Alternative energy supply system to a rural village in Ethiopia

Abstract

Background: Most households in rural developing countries do not have access to modern energy supply. Household level biogas energy was considered as an option but failed due to lack of sufficient resources for its installation and operation. A community energy system can be an option, but most studies focused on off-grid electricity. This energy system cannot be a realistic option particularly for cooking demand. An efficient and suitable system matching local resources and demand expectation needs to be developed which this study focuses on assessing. Biogas and solar energy technologies are viable to establish such kind of a system since they can be converted to different forms of energy. Therefore, this study aims to determine efficient biogas and solar energy production and utilization options for small scale village energy application in rural Ethiopia. Methods: The efficiencies of the production and utilization options are determined based on the system configurations involving resource, conversion, and utilization combination models. We used local resources, data, and relevant literature information for the system analysis. Results: The analysis shows that most energy is needed in the form of heat for cooking and a smaller part in the form of electricity (about 10%). The community waste stream converted to biogas will be enough for cooking, but not enough biogas is left to produce enough electricity. Co-digesting altogether provides biogas that can meet only about 75% of the electricity demand. Concentrated solar cookers can be an alternative for cooking in areas where installation of biogas is not possible. About 2-m2 size solar concentrator is sufficient to meet each household’s cooking energy demand. The lighting and appliance energy demand can be met with photovoltaic (PV) energy produced with reasonably sized panels. However, the use of electrical energy for cooking produced with PV cannot be an economic option with the available technologies. Conclusions: The community energy system involving anaerobic co-digestion (biogas) and/or solar energy technologies is viable to meet the demand when efficient production and conversion is made based on specific local resource supply and demand.