The Science and Infrastructure Behind it
While biogas emissions are plentiful, harvesting it poses a bit of a challenge. For example, the methane produced by cows could power whole countries, yet it escapes into the atmosphere as there is no viable way to harvest it from cows out in the fields. Since it isn't possible to take the biogas plant to the cows, we need to take what the cows produce that generates the methane, their dung, to the bio-gas generator. Since the cost of transporting the feedstock over distances can add up, most existing biogas plants are built in remote agricultural areas near large herds of cattle.
This is a good thing so far as it keeps the unavoidable noxious odor of the process away from the population, but it does pose the challenge of getting the biogas to consumers. At the biogas plant, the dung is concentrated, and mixed with water and other materials that decompose in a similar way, creating a slurry. The slurry is then left to ferment in a digestion chamber. The gas can then be easily collected through a pipe at the top of the domed digestion chamber.
Biogas plants require very little energy to produce the unrefined biogas. It is therefore a very cheap fuel to produce. Technology is only part of the equation of getting biogas production up and running; the greatest idea in the world will never get off the ground without a little seed money. Fortunately for alternative energy producers, many countries have generous subsidies in place for entrepreneurs interested in cashing in on alternative energy.