Sustainable development covers three aspects of society - economic, social and environmental. Biogas contributes to these three aspects of sustainable development in the following ways:
Domestic biogas digesters contribute to economic development because:
- The expenses for domestic energy are significantly reduced.
- The labour required to maintain traditional energy systems (such as firewood collection) can be used in more directly economically productive ways.
- Substitution of petroleum products will reduce the countries foreign exchange demand.
- Application of bio-slurry increases the yield and reduces the need` -and expenses- for synthetic fertilizer.
- A vibrant biogas sector creates significant employment and related economic activities, particularly in rural areas.
- Reduced disease (human and animal) can improve productivity.
Domestic biogas digesters contribute to social development because:
- The reduction in domestic workload, particularly for women and children, increases opportunities for education and other social activities.
- Respiratory illnesses resulting from indoor air pollution and gastro-enteric diseases as a result of poor sanitary conditions reduce significantly.
- In rural areas, biogas digesters often initiate innovation (education, sanitation, agriculture).
- Increase awareness of alternative farming and animal husbandry practices and environmental impacts of behaviour.
Domestic biogas digesters contribute to environmental development as follows:
- Substituting conventional fuels and synthetic fertilizer, and changing traditional manure management systems, biogas installations reduce the emission of greenhouse gasses significantly.
- Bio-slurry improves soil texture, thus reducing degradation, and reduces the need for further land encroachment.
- Reduction of firewood use contributes to checking deforestation and reduces forest encroachment.
- Improved manure management practices reduce ground and surface water pollution and odour and improve aesthetics.
Biogas & the United Nations Millennium Development Goals (UN-MDGs)
Domestic biogas programmes contribute to reaching the UN-MDGs in the following ways:
MDG 1 Eradicate extreme poverty and hunger.
Target 1: To halve extreme poverty
In general, households who install biogas are not amongst the poorest of the poor due to the fact that for a biogas plant to function a household must have a minimum number of animals that is often more than a very poor family has. However, the biogas dissemination process and the resulting reduced claim on common ecosystem services do affect the livelihood conditions of (very) poor non-biogas households as well. For example:
Construction and installation of biogas creates employment for landless rural people
Biogas saving on the use of traditional cooking fuels increases the availability of these fuels for (very) poor members of the community
Pollution control and waste management benefit all members of the community
MDG 3 Promote gender equality and empower women.
Target 4: Eliminate gender disparity in education
It is predominantly women and girls who spend the most time and effort providing traditional energy services and using a domestic energy supply. Biogas directly benefits this group in the following ways:
Biogas can provide light that helps women and girls to extend the amount of time in the day that they can study and gain access to education and information or engage in economic activities.
Domestic biogas reduces the workload of women by reducing the need to collect firewood, tend fires and clean the soot from cooking utensils. This can save on average 2-3 hours per household per day
The reduced smoke from replacing traditional fire wood stoves with biogas can improve the health of women (and children) who are most exposed to the dangers of wood smoke.
The provision of biogas can provide an additional or more cost effective home based energy source that can enable women to participate in home based enterprises to generate additional income or at least generate income in a way that suits their life and obligations.
MDG 4 Reduce child mortality.
Target 5: Reduce by two-thirds the under-five mortality rate
Half of the world’s population cooks with traditional (mostly biomass based) energy fuels. Indoor air pollution from burning of these fuels kills over 1.6 million people each year, out of which indoor smoke claims nearly one million children’s (<5) lives per year. Diseases that result from a lack of basic sanitation, and the consequential water contamination, cause an even greater death toll, particularly under small children (<5 mortality caused by diarrhoea is approximately 1.5 million persons per year).
Biogas stoves substitute conventional cook stoves and energy sources, virtually eliminating indoor smoke pollution and, hence, the related health risks that particularly affect children who are often heavily exposed to indoor smoke.
Biogas significantly improves the sanitary condition of the farm yard and its immediate surrounding, lowering the exposure of household members to harmful infections especially children who spend extended periods in the farm yard.
Proper application of bio-slurry will improve agricultural production (e.g. vegetable gardening), thus contributing to food security for the community.
MDG 6: Combat HIV/AIDS, malaria and other diseases.
Target 8: Halt / reverse the incidence of malaria and other major diseases
Indoor air pollution and poor sanitary conditions annually cause millions of premature deaths.
Biogas virtually eliminates health risks (e.g. respiratory diseases, eye ailments, burning accidents) associated with indoor air pollution.
Biogas improves on-yard manure and night-soil management, thus improving sanitary conditions and protecting freshwater sources, lowering the exposure to harmful infections generally related with polluted water and poor sanitation.
MDG 7 Ensure environmental sustainability
Domestic biogas can help to achieve sustainable use of natural resources, as well as reducing (GHG) emissions, which protects the local and global environment. Application of bio-slurry increases soil structure and fertility, and reduces the need for application of chemical fertilizer.
Target 9: Integrate the principles of sustainable development into country policies and program and reverse the loss of environmental resources.
Large scale domestic biogas programmes positively influences national policies on sustainable development (e.g. agriculture, forestation, poverty reduction)
Biogas programmes usually comply with and support government policies and programmes that have positive environmental impacts including pollution control, green house gas emission reduction and forestation
Target 10: Halve the proportion of people without sustainable access to safe drinking water and basic sanitation.
Biogas reduces fresh water pollution as a result of improved management of dung.
Connection of the household toilet to the biogas plant significantly improves the sanitary conditions in the farmyard therefore reducing the risk of water contamination.
Biogas and Greenhouse Gas (GHG) Reduction
Domestic biogas plants are installations used for fermentation of mainly animal manure with the objective to generate biogas and bio-slurry that can be used by individual households for cooking or lighting and agricultural production respectively.
Domestic biogas installations - potentially- reduce greenhouse gas (GHG) emissions in three ways: by changing the manure management modality; by substituting fossil fuels and non-renewable biomass for cooking (and to a smaller extent for lighting) with biogas, and; by substituting chemical fertilizer with bio-slurry.
Manure management: The traditional manure management modality may include storage or discharge of animal dung under (semi-)anaerobic conditions, e.g. by deep pit storage or discharge of raw manure in sewage channels or lagoons. The anaerobic condition will cause the manure to (partly) ferment, in which case methane (CH4), a potent greenhouse gas, is emitted in the environment.
In a domestic biogas installation, the manure is immediately discharged in the installation. In the plant the fermentation of the manure takes place under controlled conditions, whereby the generated methane gas is captured and used for cooking. Technically, this process is referred to as “methane capture and destruction”, whereby the potent CH4 is converted in carbon-dioxide (CO2) and water. Although CO2 is a greenhouse gas, it is far less potent than CH4 and, more importantly, can be considered “renewable” as the CO2 is absorbed by the very growth of vegetation from which it originates.
Substitution of fossil fuel and non-renewable biomass: The domestic fuel mix of rural households in developing countries typically includes significant amounts of fossil fuel (kerosene, coal, LPG) and biomass (fuelwood, charcoal, dung cakes). The combustion of these traditional energy sources creates carbon-dioxide emissions (and to a lesser extent CH4 and Nitrous-oxide (N2O), emissions).
Fossil fuels, by definition, are non-renewable sources of energy. Hence, the full amount of GHG emission resulting from combustion of these energy sources results in a net increase of GHG in the atmosphere. For biomass, however, the situation is less straight-forward. As far as the burned biomass is obtained from renewable sources (agricultural waste, dung-cakes) the produced carbon-dioxide is assumed to be absorbed by the vegetation from which they originate. Therefore, carbon-dioxide emissions from renewable biomass do not contribute to the net GHG concentration in the atmosphere. Biomass obtained from non-renewable sources (referred to as “Non Renewable Biomass, NRB), however, do contribute to global warming. NRB includes e.g. fuelwood and charcoal whose harvest results in a reduction of forested area and therefore in a reduction of the carbon sink function of this area.
To the extent that biogas replaces fossil fuels or non-renewable biomass, this substitution then results in a reduction of greenhouse gas emissions.
Chemical fertilizer substitution: Many developing countries face a net outflow of soil nutrients and farmers apply chemical fertilizer to maintain the fertility of their soil. Although chemical fertilizer use in developing countries often is erratic and scattered, typically fair amounts of chemical fertilizer is applied. Production as well as application of chemical fertilizer has a GHG aspect, mainly as a result of the high energy requirement (often sourced from fossil fuels) for chemical fertilizer production and the Nitrous oxide (N2O) emissions.
The “by-product” of a biogas installation is “bio-slurry”. Bio-slurry is the digested dung that is discharged from the installation after the fermentation process. The fermentation process does not reduce the nutrient value (NPK-value) of the feeding material. In fact, when applied correctly, the fertilizing value of bio-slurry even surpasses that of raw manure. Therefore, bio-slurry is a good organic fertilizer that can replace or reduce the application of chemical fertilizer.
To the extent to which bio-slurry is actually replacing chemical fertilizer, GHG emissions are reduced. From an accountability point of view, however, this component of GHG emission reduction by domestic biogas installations may proof very cumbersome to substantiate.
GHG emission reduction potential of domestic biogas installations: The actual reduction of greenhouse gas emissions by domestic biogas installations depends on the local situation, the size of the installation and the way the installation is operated, whereas the “claimable” GHG emission reduction depends on the used methodology. However, results based on -tentative- calculations with data sets of biogas programmes in which SNV is involved and claimed reductions by other domestic biogas projects would indicate GHG emission reductions in a range of 1.7 to 5.9 tons CO2eq per installation per year. It has to be noted that the currently approved CDM - biogas projects are working under methodologies that have since been withdrawn.
Reducing global GHG emissions: In 1992, the United Nations Framework Convention on Climate Change (UNFCCC) was established to combat global warming. Subsequently, in 1997, the Kyoto Protocol (KP) was adopted to commit developed countries (annex 1 parties) to reduce their greenhouse gas emissions. This binding protocol eventually came into force in February 2006, following the ratification of Russia. The KP requires annex 1 countries to reduce their GHG emission to ~ 95% of their pre 1990-levels over the period from 2008 to 2012. The required GHG reduction, also know as the assigned amount units (AAUs), is measured in tons of Carbon-dioxide equivalent.
As global warming is a world-wide phenomenon; the geographical location of greenhouse gas emission reductions is irrelevant. Hence, the KP defined three “flexibility mechanisms” to achieve its emission targets economically:
The Emission Trading (ET) allows for annex 1 parties (industrialized countries) to acquire (buy, trade) emission reduction units from other annex 1 parties.
Joint Implementation (JI) allows annex 1 parties to implement GHG emission reducing projects in other annex 1 parties and count the resulting emission reduction for meeting their own KP target.
The Clean Development Mechanism (CDM) allows annex 1 parties to implement GHG emission reducing projects in non-annex 1 parties (developing countries) in return for Certified Emission Reductions (CERs) whereby host parties are assisted in achieving sustainable development (through “technology transfer”) and the ultimate goal of the Convention is supported.
By capping global GHG emissions and allowing trade in GHG reduction units, the UNFCCC, with its Kyoto Protocol, introduced a commercial, compliance-based market for greenhouse gas reduction. In the spirit of this compliance market, but also to circumvent the complicated and lengthy formal procedures, non-UNFCCC initiatives were launched as well.
These initiatives are normally referred to as the “Voluntary Market”. Voluntary projects are outside the Kyoto system; their emission reductions cannot be traded in official emission trading systems.
Most offset projects to date are developed in the voluntary market and do not follow a particular standard. Small projects will find the voluntary offset market increasingly attractive because projects are often cheaper to develop and implement than under the CDM.
They are attractive to companies who use offset as part of their corporate social responsibility strategy but which up to now are not legally obliged to lower their emissions. To distinguish between UNFCCC and voluntary emission reductions, emission reductions traded at the voluntary market are referred to as Verified Emission Reductions (VERs), similarly equalling one ton of carbon dioxide equivalent.