When I first read this article, I think several things. Firstly, is it really a good idea to grow vegetables, organic or not, on an old landfill? I would guess: NO! When growing vegetables, above or in the ground, they absorb all the toxins and heavy metals that are readily available in the soil. You can only imagine that the landfill in kibera is not an up-to-date aired and lined landfill; it is probably just a heap of rubbish. In oxygen deprived landfills dioxins and other very toxic compounds are created, and these would immediately be absorbed into the food. It is just a reminder that poor people are treated as second class humans, that do not deserve the same things we do in richer nations. They do, of course, also deserve safe food that will not poison them.

Secondly, using biodigesters to create methane to make gas for cooking and electricity is not futuristic at all. It is a technology that has been successfully used in most countries with a functioning sewage system and wastewater treatment plants, for a long time. Methane is a by-product, and in Stockholm it is used for public transportation buses, cooking gas, and electricity.

I appreciate the digging you did, Leah, to find the articles on the California dairies working to capture and treat methane to produce renewable gas. I wonder whether the U.S. is really behind the times when it comes to exploring alternative energy sources -- but the work that's being done is either not regularly highlighted or is ill-supported by the government and private sector (or perhaps a combination of both). There are interesting examples of methane use in the developing world as well -- I recently returned from a visit to the Rio Muchacho organic farm in Ecuador where they've built a simple biogas plant where fermented manure produces energy for cooking, heating water and lighting. The design was based on a model in Vietnam, and the farm has been using this technique for a number of years, so it's not viewed as a "futuristic" practice though it is still far from standard.

Four Vermont Dairy farmers are capturing methane gas for energy as a way to diversify their farms as the price of milk has slowly declined in recent years. The farmers have received grant money from the federal and state governments, along with the utility company, reports the New York Times.

Utility customers pay a premium price for electricity produced from cow manure, but for many, it's worth it. “Rural customers, in particular, are very excited that something that is considered by some to be a liability, manure, has become, in essence, a resource,” said one utility company representative.

Here's how the process works:

A mechanical scraper sweeps the animals’ waste into a large drain. The waste is then pumped into a huge sealed concrete tank known as a digester, which holds 21 days’ worth of waste and is kept at a temperature of 101 degrees Fahrenheit. Anaerobic bacteria break down the organic matter in the waste, producing a mix of methane and other gases, known as bio-gas. The gas is burned in an engine that runs an electrical generator.

The cow waste produces 250 to 300 kilowatts of electricity daily, enough to power 300 to 350 homes, according to the utility.

As an added bonus, the digester's byproducts are turned into fertilizer and cow bedding.

I did find some interesting (recent) developments in using methane in California. I find it particularly interesting as I grew up in a big farming town in central California, flanked on either side by dairies. Apparently these dairies are now big sources of methane power for California. Most of the articles I have briefly skimmed about the subject come from March and April of this year. It seems that the U.S. is behind the times when it comes to alternative energy sources. Why am I not surprised?

Hi, I have been in oil industry for many years and have reach a point where I have had enough! seen too many countries in Africa fighting poverty...not that we are the guilty ones! I am planning to raise funds to build a village for orphans in Angola. I am supporting an orphanage with about 50 kids...I am looking at building a green village...solar panels, recycling of all waters...agricultural area where they will get introduced to agriculture techniques and where waste waters are reused to irrigate. I am confident I will have the land soon and thereafter will look at all technologies. Can you help me finding out exactly how use waters/organic watsee can be used and methane recovered for kitchen purpose...lighting etc.? Thx for your help. Best Regards
. Xavier