The Sichuan Household Biogas program of activities protects the climate and human health and well being in several ways. The project reduces risk of disease animal waste, replaces coal with free, clean burning, constantly renewable biogas made from the animal waste, provides substantial improvements to indoor air quality, savings on health, energy costs, and affords local women employment opportunities and young children the capacity to go to school.
Rural households in Sichuan traditionally use either coal or firewood as cooking fuel. Not only do these practices produce CO2 emissions but also severe indoor air pollution. Households that take part in this project are small farms that raise pigs and typically store the pig manure in traditional pits below or beside the animal confinements. These open pits generate methane emissions, as well as pose severe health risks for both animals and humans alike. These manure pits are sources of zoonotic diseases that can be passed from animals to humans.
In order to mitigate the air pollutants generated from burning coal, provide a better indoor environment, and improve sanitation to needy rural communities, this Household Biogas project aims to maximize the usage of animal manure and turn it into a cleaner, more convenient, fully renewable and less costly cooking fuel. By installing a biogas digester (a closed structure that captures waste and the gas waste emits) with an inlet pipe directly connected to the animal barns, the households can sweep the manure directly into the digester without any further contact. Both the odor of the degrading manure and the risk of infections are greatly reduced, as it is stored in the septic tank of the digester.
This project also helps reduce the time spent by women collecting firewood or traveling to purchase fuel, and reduces the amount of household income spent on cooking fuel. Due to the reduction of methane emissions originating from the pits and of carbon dioxide emissions caused by the common use of coal and wood as cooking fuel, the 2,000 chosen households account for an annual GHG emission reduction of approximately 4,500 tCO2e (tonnes of CO2 equivalent). Moreover, the manure treated in a biogas system has a much higher fertilizer quality than manure originating from incomplete digestion processes in the commonly used pits.
Biogas is generated in the digester and delivered to the gas cooker through a rubber hose. As long as there is gas in the digester, it can easily be extracted and is available within seconds. Without this project, households would need to keep sufficient stock of coal and wood. The biogas generated from the digester is constantly available and does not need to be stored, nor purchased so long as the families keep pigs. Furthermore, the gas cookers can simply be switched on and off—there is no waste—the design is incredibly efficient. The project can even result in more efficient cooking times as there is no longer a need to wait for fires to reach full heat.
The Sichuan PoA improves the lives of 395,435 families, reduces nearly 340,000 tons of coal reduced annually, and has reduced global emissions by more than 2,179,495 metric tonnes of CO2 equivalent (tCO2e) since inception.
“Our home is now free of smoke, flies and smells. It is also much more convenient for me to manage our family business while taking care of the cooking. With more pigs we would even be able to use the biogas for lighting and heat water for the shower.”
— Household Ms. Huang Mingying (digester installed in 2012)
“Biogas is hygienic, convenient, free-of-charge and is available all the time. It is also much cleaner than firewood. We have been able to use it to cook all the time.”
— Household Ms. Zeng Yuying (digester installed in 2011)
Sichuan Province, China
Clean Development Mechanism (CDM), Gold Standard
European Union Registry