Urban Farming: Could Cows Provide Fuel & Food in Cities?

[wolram]

My idea.
I read somewhere that the gas from three cows could provide the cooking fuel
for a family of five, and you could have fresh milk and cheese, and beef when
the animal is old, i know we don't all have gardens but lots of tower blocks have flat roofs, so that is where they could be kept, the thing is i do not know how much flat roof space an average city has, any ideas ?

 

[BobG]

Bad idea. You must be a 'city folk'. Most 'country folks' know all about cow tipping. A mischievious gang of adolescents going on a cow tipping spree on the roofs of the city's apartment buildings is guaranteed pain for those down on the sidewalk.

 

[Math Is Hard]

Your post reminded me of a book by Marvin Harris, Good to Eat, which studied food taboos within cultures. I remember his ideas from a Cultural Anthropology class I took. He proposed that the religious restrictions on eating cows in India had their roots in practicality.

Here is an interview with him:http://aurora.icaap.org/archive/harris.html

In the pre-Hindu period in India, during Vedic times, cattle were slaughtered and consumed; beef was in fact one of the most important foods offered to the gods and consumed by the participants in pre-Hindu rituals. With the passage of time the Brahmans, who were in ancient times the caste responsible for the slaughter of cattle, became the caste responsible for the protection of cattle against slaughter. Cattle occupied an essential position in Indian agriculture as power animals, and a choice had to be made between raising cattle for plowing purposes and raising them for meat production; the Indian ecosystem and production system couldn’t support both functions. With further intensification of plough agriculture and the ever-increasing density of the Indian population, the sacredness of the cow became an important barrier against development of a meat slaughter industry which would threaten the availability of plough animals to poor peasant farmers. The result is that far from being useless, as many people assume, cattle are India’s tractors. As a byproduct, the cows also produce milk; but their most important function is to produce the tractor, that is, the male plow animal. Another benefit that comes from this prohibition on the slaughter of cattle is that it puts a barrier between the farmer and his cattle when there are droughts or other agricultural crises. It is essential that farmers hold on to their plough animals and not give them up for slaughter.

 

[brewnog]

Wolram, I think one of the main engineering issues to overcome is the collection of the gas. I'm thinking either some kind of permanent suction tube attached to the exhaust port of the bovine production unit with some kind of solid filtration system (which itself could feed a fermentation vessel to increase yield), or gas storage units being fitted to the creatures themselves, allowing them free movement but posing more of an explosion risk in areas with a higher likelihood of attack from burning projectiles.

 

[Evo]

Wolram, I think one of the main engineering issues to overcome is the collection of the gas. I'm thinking either some kind of permanent suction tube attached to the exhaust port of the bovine production unit with some kind of solid filtration system (which itself could feed a fermentation vessel to increase yield), or gas storage units being fitted to the creatures themselves, allowing them free movement but posing more of an explosion risk in areas with a higher likelihood of attack from burning projectiles.

We don't have flat roofs here. I was thinking I could keep them in my basement, but there is probably some law about the amount of space each cow must have. Even though I have an acre of land, the restrictions are two acres for one horse.

MIH, interesting article! Love the patch!

 

[brewnog]

We don't have flat roofs here. I was thinking I could keep them in my basement, but there is probably some law about the amount of space each cow must have.

There's probably some law about sticking vacuum pumps up cows' arses, but this is future energy sources we're talking about here, so let's not let a little chap like PC Plod get in our way.


Besides, if they're in your basement, PC Plod won't ever find them! Now go and raid that cattle shed, and get the vaseline out.

 

[Astronuc]

Goats would work on a roof, especially mountain goats.

Pigs, sheep and cows would not work on a roof.

Watch out for low flying sheep.

And, if only pigs could fly.

 

[jimmie]

A mischievious gang of adolescents going on a cow tipping spree on the roofs of the city's apartment buildings is guaranteed pain for those down on the sidewalk.

That would be ironic; a life-long vegetarian killed by "ground beef".

 

[Danger]

Watch out for low flying sheep.

Well now... there's a new twist on the mile-high club.

And, if only pigs could fly.

I suppose they could be cross-bred with flying squirrels so they could glide to a safe landing if they slip off the roof.

 

[zoobyshoe]

I read somewhere that the gas from three cows could provide the cooking fuel for a family of five...

Not to squelch Brewnog's imagination, but I think this must refer to gas from a methane digester fed with their droppings.

As far as that goes, I have never understood why municipal sewage isn't lead into a big methane digester somewhere for the gas to be harvested for some practical purpose or other.

 

[hypatia]

Thank you zoob, I had a horrid image of cows on roofs with tubes. Its just wasen't right I say.

 

[brewnog]

Seriously though, I reckon it does refer to cows farting as well as the methane produced from their hefty turds.

Researchers have estimated that a single cow can emit 100 to 200 liters of methane per day, not including the methane that continues to be generated as bacteria break down the mounds of manure.

http://sfgate.com/cgi-bin/article.cgi?f=/c/a/2004/05/14/BAGJG6LG3R15.DTL


Lovely stuff! Pipes and cows on roofs may become a reality...

 

[wolram]

Thank you zoob, I had a horrid image of cows on roofs with tubes. Its just wasen't right I say.

Aww come on Hypatia, this is the first step to a bio city, the tubes bit is avoidable with good husbandry.

 

[wolram]

Brewy what the ***** is that avatar about ?

 

[brewnog]

What's the problem with my avatar? It's a building site! We love building sites! I can change it if you want, but I think it's pretty nice.

 

[hypatia]

Will it have a cow friendly roof?

 

[Moonbear]

Seriously though, I reckon it does refer to cows farting as well as the methane produced from their hefty turds.

Don't forget the lethal burps! It has to be far worse than cow farts.

 

[Chronos]

Indeed. I can't help but wonder how difficult it would be to convince the cow that the collection device is both comfortable and stylish. I have this disturbing image of them dragging their butts across the pasture like a cat with worms.

 

[zoobyshoe]

Seriously though, I reckon it does refer to cows farting as well as the methane produced from their hefty turds.
http://sfgate.com/cgi-bin/article.cgi?f=/c/a/2004/05/14/BAGJG6LG3R15.DTL
Lovely stuff! Pipes and cows on roofs may become a reality...

From your link:

"The Straus Farms' covered-lagoon methane generator, powered by methane billowing off a covered pool of decomposing bovine waste, is expected to save the operation between $5,000 and $6,000 per month in energy costs. With those savings, Straus estimates he will pay back his capital investment in two to three years.

But the benefits go beyond the strictly financial. An innovator who converted his family's dairy to organic a decade ago, Straus is a committed environmentalist who has worked for decades to make his operation clean, sustainable and environmentally friendly.

In addition to the energy savings, Straus' new methane digester will eliminate tons of naturally occurring greenhouse gases and strip 80 to 99 percent of organic pollutants from the wastewater generated from his family's 63-year-old dairy farm. Heat from the generator warms thousands of gallons of water that may be used to clean farm facilities and to heat the manure lagoon. And wastewater left over after the methane is extracted, greatly deodorized, is used for fertilizing the farm's fields.

"This is a great project, and I hope it will be replicated many times," Straus said. "

This is the largest scale methane producing operation I've ever heard of and I hope it inspires more of them so that average people see it's viable.

This goes back to Wolram's original post. If we're talking about a situation where you already have cows anyway for dairy and meat purposes, methane digesters are a great solution to the problem of what to do with their waste.

If you don't have cows, though, because you live in a town or city, you could still produce your own methane provided you have somewhere to put the digester. a lot of people don't realize they run on plant matter as well as animal waste. Once you get the right bacteria in there to begin with you can feed it with lawn clippings or any soft vegetation.

As for large scale operations involving cows, I don't really know how they operate but if the cows are kept indoors for all or part of the 24 hours in a day, then I suppose their prodigious flatulence could be collected by running the air from the barns through activated charcoal filters. The methane laden charcoal could then be stored for later use, the gas being released by heating it. To be clever and efficient, this would best be accomplished on sunny days in some sort of solar oven.

At any rate, if you have a methane digester, you don't need cows on the roof. A roof lawn or hydroponic system for growing plants to feed the digester would work.

 

[wolram]

We don't have flat roofs here. I was thinking I could keep them in my basement, but there is probably some law about the amount of space each cow must have. Even though I have an acre of land, the restrictions are two acres for one horse.
MIH, interesting article! Love the patch!

You could keep plenty of pigs on one acre, and they virtualy look after themselfs not like pesky plants that need lots of tlc.

For a cheap methane plant all that is needed is a big inner tube, fill with bio
degradeable stuff add water and squish out all the air, as it starts to expand
you can tap off the gas.

 

[brewnog]

a lot of people don't realize they run on plant matter as well as animal waste.

I bloody well don't run on animal waste!

 

[zoobyshoe]

I bloody well don't run on animal waste!

I bet you bloody well have run on it, and slipped and fallen on your "arse" in the process!

 

[brewnog]

TouchÈ mon petit zooboibasket.

 

[zoobyshoe]

zooboibasket.

I am eyeballing this apellation with a high degree of suspicion.