Diversified and Integrated Food - Energy Systems
Developing production systems which also meet the energy requirements of smallholders is also important. However, three billion people – about half of the world's population - rely on unsustainable biomass-based energy sources to meet their basic energy needs for cooking and heating, and 1.6 billion people lack access to electricity (IEA, 2002. World Energy Outlook. Chapter 13. Energy and Poverty). In rural communities in developing countries this often results in encroachments into natural ecosystems, for example the cutting down of forests for fuel, leading to major sources of emissions. Integrated Food Energy Systems (IFES) aim at addressing these issues by simultaneously producing food and energy. This generally translates into two main methods. The first combines food and energy crops on the same plot of land, such as in agroforesty systems for example: growing trees for fuelwood and charcoal. The second type of IFES is achieved through the use of by-products/residues of one type of product to produce another. Examples include biogas from livestock residues, animal feed from by-products of corn ethanol, or bagasse for energy as a by-product of sugarcane production for food purposes. While simple IFES systems such as agroforestry or biogas systems are widespread, more complex IFES are less frequently implemented due to the technical and institutional capacity required to establish and maintain them, and the lack of policy support. Solar thermal, photovoltaics, geothermal, wind and water power are other options and can be included in IFES, despite the high start-up costs and specialized support required for their installation and servicing.
|National Biogas Programme, Viet Nam |
Viet Nam embarked on an integrated land management scheme, following land rights being given to individual farmers. This is supported by the Vietnamese Gardeners' Association (VACVINA), which works at all levels, and has national responsibility to promote this concept – called the VAC integrated system. It involves gardening, fish rearing and animal husbandry, to make optimal use of the land. Traditional fuels such as wood and coal for cooking are becoming increasingly scarce and expensive, and can contribute to deforestation. Increasing livestock production in rural communities with high population density leads to health and environmental issues from the quantity of animal dung being produced. Biogas digesters are part of the solution offered by this initiative, using the waste to generate energy, and the resultant slurry can be used as a fertilizer to improve soil quality. A market-based approach has been adopted to disseminate the plants and the service provided to those buying the digesters is comprehensive. The customer must have at least four to six pigs or two to three cattle that provide the animal dung. They pay the total installation cost for the digesters to local service providers, and operate the biodigester using instructions provided by them. A biodigester produces enough daily fuel for cooking and lighting. It improves the surrounding environment, whilst livestock produces meat, milk and fish products for local consumption and subsistence farming.
Source: FAO/Practical Action, 2009.
|Sustainable food and charcoal production in agroforestry systems, DRC |
Kinshasa, the capital of the Democratic Republic of Congo, has a population of eight million inhabitants and consumes up to 6 million tonnes of bioenergy equivalent per year. The city is surrounded by grasslands and patches of forest. The bioenergy used by the urban households consists mainly of fuelwood (charcoal and firewood). Charcoal needs, but also most of the staple starchy foods in the diet (cassava and maize), are provided by slash-and-burn shifting cultivation and by carbonization of the patches of forest and tree savannahs, which continue to deteriorate. Production obtained from these tree stands is becoming scarce and expensive. Soil fertility is declining, crop yields after fallow are decreasing, springs are drying up and fires are increasingly frequent. Slash-and-burn cultivation gives rise to tree fallow after one to three years of cropping, due to the exhaustion of soil reserves. Improving tree fallow consists in planting tree legumes, whose roots combined with microorganisms fix atmospheric nitrogen. Organic matter and nitrogen storage in the soil is thereby accelerated.
|Biogas in Thailand |
Methane from pig waste represents the largest source of livestock GHG emissions in Thailand with the number of pigs in the country expected to more than double between 2000 and 2020. A pilot project on ten pig farms with a total annual average pig population of around 131 200 pigs will reduce methane emissions from pig waste management by the installation of anaerobic treatment systems that recover biogas for use as energy. The total emission reductions are estimated at about 58 000 tons of Carbon Dioxide (CO2) equivalent per year (tCO2e/year). The project is partly financed by these reductions through a Clean Development Mechanism of the Kyoto Protocol. The electricity produced is expected for on-farm consumption. Sludge material will be dried and sold as fertilizer and soil amendment. In addition the project includes specific component activities for the community such as street lighting, access to drinking water, scholarships, mosquito spray machine, community shop, capacity building. This project is implemented by the World Bank and FAO. It is part of the Livestock Waste Management in East Asia project which global environment objective is to reduce livestock-induced, land-based pollution and environmental degradation.
last updated: Thursday, December 30, 2010