Junzi Shi is a Chemistry and Global Health student at Northwestern University. As a team member of her school’s Engineers for a Sustainable World (ESW) chapter, she traveled to Nicaragua in March of 2009 to install household sized biogas digesters with Green Empowerment, AsoFénix, and families in two rural communities. In May 2009, Junzi traveled to Peru with Green Empowerment to participate in a Design Exchange on Small-scale Biogas Digesters in Latin America. In June 2010, Junzi will lead her own ESW team on a ram pump project in the Philippines with Green Empowerment and the Alternative Indigenous Development Foundation.
As we descended in the small plane towards Cajamarca, Peru, the thick white clouds seemed to cling to the earth, hugging its surface and nestling in the ridges of the mountainous terrain. The passengers saw lush green pastures and hillsides crowded with crops, and they felt the frugality of the farmers as well as their close relationship with the land. It was my first time in South America and as we stepped off the plane, the northern highlands of Peru gave me a beautiful impression of the country. Peru, a nation with 7.5 million people living in rural provinces and 72.1% of those living in poverty (source: Rural Poverty Portal, Peru), has been on the forefront of environmental sustainability in order to improve the way of life and also hold responsible practices.
The Biogas Design Exchange was held at the Center for Demonstration and Training of Appropriate Technologies (CEDECAP) located in the outer periphery of Cajamarca. It was the first conference of its kind, a wonderful chance to share knowledge and experiences with 33 individuals from 10 different countries. The first two days were filled with presentations that revealed how practices involving the same technology could differ in many ways. For example, the source of fecal matter for biodigesters can come from pigs, cattle, humans, or unusual livestock such as guinea pigs. The design of the digester also varies in shape, size, and building material depending on the use of the final products. Many farmers in Bolivia, Mexico and Peru – such as Juan Morocho – use methane for cooking and the liquid/solid products as fertilizer. During my stay in Bramadero, Nicaragua, the families reported an increase in crop growth after applying the fertilizer, having recently introduced more vegetables and protein in their diet. This is a great way to use all the products of the biodigester system. However, in highly commercial enterprises, I found it surprising that methane gas is simply burned when it could be put into electricity, heat and other domestic or commercial uses.
The next two days were spent installing two different sausage-style models of digesters at the National Institute of Agricultural Investigation. The long and narrow PVC model was placed parallel and adjacent to a high density polypropylene model in order to test several factors. Although the former may generate gas faster because it has greater overall volume and above-ground surface area, the latter is expected to have a longer lifetime due to the more resilient material. In Nicaragua, we installed four Indian-style digesters made of ferro-cement and one sausage-style model made of polypropylene. Although cement can crack over time, ferro-cement was advantageous because it was internally reinforced with chicken wire, and the locals had had previous experience with the material. Polypropylene digesters are advantageous due to their long lifetimes of up to 20 years, but the material is not readily available in many countries.
The last day of the conference was spent in round table discussions regarding management, technology, selection of families, and future research. Although it is important to consider a family’s living conditions and the farm layout, it is also essential to consider the community at large. In Nicaragua, our team worked with GE in villages where previous water, wind, and solar technology had been established. Also, the biodigester could be supported by a committee of community members who were invested and worked to maintain the installations. My experiences in Nicaragua and Peru have taught me that biogas digesters involve a great deal of “the human factor” in addition to engineering calculations, sometimes more so. For instance, after the installations were completed and started generating gas, some Nicaraguan families would not use the improved gas stove because they preferred the wood-smoke flavor that comes from traditional cooking with wood-burning stoves. Cultural factors such as this can really prove to be a challenge to the successful adaptation of technology.
The Design Exchange established a precedent that, I hope, will be the start of many conversations amongst leaders of biogas around the world. As my friend Juan says, there are many good people in the world, but sometimes they don’t know about each other. It is essential to make these connections and share our knowledge with others so that we can achieve our common goals all the better. Each man can build his own house, but many men can build a city. After my experiences in Nicaragua and Peru, I have gained more respect for the work of fearless individuals and NGOs who rise over countless obstacles to achieve their vision.