Biogas: Alternative Energy at Work  

While the cost of carbon-based fuel is rising, people in rural areas across the world are experiencing financial hardships due to the price and inaccesibility of energy. People in rural Costa Rica are no exception. Before implementing the biogas project (what is biogas?), the majority of the people in Santa Fe de Guatuso purchased gas to power its gas ranges. As a result of the town's remote location, the price of a tank of gas had cost over $15 USD. Although this is a cost that many people in the developed world could afford, a family in Santa Fe that used more than one tank per month could not likely pay for the fuel to cook its food. Consequently, many families were forced to supplement their gas with firewood. Although this fuel source had no perceived monetary cost to the family, the practice of cutting trees for firewood was a long-term liability for the region of Guatuso as a whole. Such a practice was also harmful in the short-term, as the firewood was burned in the kitchen and often ignited with plastics and rubbers, which when burned give off carcinogenic dioxins. As a result, the people in Santa Fe were torn between financial, environmental, and health concerns.

While faced with this dilemma, the Santa Fe Women's Group decided to seize an opportunity that conquered this threat to their financial, environmental, and physical well-being. The group chose to use the animal waste from their cattle to make biogas for cooking. Not only would the project take care of the environmental threat from the burning of firewood, but it would also solve the problem of animal waste management in the dairy-producing town.

In order to utilize cow manure for this alternative cooking fuel, the group needed to build biodigesters, which are tanks that process the manure to produce a biogas that is mostly comprised of methane. (Learn about biodigester design and construction) The biogas is produced in the tank through the anaerobic (which means 'in the absence of oxygen') digestion of the manure by bacteria. These bacteria, which thrive in underwater, oxygen-free environments, consume the animal waste, reproduce, and give off a methane-rich waste. This biogas bubbles up from the depths of the manure/water mixture and escapes through the surface above. the biogas is then trapped by a large plastic balloon that hovers over the tank. Then, in the middle of the plastic, PCV tubing connects the biogas source to the kitchen, where the gas range (see picture at top of page) is ready to supply the alternative energy for cooking.

With the aid of a donation from the UN Women's Group in Vienna, Austria and the technical assistance of the Agriculture Ministry office in Guatuso, the Santa Fe Women's Group was able to build 16 biodigesters in 2006. The women of Santa Fe, however, are not finished with this important biogas project. They are still dedicated to increasing energy independence through biogas by extending the privilege of a biodigester to other deserving families in Santa Fe and the greater Guatuso area. To know more about biogas and biodigesters, explore the following links:

• Learn about biodigester construction - See the biodigester design that the women's group used for its biogas project that was featured in the Summer 2007 issue of the Permaculture Activist.
• Biogas and Biodigester FAQ's - Learn the basics about biogas and get some of your specific biogas questions answered.
• Video on how to make an anaerobic methane digester - Transcription of the English translation with link to the video.
• Video on biogas in Pune, India - See how biogas works in this Indian city where they use leftover food, instead of manure, for their biogas energy needs
• Video on biogas digesters in Tamil Nadu, India - See how this rural Indian state utilize its abundant raw materials to create energy independence through biogas.
• Video of the UC Davis Biogas Plant - Interesting large-scale biogas plant that processes solid organic wastes with minimal preparation.
• Read our collection of online biogas articles - Learn about biogas in other parts of the world from a newly-updated compilation of online biogas articles.
• Sintex Industries' new family-size biogas digester - Learn how biogas is gaining traction in India with the help of Sintex Industries and subsidies from the Indian government.
• Learn how to make your own homemade biodigester - This book offers an easy-to-use, step-by-step illustrated manual on how to make your own homemade biodigester to create biogas in your very own backyard.
• Cow Power - This is a short video that speaks to the importance of biogas production.
• What is Anaerobic Digestion? - A video introduction to the biogas production through anaerobic digestion.