Sustainable Electrification System for Rural Farms in Zambia: A Case Study of a Farm in Lufwanyama

摘要

This paper focuses on investigating the most sustainable way of electrifying rural farms, taking a farm situated 20 kilometers from a possible grid connection point as a case study. The study area is located in Lufwanyama, a rural district on the Copperbelt provinces of Zambia. Despite that Lufwanyama is endowed with numerous natural resources, the district has seen little infrastructure development. Presently, the district's fertile soils and proximity to fairly developed districts and cities has attracted retirees, youths and organizations interested in farming. Lack of a developed power distribution system is the main draw-back for people wanting to settle in this area. This research intends to compare the various possible means of electrifying the farm and select the most sustainable (reliable, environmentally clean and affordable) option. Among the methods of electrification to be considered in this work are grid extension, standalone and hybrid systems. HOMER optimizer was used to attain an optimal system based on net present cost (NPC) and cost of electricity (COE) - cost indicators. The system's emission of greenhouse gases and availability of back-up source of power were environmental - cleanliness and reliability indicators respectively. Sensitivity analysis performed included: ascertaining the effect of varying inflation rate, fuel price and farm load size. From the research results obtained, it was concluded that the most sustainable means of electrifying the rural farm was by means of a hybrid system comprising of PV panels, wind turbines, battery bank, inverter and biogas generator. The average daily energy requirement for the farm in maximum demand months was 135.3 kWh/ day. The PV array was rated at 3.2 kW, wind turbines -2 by 10 kW, battery bank -26 by 12 V, biogas generator - 15 kW, inverter - 15.5 kW. The system's COE was US$ 0.12/ kWh while NPC amounted to US$ 137 300. The results of this project high-light how farmers in rural areas can generate sustainable energy, required for their daily activities such as cooking, lighting and running of farm machinery. The findings can also be useful to people in other areas faced with similar challenges.