Turning Waste into Social Change

Wood-burning stove, rural Paraguay

Wood-burning stove, rural Paraguay

For each hour that a woman living in rural Paraguay spends cooking with a wood-burning stove, she inhales a quantity of smoke and toxins that are equivalent to 200 cigarettes.

While in school I learned about the health risks low-income, rural populations face when cooking with wood-burning stoves, and that knowledge compelled me to research alternative cooking technologies that are affordable and sustainable. I also found out there are solutions to this problem like anaerobic digestion, commonly known as the biodigester: a simple and affordable system that produces methane gas for cooking and fertilizer for farming.  It appeared that transitioning to this technology could be a way to achieve environmental justice for people like the woman in rural Paraguay who are usually left out of the sustainable development picture.


A biodigester recipient, Nari, watches as the final steps are taken to install his biodigester. In this photo the bag is being filled with material for the first time.


This is a complete biodigester. The black material covering the bag protects it from natural elements to ensure its longevity.

Biodigesters function like an artificial stomach. There is a long, heavy duty plastic bag that captures organic material – such as cow feces – and produces methane, a flammable gas.  This gas is transported to a stove by way of a pipe system and can be released for use with the turn of a valve, which mitigates the health concerns of the wood stoves. The excess material produced by the biodigester can be used as valuable fertilizer that can be spread in gardens or sold for extra income. The only requirement for ownership is having access to the excrement of two-to-three farm animals.

If you are interested in learning more about bidogesters, please visit the EPA’s AgSTAR website, which has promoted the use of biogas recovery systems to reduce methane emissions from livestock waste for over 20 years!

Upon discovering this technology a team of fellow students and I applied for and received funding from the Georgetown University Social Innovation and Public Service Fund and the Georgetown International Relations Association’s Global Generation Grant to install biodigesters in the homes of five randomly selected families in Aregua, Paraguay.  This project aims to improve the lives of those who receive biodigester technology, while collecting data on biodigester feasibility, usage, and maintenance.  We hope to promote the use of biodigesters in Paraguay by educating local communities about the health hazards of wood-burning stoves.

Click on the photo to view this infographic that illustrates 20 years of growth and accomplishments achievement throughout AgSTAR's history.

Click on the photo to view this infographic that illustrates 20 years of growth and accomplishments achievement throughout AgSTAR’s history.

The benefits of biodigesters extend beyond respiratory health. By eliminating the need to collect wood for wood-burning stoves, deforestation is also prevented, which helps preserve the local habitat and limits consequences of receding forests such as water run-off and destroying local habitats for animal populations.  The atmosphere also benefits as biodigesters don’t emit black carbon, a nasty bi-product from wood-burning stoves. Additionally, by collecting animal refuse for biodigesters, communities will prevent the run-off contamination of waste into their local water supplies.

Nancy demonstrates using her bio-gas powered stove.

Nancy demonstrates using her bio-gas powered stove.

When we travelled to Paraguay to complete the project, we could not have been more pleased, not only by the local reception to biodigesters, but also strong indicators that the technology will achieve what it promises. For example, our team visited a family in Paraguay that has been enjoying the benefits of biodigester technology for three years.  The family’s mother, Nancy, has found that cooking is now more convenient and efficient.  She does not have to spend two-to-three hours a day searching for firewood to use for her stove.  Additionally, by not having to cook in a hazardous smokey environment, her eyesight has noticeably improved.  Before switching to the natural gas stove fueled by her biodigester, Nancy’s doctor said that her eyesight was so poor because there was grease in her eyes from cooking.

The family has also profited from the fertilizer their biodigester produces. With this fertilizer they were able to grow a full garden on soil that was previously too poor for producing crops.  As a result of the garden, the family saves money every week that they previously allocated to buying vegetables.

Nancy shares her experiences with Lauren

Nancy shares her experiences with Lauren

Through education, our team hopes that the benefits of this project can reach far beyond the borders of Paraguay as people learn about the impact biodigesters can have on their lives. Not only does AgSTAR provide information about biogas recovery but there are financing opportunities available to those interested in utilizing this technology domestically.

About the Author: Lauren Gros is a student at Georgetown University. She is currently interning for the EPA’s Office of Environmental Justice.

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