manure to methane

Okay now for the real scoop, and I do mean scoop.
The bad news-
Your average well fed dairy cow makes over 100 pounds of manure per day.
The good news-
Your average well fed dairy cow makes over 100 pounds of manure per day

Q. Why is that good news?

A. Through a process called anaerobic digestion manure can produce a gas which is mostly methane, the same thing as "natural gas".

Q. After eating 2 bowls of bean soup I had a lot of anaerobic digestion myself and yes, I did pass gas. Although this seems quite natural why should I consider it good news? None of my co-workers did!

A. Lets get back to the subject which is supposed to be cow manure not your personal indiscretions. As I was saying it is good news that cows make a lot of manure because certain types of bacteria convert the manure to methane through a process known as anaerobic digestion. This bio-methane can do all the same things natural gas does but it is better than natural gas because it is renewable.

Q. How many cows will I need so I can stay warm and stop paying my power bill?

A. It would depend on how much power you use, but 4 to 6 cows can produce enough manure to provide enough methane for the average home. However it is unlikely that your neighborhood zoning will allow you to keep cows in your yard. And even if you live in a cow friendly ‘hood there is the cost of building a collection and storage facility for all the manure. Generally speaking you will need a large tank that must be filled with the right percentage of manure solids and water. Plus you would have to buy and install a generator. Then there are some technicalities involved in keeping the manure warm enough so the bacteria can digest it and produce methane. Now you can see that this anaerobic digestion stuff is not something the average citizen can do for herself. However if you are operating a dairy with 500 or more cows you will have enough manure to produce all the electricity you need for your dairy plus you may be able to sell extra electricity to your electric utility company.

Q. So why aren't all the dairies producing electricity as well as milk? Couldn't we use biogas methane to replace a lot of the oil we buy from the Arabs?

A. Unfortunately in the US very few dairies use anaerobic digestion to produce electricity. Electric utilities in the US often make it difficult for dairies to use the power they generate and will not buy power. Also the initial cost of installing the anaerobic digester and power generation equipment is around 1 million dollars for most dairies and although a digester can pay for itself in about 6 years it can be difficult to raise the money for such an operation. In many European countries anaerobic digestion is used to produce methane and generate electricity from many types of waste, including human sewage and garbage. The US could reduce its dependence on Arab oil, reduce global warming, reduce pollution, and improve the environment by anaerobically digesting waste, all kinds of waste.
But this won’t happen until we (us citizens) insist on changes. We need to become informed, write letters to our elected officials tell them we want our sewage and garbage used to generate electricity. We want dairies, other farmers, food processors, municipal sewage operators and landfills to be able to sell power they generate to the electric utilities. We need to be willing to volunteer to pay a little more for this environmentally friendly alternative energy. We need to say we would rather pay a few cents more for home grown power than spend billions to buy oil from countries that support terrorists.