what is the approx. bio-gas produced per day and what is the quantity of electricity (KWh).what is the maure produce after bio-gas produced.

Kal,

I assumed you have cowshed with many cows or buffallows otherwise why you will ask such question.

here in Mexico, in one particular dairy complex, 25000 cows produce roughly 800 metric tonnes of manure.

The TVA has a methane producer that takes a capped landfill and generates enough methane to help provide 'green energy', or so their publicity pablum says.

Is it economical? They suggest it is. Since the TVA is a semi-public company you might request some detail from them on it.

(TVA, Tennessee Valley Administration, runs generators from coal, nuclear, hydroelectric, wind, and a little methane in the area of the Tennessee River Valley and surrounding areas. They are now 75 years old, and got started around the 'great depression' era.

www.tva.com for more information. I am an indirect customer of theirs, no other affiliation.)

Talking with our Caterpillar rep. i found that our most populous county is using bio-gas wells in a landfill to power gensets. He said of the large desiplacement engines they can readily be configurd as diesel or spark ignition for such apps.

Many dairies in my state use methane scavenge systems running gensets too. Not new technology. Too often overlooked.

FWIW i've made an experimental size anearobic digester. here:

http://cr4.globalspec.com/thread/30755/Biogas-Power-Generators

What I want to know is how can you make simple systems for septic tanks, you got to figure plenty of gas in those, anyone got some good info/links?

i'll probably get a gig for off-topic but a typical septic system is dependent on operating at 1 atmosphere. Even slightly larger pressures i.e. 3-4" water collumn, typical waste traps won't work properly. Ask somebody that has had a waste stack plugged. OTOH, if you could seperate the soapy grey water from the sewage in a purpose built system, there's no reason why it wouldn't work.

Ya , I agreed with you, thats why Cow dung are a better source compare to human waste, because we consume too much of chemicals and the waste pipe system at our homes links all other soapy water into the septic tanks, this will kill most of the bacterials and effect the digestion result.

For more info please refer to the Results reported from "Haubenschild Farms Anaerobic Digester" , it can be downloaded from http://ww.mnproject.org

Enjoy reading........!

Getting back to the question asked:

You said you have a milking shed and cows.

A couple of fellows have tried differing approaches in the far northern US. Hit the web.

Best result I have seen was a cogenerating facility - the digester tank which takes slurry in produces methane, but also massive waste heat. The tank was lined with tubing to allow heat capture. The methane (well established and discussed here) was piped off for engines as well as heaters for the shed. The hot water used for the farmers home heat.

The output from the biodigester was used as fertilizer, and I think some bagged for commercial sale.

All in all, well worth tackling.

i think it is.

that is if you have a cow farm.

^^