Wednesday, March 7, 2012

160 Make meat-eaters pay with a Meat Tax - Peter Singer

During World War II, vehicles were modified to run on many different fuels.

Some I've heard of include animal manures, and wood. Do you know of others?

During Mao's time, China recycled its sewage. In early 1987 I saw big pits in the countryside (next to toilets) storing sewage, which was later put on the fields. I even heard that China used to bring Hong Kong's sewage to China by ship.

That's all changed now. Cities on the Yangtze - at least, those uptream of the Three Gorges Dam - now pump sewage into the river. And downstream towns draw drinking water from the river.

(1) Make meat-eaters pay with a Meat Tax - Peter Singer
(2) Vegetarians' meat tax plan just a load of hot air
(3) Argentina: Disappearing Farmers, Disappearing Food
(4) Methane from Sewage turned into Electricity (with Fuel Cells)
(5) Sweden Processing Sewage Into (Methane) Biogas
(6) Bio-Methane from Sewage Sludge to Be Used as Bus Fuel
(7) Norway turns to human waste-powered buses
(8) Running on Pig Manure

(1) Make meat-eaters pay with a Meat Tax - Peter Singer

Make meat-eaters pay: Ethicist proposes radical tax, says they're killing themselves and the planet

By Peter Singer

Sunday, October 25th 2009, 4:00 AM

Taxes can do a lot of good. They pay for schools, parks, police and the military. But that’s not all they can do. High taxes on cigarettes have saved many lives – not only the lives of people who are discouraged from smoking as much as they would if cigarettes were cheap, but also the lives of others who spend less time passively inhaling smoke.

No reasonable person would want to abolish the tax on cigarettes. Unless, perhaps, they were proposing banning cigarettes altogether – as New York City is doing with transfats served by restaurants.

A tax on sodas containing sugar has also been under consideration, by Governor Paterson among others. In view of our obesity epidemic, and the extra burden it places on our health care system – not to mention the problems it causes on a crowded New York subway when your neighbor can’t fit into a single seat – it’s a reasonable proposal.

But in all these moves against tobacco, transfats and sodas, we’ve been ignoring the cow in the room.

That’s right, cow. We don’t eat elephants. But the reasons for a tax on beef and other meats are stronger than those for discouraging consumption of cigarettes, transfats or sugary drinks.

First, eating red meat is likely to kill you. Large studies have shown that the daily consumption of red meat increases the risk that you will die prematurely of heart disease or bowel cancer. This is now beyond serious scientific dispute. When the beef industry tries to deny the evidence, it is just repeating what the tobacco industry did 30 years ago.

Second, we have laws that ban cruelty to animals. Unfortunately in the states in which most animals are raised for meat, the agribusiness lobby is so powerful that it has carved out exemptions to the usual laws against cruelty.

The exemptions allow producers to crowd chickens, pigs and calves in stinking sheds, never letting them go outside in fresh air and sunlight, often confining them so closely that they can’t even stretch their limbs or turn around. Debeaking – cutting through the sensitive beak of a young chick with a hot blade – is standard in the egg industry.

Undercover investigations repeatedly turn up new scandals – downed cows being dragged to slaughter, workers hitting pigs with steel pipes or playing football with live chickens. We may not be able to improve the laws in those farming states, but taxes on meat would discourage people from supporting these cruel practices.

Third, industrial meat production wastes food – we feed the animals vast quantities of grains and soybeans, and they burn up most of the nutritional value of these crops just living and breathing and developing bones and other unpalatable body parts. We get back only a fraction of the food value we put into them.

That puts unnecessary pressure on our croplands and causes food prices to rise all over the world. Converting corn to biofuel has been criticized because it raises food prices for the world’s poor, but seven times as much grain gets fed to animals as is made into biofuel.

Fourth, agricultural runoff — much of it from livestock production, or from the fertilizers used to grow the grain fed to the livestock — is the biggest single source of pollution of the nation’s rivers and streams, according to the EPA. A meat tax would be an important step towards cleaner rivers. By reducing the amount of nitrogen that runs off fields in the Midwest into the Mississippi, it would also stop the vast ?dead zone? that forms in the Gulf of Mexico each year.

The clincher is that taxing meat would be a highly effective way of reducing our greenhouse gas emissions and avoiding catastrophic climate change.

Here’s just how bad eating meat is for global warming.

Many people think that buying locally produced food is a good way to reduce their carbon footprint. But the average American would do more for the planet by going vegetarian just one day per week than by switching to a totally local diet.

In 2006 the United Nations Food and Agriculture Organization surprised many people when it produced a report showing that livestock are responsible for more emissions than all forms of transportation combined. It’s now clear that that report seriously underestimated the contribution that livestock — especially ruminant animals like cattle and sheep – are making to global warming.

As a more recent report by the Intergovernmental Panel on Climate Change has shown, over the critical next 20 years, the methane these animals produce will be almost three times as potent in warming the planet as the FAO report assumed.

Meat-eaters impose costs on others, and the more meat they eat, the greater the costs.

They push up our health insurance premiums, increase Medicare and Medicaid costs for taxpayers, pollute our rivers, threaten the survival of fishing communities in the Gulf of Mexico, push up food prices for the world’s poor, and accelerate climate change.

Red meat is the worst for global warming, but a tax on red meat alone would merely push meat-eaters to chicken, and British animal welfare expert Professor John Webster has described the intensive chicken industry as “the single most severe, systematic example of man’s inhumanity to another sentient animal.?

So let’s start with a 50% tax on the retail value of all meat, and see what difference that makes to present consumption habits. If it is not enough to bring about the change we need, then, like cigarette taxes, it will need to go higher.

Singer is professor of bioethics at Princeton University, the author of “Animal Liberation” and the author, with Jim Masion, of “The Ethics of What We Eat.”

(2) Vegetarians' meat tax plan just a load of hot air

Date: November 01 2009

Chris Berg

This week British economist Lord Stern called for the world to get off beef and on to broccoli: go vegetarian for the planet. Methane - burped, belched and otherwise released by cows in impressive amounts - is around 20 times more potent a greenhouse gas than carbon dioxide.

So the author of the influential 2006 Stern Review into global warming told Britain's Times newspaper that the climate change meeting in Copenhagen would only be a success if it led to skyrocketing meat prices. Otherwise, Stern predicts, climate change will turn southern Europe into a desert and there will be ''severe global conflict''.

Stern isn't alone. Also this week, Peter Singer called for a 50 per cent tax on all meat. According to the Australian vegetarian philosopher, cows are pretty much like cigarettes: they're bad for you and smelly. They should be taxed accordingly.

It may come as a surprise, but there are flaws in this plan. We could all go vegetarian tomorrow if we tried - good news for the vitamin supplements industry. But a world without meat would be a much sadder world. And at best we'd be making a marginal change to global emissions.

According to NASA's Goddard Institute for Space Studies, 85 per cent of methane from cattle is produced by cows in the developing world, because they have poorer diets, which produces more methane. And many of those cows aren't just hanging around in paddocks waiting to become tasty beef - they're work cows. India's 283 million cows aren't being eaten.

One environmentalist gripe is that cattle raised for human consumption themselves consume vast amounts of food that could go instead to humans. But grain-feeding produces less methane than feeding on wild grass. Purpose-grown feed is, at least in some respects, more environmentally friendly.

So: cow farts are a surprisingly complex issue.

It's easy for Stern and Singer to urge the developed world to change its ways. But it would be much harder - and would get them invited to far fewer cocktail parties - if they decided a good use of their time was haranguing poor Indians into giving up their livestock. Stern and Singer are proposing little more than a green indulgence for the wealthy.

Anyway, practical problems aside, there's something obscene about the idea that governments should deliberately make basic staples of life more expensive.

After all, Stern and Singer's meat tax is hardly the only tax on food being proposed. Public health activists are adamant that the only way to get people to shed their ugly kilos is by making sweets more expensive.

Taxes on food have been among the most punitive in history. Dissatisfaction with taxes on salt was one of the causes of the French Revolution. Gandhi marched against the British salt tax.

We forget just how far we've come. A few centuries ago, getting hold of affordable and edible meat was like playing roulette - if the roulette wheel was made of parasites and salmonella.

Early cookbooks spent almost as much time teaching household chefs how to identify spoiled meat as they did describing recipes. The Compleat Housewife, published in 1727, told readers to prod carefully at beef in a marketplace. If the meat sprang back, it was fresh.

Admittedly, there is a positive spin you could put on the proposals to tax our food consumption: finally, the human race is so rich, so comfortable, that we can start making it a bit harder to get our basic needs. But food taxes will disproportionately affect the poor. If meat was as expensive as environmentalists would like, the rich wouldn't significantly reduce their wagyu steak intake, but families on a tight budget would certainly eat less three-star mince.

And (need it be said?) hunger caused by inadequate or low-quality food supplies is still a major problem in the developing world. Just this year, in the Central African Republic, malnutrition caused by limited meat has created a humanitarian disaster.

These contemporary crises should remind us that humanity's greatest struggle has been against malnutrition and starvation. Not for nothing did the Nobel Prize winner Robert Fogel title his groundbreaking study of recent global history The Escape from Hunger and Premature Death.

Since 1950, the global population has increased more than 150 per cent. But, in real terms, the price of food has sharply declined in that period. Basic commodities such as grain and vegetables are 75 per cent cheaper than they were 60 years ago. And it's the potent combination of rapidly expanding economic growth and technological change that did it.

But we shouldn't forget how hard it was to get where we are today. Cheap food is our inheritance as human beings.

Chris Berg is a research fellow with the Institute of Public Affairs and editor of the IPA Review.

(3) Argentina: Disappearing Farmers, Disappearing Food

By Marie Trigona

Toward Freedom

Thursday, Oct 29, 2009

Worldwide, industrial mono-culture farming has displaced traditional food production and farmers, wreaking havoc on food prices and food sovereignty. This is particularly true for the global south, where land has been concentrated for crops destined for biodiesel and animal feed. In response, peasants and small farmers organized actions in more than 53 countries on October 15 for International Food Day as an initiative of Via Campesina, one of the largest independent social movement organizations, representing nearly 150 million people globally.

The National Indigenous Campesino Movement of Argentina joined the protests taking place on around the world by organizing a march in Buenos Aires for International Food Day. Argentina has often been described as South America’s bread basket because it once produced grain and beef for much of the region. But with the transgenetic soy boom the nation has shifted to a mono culture production for export, displacing traditional food production and farmers.

Hundreds of campesinos marked the day with protests against this agricultural model outside of Argentina’s Department of Agriculture. “For the government, the countryside [is made up of] the landholding organizations and the agro-businesses, we practically don’t exist,” says Javier from the campesino movement in Cordoba, an organization that includes more than 1,500 families who have depended on traditional agriculture for generations.  “We are also part of the countryside. We are the ones who live on the land and protect the land. We want to continue to live on our land, for future generations.”

Evicted Farmers

According to Argentina’s 2008 agricultural census, more than 60,000 farms shut down between 2002 and 2008, while the average size of farms increased from 421 to 538 hectares. The shift to soy has replaced cultivation of many grains and vegetables and even the country’s beef production. Researcher at the nation’s social research institute CONICET, Tamara Peremulter outlines the affects of monoculture soy on food production. “Soy historically hasn’t been grown in Argentina. Soy was brought in during the 1960’s during the Green Revolution. Transgenetic soy has been brought to lands where before cultivation wouldn’t have been possible. The low production cost of soy helped this process. Soy has replaced other crops, invading areas that were historically for cattle grazing and dairy production. Soy has also invaded indigenous and traditional farming communities. This model also implies deforestation and loss of biodiversity”

Land access and disputes over land titles has become one of the central issues for traditional farmers being replaced by machinery and high tech mono-culture farms. The National Indigenous Campesino Movement of Argentina (MNCI) reports that 82 percent of farmers live off of 13 percent of the nation’s land used for agriculture, while 4 percent of large land holders or “growing pools” financial investors in the agro industry own more than 65 percent. The disparities in land titles have lead to violent evictions.

On October 12, 2009 a day on which indigenous communities commemorate the genocide of their people following Christopher Columbus’s arrival in 1492, an indigenous farmer, Javier Chacoba was murdered during a protest against the forced eviction of indigenous people off of lands. The 68-old farmer died of a gun shot wound to the abdomen by Dario Amín, a landowner. Members of the Chuschagasta community had been camping along a provincial highway bordering the lands to demand land recognition for the Chuschagasta when Amín and two ex-police officers showed up at the protest. “On the day commemorating 519 years of genocide in Latin America, we suffered the loss of our brother (Javeri Chacobar) for simply standing up for his rights, defending his dignity and land that belongs to him,” said Margarita Mamaní, member of the Chuschagasta community.

“They have been evicting farmers and members of the indigenous community from lands. People have been killed in the evictions,” says Ricardo Ortiz is an indigenous representative from The Campesino Movement of Santiago del Estero (MOCASE).  More than 9,000 families make up MOCASE, a grassroots movement of traditional farmers and indigenous groups. “Now they killed a farmer in Tucuman, a brother. He was in a march to demand their rights and the man who bought the lands took out a gun and shot the man and injured four more. The government has been blind, deaf and mute; this is why we are worried.”

Police Repression

In 2008 alone more than 35 campesinos were arrested and arrest warrants issued for 95 more, in Mendoza, Formosa and Santiago del Estero, in communities rejecting the agro-industrial model. Santiago del Estero is a province once rich in forest land and untouched by soy. This changed as the boom in soy prices has made these remote areas now profitable for soy growers.

This is a “witch hunt,” as the MNCI has described the situation for campesinos resisting land evictions, and defending traditional cultures.  Local police enforce eviction orders and meet any resistance with police force, clubs and many times bullets. “Campesinos resisting are suffering a violent political persecution. We demand that detained farmers are released, that officials, judges and police that violate human rights be investigated and that evictions are stopped,” declared the MNCI.

Agro Industry Creates Joblessness

The shift to mono-culture crops and land concentration has stretched into cultivations traditionally employing small farmers such as vineyards. Argentina’s wine industry has boomed in recent years, with the total value of Argentine wine in the US increasing from 75 million to 146 million dollars between 2006 and 2008. Mendoza is Argentina’s largest wine producing region, with a micro climate perfect for the Malbec grape. Access to water is a major issue for rural and indigenous communities there.

Marcelo Quieroga from the Union of Rural Workers (UST) says that much of the vineyards in Mendoza have been monopolized by French and Swiss investors, who buy land and mechanize wine production. “They are using machinery to replace workers. By producing high quality wines for export the wineries have essentially monopolized the production. Who suffers is the rural worker who can’t find work, and ends up living in a shanty town due to rural unemployment.”

Rural displacement results in poverty and joblessness; the poorest provinces in Argentina have ironically hosted a boom in soy industry, with soy fields replacing forests and even cattle grazing land. The MNCI has reported that the soy model creates only one job post for every 500 hectares cultivated. Meanwhile, traditional agriculture provides 35 job posts for every 100 hectares cultivated, while also guaranteeing food diversity, production or local markets and sustainable use of resources such as land and water.

Food Sovereignty

Industrialization and the globalization of Argentina’s food system has led to spikes in food prices, and increasing rural poverty. This has become a global trend. “A billion people are without food because industrial monocultures robbed them of their livelihoods in agriculture and their food entitlements,” writes Vandana Shiva in the Nation Magazine.

Via Campesina does have an alternative to the agro industry, pushing for governments to promote local, traditional farming which provides communities with real food. “It’s time for all civil society to recognize the gravity of this situation, global capital should not control our food, nor make decisions behind closed doors. The future of our food, the protection of our resources and especially our seeds, are the right of the people,” said Dena Hoff, coordinator of Via Campesina North America.

Food sovereignty as defined by Via Campesina is the peoples’ right to define their agricultural and food policy, and the right of farmers and peasants to produce food. Worldwide communities are seeking an alternative to a model controlled by Cargill, Monsanto, General Foods, Nestle and Kraft foods. Starved by industrialization and concentration, citizens are now hungry for traditional production methods and diversity in the food system.

(4) Methane from Sewage turned into Electricity (with Fuel Cells)

Poop power? Sewage turned into electricity

Fuel cells and waste sludge mix to power treatment plant

By Miguel Llanos

updated 12:31 p.m. ET July 19, 2004

RENTON, Wash. - It's not as neat as spinning straw into gold, but what Greg Bush gets to do in the world of sewage treatment is pretty magical: making electricity from what's flushed down the sewer. And he does it using fuel cells, technology that's cleaner and more efficient than traditional power generation.

It's also still a lot more expensive, but that's the point of the $22 million project -- to build a power plant that can then be replicated at lower cost at sewage treatment plants across the United States, and there are hundreds of them. The power would be used inside the treatment plants and any excess could be sold to the power grid.

Day in and day out, some 700,000 people send 86 million gallons of sewage, mostly toilet and kitchen waste, to the King County treatment plant in Renton, a Seattle suburb.

Little do they know that 30 million of those gallons are producing enough methane gas to run the 1 megawatt, fuel-cell power plant that was built here this year. The system can power 1,000 homes, but in this case all the electricity is going to help run the treatment plant, which needs about 7.5 MW per hour a day on average.

How it works

The largest project of its type in the world, the process goes like this: Biodegradable solid waste is sent to large tanks, called digesters, that provide a home for three to four weeks. There bacteria eat away at the waste, releasing methane gas and further reducing the amount of solid waste.

"We maintain a nice little environment for bacteria: warm and wet," says Bush, program manager for the project, which is funded by the U.S. Environmental Protection Agency, FuelCell Energy and King County.

Most treatment plants flare off the methane, and a few burn it to get electricity for their sites. But the Renton plant captures the gas and sends it to a fuel cell system, where the methane is broken down into hydrogen and carbon dioxide. The carbon dioxide is recirculated to produce carbonate.  The carbonate then combines with the hydrogen to produce electricity, water, carbon dioxide and heat.

Fuel cells operate like a battery, and methane or any other fuel containing hydrogen can be used to power the process. A key advantage to fuel cells is that they are much more efficient at generating electricity than the combustion process found in today's cars and power plants.

Long, hard road it's been
King County had been looking to start the project six years ago, and was set to go when the first fuel cell company it partnered with went bankrupt.

FuelCell Energy, a company based in Danbury, Conn., eventually stepped in, and has a team of four helping prep the project. Eventually, the system should be stable enough to monitor it remotely from Danbury.

The fuel cell technology used is different than that being developed for cars. Even though no combustion is involved, FuelCell Energy's stacks reach temperatures up to 1,200 degrees Fahrenheit.

"You wouldn't want to drive around with 1,200 degrees in your car," says Dan Beachy, project leader for FuelCell Energy.

Will it make economic sense?

Even with all the effort, there's no guarantee that the pilot project will make sense economically. For one, the fuel cell stacks need to be replaced every four years or so, and that's one of the pricier parts of the system.

The fuel cell industry does expect costs to come down as production ramps up.

Steve Eschbach, FuelCell Energy's communications director, says typically with each new power plant delivered "we're able to lower the cost by 25-35 percent" due to lessons learned from previous plants. ...

A bonus feature for waste treatment plants is that instead of burning off the methane, another gas tied to global warming, it can be used to create electricity.

Not built for spikes
A big drawback to fuel cells, however, is that they can't ramp up quickly for sudden spikes in electricity demand. At the treatment plant, that typically happens during a big storm, when waste water flows faster into the plant and more electricity is needed to pump the extra water out to the ocean once it's treated.

As a result, King County is planning a more traditional power plant, one that burns methane and can be ramped up quickly. "You need to think dual fuel," says Eddie Tate, construction manager for both projects.

The fuel cell project will also be scrutinized by an outside committee, whose members include Gordon Bloomquist, a program director at the Washington State University Energy Program. He says he'll be watching to see if methane proves compatible with fuel cells and just how reliable the system is.

As for the economics of fuel cells, he says, "it's not clear how the cost effectiveness is going to work out, but this project is a major step forward in terms of determining that."

For King County, the numbers work because it put up just $2 million of the $22 million project, and it is allowed to keep the fuel cell system after the two-year project. "That's the plan if everything goes well," says Bush. "It fits in with our overall goal of being as energy independent as possible."

(5) Sweden Processing Sewage Into (Methane) Biogas

May 30, 2008    (Click to Rate!)  Loading ...

Life & World

Sweden is currently leading the charge in processing sewage, using bacteria, into methane gas that is captured from sewage processing facilities and delivered into the natural-gas grid to filling stations that biogas-enabled cars can use to fill. While other European countries are also on the biogas bandwagon, there are huge commercial backers to the ethanol idea, even though it has been proven to be an inefficient fuel both technically and push unnecessary pressures onto the world’s food supply and cost of food.

WhiIt appeared that Volvo (owned by Ford) was the leader in Sweden’s biogas market, they stopped producing the vehicles after not selling enough. Mercedes and Volkswagen are stepping this year to release new biogas models for the European market.

Original biogas car models weren’t all roses though, with complaints of poor performance in both power and miles-driven-per-tank, the revived uptake in biogas will hopefully see revised models that continue to make use of the processed sewage-based gas.

One of the most motivating factors behind processing sewage to make biogas is how completely the process breaks down otherwise useless material into usable components:

    Chemically, biogas is the same as natural gas from fossil fuels, but its manufacture relies on a process where bacteria feed on fecal waste for about three weeks in an oxygen-free chamber. The result is two-thirds methane and one-third carbon dioxide, as well as a nutrient-rich residue that can be used as soil or construction material.

Let’s hope this trend continues and investors bring the effort state-side at some point.

(6) Bio-Methane from Sewage Sludge to Be Used as Bus Fuel

Wednesday, May 17, 2006 Posted: 11:25 AM JST

Kobe City in western Japan has decided during fiscal 2006 to prepare for the practical use of bio-methane gas as a fuel for natural gas vehicles. The gas is produced by purifying the gases generated from sewage sludge. This is the first attempt of its kind in Japan.

The new bio-gas was developed jointly by the city and Kobelco Eco-Solutions Co., a subsidiary of Kobe Steel. They started verification tests in October 2004 using a purification system installed at the Higashinada Sewage Treatment Plant. They successfully produced methane gas at 98 percent purity, the same level as city gas, by applying high pressure to the gas generated by microorganisms decomposing sewage sledge, and dissolving impurities such as CO2 and hydrogen sulfide, which make up 40 percent of the gas, in water. In 2005, they began to use this gas to run natural-gas-fueled city buses on a trial basis.

Bio-methane gas is a biomass energy source that does not result in any net CO2 increases in the atmosphere and discharges few atmospheric pollutants, such as nitrogen oxides or sulfur oxides, when burnt. The newly developed gas is seen as a promising clean energy source as it is 30 to 40 percent less expensive than gasoline. The gas is known as "Kobe Biogas", which was selected from among names proposed by the public.

A new purification plant is being built at the Higashinada Plant, with operations planned to begin in spring 2008. It will supply enough bio-methane gas for 40 city buses, each running 50 kilometers per day, or 700 passenger cars, each running 30 kilometers per day.

First published in May 2006 by Japan for Sustainability (JFS). Many thanks to JFS for their kind permission to reprint the article at

(7) Norway turns to human waste-powered buses
Monday, 23 March 2009
Agence France-Presse

Stockholm, in Sweden, already has 70 buses running on biofuel. Soon biofuel will power 350-400 buses in Oslo.

OSLO, NORWAY: Can the key to "clean" energy be found down in the sewer? That's the idea in Oslo, where city officials soon plan to introduce buses that run on biofuels extracted from human waste.

As of 2010, the new buses are due to start plying the streets of the Norwegian capital.

"It's a win-win situation: It's carbon neutral, it hardly pollutes the environment, it's less noisy and its endlessly renewable," says Ole Jakob Johansen, one of the people in charge of the project at Oslo city hall.

The biofuel, which is methane generated by fermenting sludge, will come from the Bekkelaget sewage treatment plant which handles waste from 250,000 city dwellers.

"By going to the bathroom, a person produces the equivalent of eight litres (2.1 gallons) of diesel per year. That may not seem like a lot, but multiplied by 250,000 people, that is enough to operate 80 buses for 100,000 kilometres (62,000 miles) each," Johansen says.

Compared to diesel, biomethane is a giant green step forward.

In addition to being carbon neutral, it emits 78 per cent less nitrogen oxide and 98 per cent fewer fine particles -- two causes of respiratory illnesses -- and is 92 per cent less noisy.

Even the price is advantageous, says Johansen. All included, the cost of producing biofuel equivalent to one litre of diesel comes to 0.72 euros (98 cents), while diesel at the pump in Norway currently costs more than 1.0 euro.

"The fuel is less expensive but the cost of the new buses and their maintenance is higher. In total, it's about 15 percent more expensive," notes Anne-Merete Andersen of Ruter, the operator of Oslo's public transport system.

Contrary to first generation bio-ethanol, made from grains and plants, biomethane has the added advantage of not impacting food supplies, nor does it require fertilisation or deplete precious water resources. ...

(8) Running on Pig Manure

Pig manure

The first private effort to produce bio-gas in a controlled way, and in quantity, was by a South African pig farmer (L. John Fry, R.A.F. Ret'd). He was driven to it by desperation: pigs produce a river of excreta (fifteen times as much as humans of the same weight); it is notoriously smelly, driving neighbours past endurance and leading to visits by the police; finally, flies love the nourishing stuff and breed in it.

As a way out, Mr Fry built the first "continuous-feed displacement digester" -- a closed concrete tank, fifty feet long, eleven feet wide and five feet deep. A few sealed hatches were left for access points, and a pipe led to a huge gas storage tank.

The digester was given an initial fill. Every day after that, raw manure from 500 pigs was mixed with water, poured into a loading pit, and pumped into the digester. The glass-tiled loading pit was hosed clean in order to stop fly breeding. Each daily load of manure progressed through the digester, pushed one stage further every 24 hours by the injection of fresh material at the input end. On average, the waste was in the digester about 30 days.

By the time it arrived at the far end of the tank, the sludge was practically odourless, entirely free of harmful bacteria, and much richer in nitrogen than manure composted in an open-air heap. The process would have been worth it just to get rid of the flies and to make peace with the neighbours. But there was also an energy bonanza: 3000 cubic feet a day of bio-gas, continuously, month after month. Part of the gas was used for heating and cooking; the rest powered a diesel generator that supplied electricity to the whole farm.

What works in South Africa (and now in lots of other places) will work on the Isle of Man. Even a dozen pigs can supply a small but practical digester. (The rule of thumb is that 46 pigs equals one gallon of petrol per day. More precisely: the daily excreta from 46 pigs will yield methane with an energy content equal to one gallon of petrol.) So the 4000 pigs on the Isle of Man add up to a petrol output of 87 gallons per day -- not much for the Island as a whole, but quite a lot for the pig farmers.

Other wastes
For cattle, the conversion figure is 5.5 cows per gallon of petrol. (Which assumes that all the manure can be collected.) If you want to use chickens, you'll need 810 of them. The figures are rough but they give some idea of the scope for different farms.

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