Sustainable biogas production in South African rural households

The main objectives in the long term are that anaerobic digestion (AD), or biogas production will help alleviate energy poverty in rural Households in South Africa, enhance food security, prevent deforestation, reduce GHG emissions and at the same time mitigate the effects of climate change. Anaerobic digestion is a process that can control odours, kill pathogens, limit nitrogen losses, mineralize nutrients and provide energy from livestock manure and organic wastes. The technology will also give employment opportunities and reduce poverty, reducing the number of hours spent by women and children on collection of firewood. Situation analysis has been a very significant part of the project as it is done in the form of survey to investigate the resource availability in communities, household energy needs and general household information. It also allows the project implementers to interact with the community members. The survey gives the overall context of the villages and the potential beneficiaries. Capacity building training workshops was conducted successfully. The purpose of the workshop was to give biogas awareness, train farmers on biogas production and integrated crop-livestock system and measuring of weather elements. Different presentations were given by ARC officials, these presentations included 1) Overview of the project 2) Workshop training manual and 3) Situational analysis report back. Farmers showed interest in presented materials as evidenced by 100% attendance by targeted beneficiaries. There was also highly successful training on installation of biodigesters that targeted youth in villages around the project sites. Weather instruments in farms is important in quantifying the agricultural potential of the farm and in each of the farms measuring instruments were installed. The benefits of the project extended beyond the project beneficiaries with a number of youth being trained in the installation of biogas digester and maintenance of the biogas system. The other main impact of the project was to create temporary job opportunities. With almost 90% of the youth in the rural areas being unemployed, the opportunity is highly appreciated by the community members regarding the project as the main income generation of most youth in the project sites. Other important activities in 2016 have been performance evaluation of installed biogas digesters and the investigation of the biogas production system. More research and capacity building to improve the performance of biogas digesters under different climatic conditions is needed. Stable supply of biogas from cattle manure in the winter season without heating is a challenge that may be alleviated by supplying the reactors with more easily degradable substrates, but more research on this topic is recommended. Another challenge may be where to find these substrates in the winter season. Possible solutions are silage of water hyacinth and slaughterhouse waste. The setting up of a biogas laboratory at the Institute of Soil Climate and Water (ISCW), Agricultural Research Council (ARC), has been completed and the achievements in capacity and competence building at ARC will not only be very important for improving people's living standards in rural areas, and for developing the local economy, but it will also have great potential to contribute to the success of implementing sustainable biogas production on a much larger scale. The attributes of the biogas technology go beyond the production of gas, with added benefits like the conversion of organic waste to high-quality fertilizer and sanitation improvements. In South Africa very little research work has been done on the use of biogas slurry as a soil amendment both at commercial and communal scales. Application of the bio-digested slurry to the soil can be of benefit to crop production. Another objective of the Rubiosa research project has therefore been to investigate effects of biogas slurry on soil quality of selected South African soils and to develop guidelines on application of biogas slurry. In the field trials, the emergence of the crops varied from one treatment to another, but overall it took just over 7 days for them to emerge. The emergence was over 95% for the maize for all crops. Weeds coverage ten days after emergence ranged from 5 to 30 %. There were no signs of pest infestation (5 %) except in the maize trails were the crop was attached by full armyworm 3 weeks after the planting date. Overall plant health was good. Irrigation was done 3 times a week were this enabled the crops to grow healthy for all trials. Monitoring and evaluation was done weekly and when necessary mechanical weeding was done. Organic amendments (biogas slurry and animal manure) showed potential of better growth compared to control (no fertiliser application) although chemical fertiliser showed good growth. However, the project has been too short to fully exploit the potential of digestate as fertilizer.

Immediate and concerted action from researchers, stakeholders and governments are needed to mitigate and combat emissions from livestock production and at the same time replace fossil fuels with environmentally sustainable energy sources. Anaerobic digest ion is a process that can control odours, kill pathogens, limit nitrogen losses, mineralize nutrients and provide energy from livestock manure and human litter. The current situation in Norway and SA today is a low adoption of the biogas technology. The h ypotheses are that the technology, when adopted on a wide scale will contribute to reducing the GHG emissions through substitution of carbon dioxide neutral biogas with fossil fuel and emission of methane from manure storages, and in SA also through preve ntion of deforestation. Implementation of anaerobic digestion on a large scale at mesophilic temperatures is limited by the high cost of digesters, high running costs in form of supplied energy, and technical skills required operating such systems. Simpli fied versions of biogas reactors will be developed with the aim of reducing volume and cost. In cooperation with a rural biogas installation company (Pioneer Plastics), biogas technology will be further simplified and extended for application where infras tructure is incompatible with application of complicated reactors. The study is designed to obtain key information for optimising biogas production rates and yields. The technology will also give employment opportunities and reduce poverty, reducing the n umber of hours spent by women and children on collection of firewood and increasing the research capacity on biogas at graduate and postgraduate levels. A multi-disciplinary approach will be employed, executed by a team consisting of various disciplines w ith the community taking an active part in the research activities. This will ensure that different barriers to technology dissemination and acceptance are adequately investigated and addressed.