Design and Evaluation of a Sustainable Energy System for AETCR Llanogrande, Colombia

Sammanfattning: After many years of conflicts and civil wars between the guerilla group called FARC and the government of Colombia, a peace agreement was signed in 2016. The peace agreement included six cornerstones, and in this study the third one was in focus. It included ending the hostilities and promoting the laying down of arms, in exchange of a chance for the ex-combatants to reintegrate into society. Special reintegration villages were formed, also called AETCR’s today, and ARN was the presidential agency that managed the villages. In the reintegration process, the ex-combatants were provided with work opportunities and education, and a stable and functioning energy system was of great importance to ease the reintegration. The purpose of the study was thereof to propose a sustainable energy system for AETCR Llanogrande, that would ensure energy stability for the ex-combatants to reintegrate into the life of civilians. The aim and objectives were to maximize the social benefits, reduce the environmental footprint and minimize the economical costs. Two research questions were formed, regarding what would be the best energy system when focusing on the objectives separately and what would be the best design for all three combined. The study was a pre-study based on a previous project at the Royal Institute of Technology, and was performed with a qualitative research method, with both inductive and deductive approaches as well as a field study. The field study was supervised by the ARN Administrator and Engineer Mr. Fernández, who was also one of the contact persons in AETCR Llanogrande. Information regarding the AETCR was provided by both Mr. Fernández and the ARN Coordinator Carolina Sofía Rodríguez Rodelo. The available renewable energy resources were evaluated, and it was concluded that wind power was not a feasible option for energy production. Although, the solar resources were good and biomass was available. With all the attained information regarding the AETCR, several scenarios were formulated; one for Business As Usual, one that included a Modest Implementation of Technologies, one that was Off-Grid, one with a Social Development with a Constant Population, and one with an Increased Energy Demand with a Growing Population. A literature study was performed for the different technologies; solar, micro-hydro, biodigesters, generators and energy storage. The field study for hydro was performed, and it was concluded not to be feasible. A load curve was created for the AETCR, with varying daily demands for the different scenarios. The electricity system was simulated in HOMER Pro, where the weather data was collected from PVGIS. Based on the technology research, the fixed dome biodigester was recommended and calculations regarding the biogas production were performed in MATLAB. The economics were also evaluated for both systems, where the net present cost (NPC) was the prioritized factor. The lifetime emissions were also calculated for both systems along with the renewable fraction (RF) in the electricity mix. For the electricity system it was concluded that polycrystalline panels, with the grid and the generator, as well as Li-Ion batteries or no batteries was the most beneficial combination, both concerning the economics and the environment. The size of the system however, was flexible in terms of what requirements were desired for the AETCR, such as the RF and self-sufficiency for example. The chosen biodigester design was the chinese design with a diameter of 4.8 m. This was the recommended system for all of the scenarios when looking at both the economical and environmental aspects. The social impact was not possible to measure, and it was instead discussed. Finally, a recommended combined system was proposed. The electricity system consisted of 36.8 kW of polycrystalline PV panels, 20.5 kW inverter capacity, no batteries and a total RF of 83.2%. Combined with the previously mentioned biodigester which produced 140,300 m3 of biogas in a year, the total NPC was 724 kUSD and the lifetime emissions were 585.4 tonnes CO2-eq, concluding in a NPC increase of 7,000 USD and a reduction of 374.3 tonnes CO2-eq. A sensitivity analysis was also performed to evaluate the effects of the various input parameters. In conclusion, the combined system was deemed possible to implement and that it would support the reintegration of the inhabitants of AETCR Llanogrande in a sustainable way.