Biogas

Learn about biogas and its benefits. Biogas is derived from anaerobic digestion, which is the microbial breakdown of organic matter - known as feedstocks - in the absence of oxygen. Common biogas feedstocks include agricultural residues, food scraps, manure, and municipal wastewater. Biogas can be used for electricity, heat production, and cooking fuel. A purified version of it - biomethane - can also be used as vehicle fuel. Anaerobic digesters are systems used to produce biogas and vary in size and use. They range from industrial-scale municipal food waste, commercial livestock, and wastewater facilities to modular and micro installations for homes and even schools and small businesses. A by-product of biogas is digestate, an organic fertilizer and alternative to fossil fuel-based fertilizers. While biogas holds some potential for replacing fossil fuels, especially in hard-to-abate sectors, its role in the energy transition should not be overstated (see next section). Harnessed regeneratively and on a community scale, biogas has the potential as a solution for reducing fossil fuel use, cutting waste and pollution, re-localizing and decentralizing food and energy production, boosting local livelihoods, improving nutrient cycling and even enhancing soil health and reducing deforestation.

• The primary benefit of biogas lies in its ability to convert what would otherwise be waste - and its resulting emissions - into usable electricity, heat, and fuel. In Kenya, there are over 17,000 household biogas systems turning waste into a source of fuel and energy for homes.
• Digestate is often returned to agricultural lands as a nutrient-rich fertilizer. The digestate must first be properly treated and tested to ensure it’s appropriate for local soil conditions. In the EU, a new Soil Health Law is considering the role that solid digestate can play in replacing chemical fertilizers in food systems, with benefits for soil fertility and closing the loop in nutrient cycles.
• Biogas systems vary in size and type, from small-scale community and family digesters to industrial-scale installations. This farm in Brazil uses a small biodigester to produce gas and fertilizer, while industrial biodigesters, like this one on a hog farm in the USA, have caused significant damage to local wetlands and severely contaminated its watershed.
• While it is thought that biogas has been used for centuries, it has been growing significantly since the 1990s, with a strong uptick since 2022, as countries seek to diversify their energy mixes and bolster energy security. Europe is currently the region that produces the most biogas, followed by China and the U.S. It is estimated that currently, only 8 percent of biogas potential is being utilized globally.
• Biogas can be the embodiment of regenerative principles if the systems are designed according to bioregional and socio-cultural contexts. This article considers how biogas can be harnessed regeneratively through the lens of permaculture principles and describes how it has been applied on the Maya Mountain farm in Belize.
• Used prudently, biogas has the potential to contribute to the creation of local, circular economies by cycling local municipal and agricultural waste to produce a source of localized energy. In order for it to be truly circular, methane leakages must be avoided, and feedstocks must come from already extant, local sources.
• When biogas is paired with agroecological practices, it can have a cascade of benefits for climate mitigation, biodiversity, soil health, and local energy independence and livelihoods. Agroecological Symbiosis (AES) is a localized food production and consumption model that integrates biogas in a regenerative, circular system. The Palopuro project in Finland is a pioneering example of AES (see Agroecology Nexus).
• Agroecological Symbiosis integrates farms, food processors, and energy producers in a mutually beneficial, reciprocal system, generating only enough energy for production and selling any excess to the wider community. Because the system is limited by its bioregional context, it encourages re-localization, strengthening people’s connection to place and a localized food culture (See Localization Nexus).
• Biogas can also be harnessed in more isolated, rural communities in low-income countries to boost energy autonomy, local livelihoods, and biodiversity. In communities in Tamil Nadu, Karnataka, and Andhra Pradesh in India, biogas has replaced the need for firewood, thereby reducing deforestation and providing quality organic fertilizers enhanced by vermiculture (See Vermiculture Nexus).
• Biogas can be harnessed to supply fuel and fertilizer on a family and community scale. This regenerative biogas system, which is paired with algae ponds, integrates waste disposal, nutrient cycling, and biogas production for a single-family home.
• Decomposing waste in landfills produces significant amounts of the planet-heating greenhouse gas methane. Biogas can be a way to capture that methane and convert it into energy. In places like India and Bhutan, local projects like this help to manage a growing amount of landfill and organic waste while providing an alternative source of fuel.

Learn about the impacts and challenges of biogas. Biogas is gaining increasing attention as a means of decarbonizing energy systems and managing waste. However, conventional approaches to biogas development have significant climate, ecosystems, and social impacts. Biogas should not be used as a justification for producing more waste but rather only to utilize extant and unavoidable waste.

• Biogas is often touted as being a renewable energy. However, this perspective doesn’t take the entire lifecycle of biogas into account. Burning biogas emits greenhouse gasses and harmful pollutants and often leads to land-use changes, when land that could otherwise be left to nature is used for growing primary energy crops.
• Biogas installations with the greatest capacities are located on industrial-scale dairy livestock farms or Concentrated Animal Feeding Operations (CAFOs). As such, biogas can perpetuate industrial agricultural practices by expanding operations, thereby increasing pollutant run-off, methane emissions, and biodiversity loss.
• Biogas often favors major agri-businesses rather than small-scale farmers, providing justification for large companies to increase the size of their operations while claiming to use sustainable methods. Fossil fuel companies also use biogas for greenwashing and as a tactic to delay moving away from fossil-based energies.
• Biomethane - also known as “Renewable Natural Gas” or RNG - is a refined version of biogas. In Canada and in the EU, biomethane is being used by gas and agri-food companies to greenwash, push back against the transition to renewable energy, and to perpetuate industrial agriculture.
• Biogas can have a number of negative downstream impacts on ecosystems and local communities. Burning biogas emits harmful pollutants like hydrogen sulfides and ammonia and can also lead to acidification and eutrophication of water systems, with severe health consequences for local residents.
• Studies have shown that CAFOs are often disproportionately located in low-income and racially marginalized communities, with significant impacts on social and environmental justice. This study looks at how biogas plants in Thailand and the USA have exposed local communities to a number of harmful pollutants.
• The life-cycle emissions impact of biogas often depends on the type of feedstock used. Biogas produced from maize silage can be worse from an emissions perspective than fossil fuels, while biogas derived from wastewater sludge can have a negative carbon intensity.
• The combustion of biogas emits greenhouse gasses, and methane emissions from leakages in the supply chain - particularly from the digestate - exceed those from oil and fossil gas.

Support and participate in local, community-led biogas projects. Individuals and local communities can play their part in ensuring the development of biogas benefits people and nature. Avenues for action include developing small biogas systems in your home and communities, as well as taking political action against damaging and greenwashing practices by fossil fuel and agri-food businesses.

• Building your own biogas digester for your home or neighborhood can be done relatively simply and inexpensively, turning your waste into cooking fuel and energy. This article has some tips and inspiration on building a digester, while companies such as HomeBiogas sell ready-made systems for households and businesses.
• Share success stories on social media and in your local press about biogas being used as a local, regenerative solution, such as the Palopuro project in Finland. You can get in touch with the founders of the project - Markus and Kari - and get advice on how to start something similar in your own communities.
• Petition against industrial-scale biogas plants and raise awareness about corporate greenwashing around biogas from fossil fuel and agri-food businesses. There are many active campaigns you can support and helpful resources you can use, including this report and this article.

Harness biogas as part of a wider agroecological transition in your operation. Biogas can be a means of converting agricultural waste - such as manure and crop residues - into fuel, electricity, and fertilizer. However, it also causes significant harm to local communities and ecosystems and can even result in financial difficulties for farmers. Seeing biogas as part of a transition to regenerative agricultural practices can enable farmers to better manage their waste, generate an additional source of income, and improve the health of their soils.

• Go beyond simply integrating biogas into your operation by combining it with agroecological practices (see Agroecology Nexus). Using Agro-ecological Symbiosis (AES), a model that integrates and relocalizes energy and production, the Palopuro project in Finland has enabled farmers to become net energy producers and make additional income from selling the excess.
• While biogas can capture methane from agricultural waste, burning methane releases potent greenhouse gasses, which have so far contributed to about 30 percent of the rise in global temperatures. Significant amounts of methane are also emitted as a result of leakages during the storage and transport of biogas, so investing in high-quality and well-maintained infrastructure is critical.
• Using biogas to expand the size of operations - be that livestock or growing energy crops for use as feedstock - is incompatible with resilient and future-proof food systems. This handbook offers guidance on more sustainable approaches to biogas use on farms, including using catch crops and preventing leakages.
• A byproduct of biogas production - digestate - can provide your farm or business with a readily available alternative to fossil-based fertilizers. Because applying digestate directly to the soil can lead to fugitive emissions, it should first be treated and checked to ensure it’s appropriate for local soil conditions. Integrating biogas with algae production in agricultural operations can be an effective way to treat digestate and avoid run-off.
• Many conventional biodigesters require large inputs of agricultural feedstocks, as well as considerable maintenance and cost. Micro-digesters can be an alternative for small-scale farmers with less financial flexibility.

Support small-scale, community-led biogas projects in rural communities. Biogas can play a role in boosting local livelihoods, decentralizing energy production and reducing deforestation. It can do so by substituting for wood as a fuel, particularly in isolated, rural communities in low-income countries. Projects should be tailored to their bio-regional and socio-cultural contexts, and locally owned and managed.

• In rural communities, particularly in low-income countries, biogas can offer a means of managing agricultural waste and providing a reliable source of energy. A UNDP-supported biogas project in Rwanda has helped to reduce deforestation by replacing traditional dependence on firewood.
• Capital costs for setting up small-scale biogas systems are particularly high in low-income countries. Providing financial support for small-scale biogas projects like those run by the AEJT non-profit can boost local livelihoods and energy independence while ensuring local ownership and sustainability.

Consider biogas as a solution for managing waste and supplying an alternative source of localized energy. Used on a small, local scale, biogas can be an effective way to manage your waste and convert it into something useful while also helping you save money by using (and possibly even selling) the energy and fertilizer it produces.

• As a homeowner, you can build small biodigesters to turn your kitchen scraps and garden residues into fuel. Here’s a step-by-step guide on how to build a digester, and a video explaining how home-scale biogas systems work. There are also ways in which you can convert human waste into usable cooking gas, as well as fertilizer, as in the example of the Aanandaa Permaculture farm.
• Small-scale biogas systems can also be used in offices, municipal facilities, restaurants, hospitals, and schools, providing an alternative to fossil gas and a solution for managing waste. Working with local residents in Koramangala, India, Carbonlites installed small-scale digesters to turn community waste into gas and fertilizer, which is used by local businesses and farms.

How rotting vegetables make electricity (6 mins.)

What is Palopuro symbiosis? (3 mins.)

How to build a methane biodigester (14 mins.)

The problem with biogas (2 mins.)

The basics of small-scale biodigesters (2 mins.)

Agribusiness is trying to greenwash its waste as “renewable energy”

Swedish break-through or community-run micro-biogas in Europe

How to run a profitable circular farm

Self-sufficient organic Finnish farm grows its own fuel and a greener future

The biological cycle of the butterfly diagram

Biogas and its role in the energy transition

Six reasons anaerobic digesters aren’t as environmentally-friendly as you think they are

Is biogas a “green” energy source?

Biogas or Bull****?

Biogas can help the world cook sustainably

Digestate and compost in agriculture

What is an agro-ecological symbiosis system? (8 mins.)

The methane digester money trail: who’s making money off of biogas? (37 mins.)