Pre-fabricated, environmentally friendly and energy self-sufficient single-family house in Kenya

Abstract

This work provides a comprehensive approach for electrification of rural areas of Kenya through taking into account both energy demand and supply sides. Toward this, a pre-fabricated composite building is assessed by defining two different levels of energy needs and calculating annual cooling and heating energy demands to keep the occupants within the comfort temperature range. Consequently, four passive cooling techniques (shading, natural ventilation, cool painting and increased thickness of interior gypsum plaster) are applied to decrease the cooling energy demand. Afterwards, a stand-alone photovoltaic (SAPV) system is designed through sizing of the main components as well as determining the optimum tilt angle and azimuth for the PV array. Finally, four PV technologies (monocrystalline silicon (mono-Si), polycrystalline silicon (poly-Si), cadmium telluride (CdTe) and copper indium selenide (CIS)) were assessed for the designed SAPV system and compared in terms of environmental impact and cost and CIS demonstrated the best performance in all criteria. The results highlight a reduction of about 84% in cooling energy demand through combining all passive cooling techniques originating a house displaying passive behavior. Moreover, the SAPV system proves to be a feasible solution with significant lower cost and greenhouse gas (GHG) emissions in comparison with alternative solutions. The results also outline the importance of the loss of load probability (LLP) in designing SAPV systems indicating a sudden increase in required power of array for LLPs less than 2%.