An effective sizing and sensitivity analysis of a hybrid renewable energy system for household, multi-media and rural healthcare centres power supply: A case study of Kaele, Cameroon

Abstract

The vast majority of rural Africans lack access to clean, reliable, and sustainable electrical energy. This has deprived rural inhabitants of the opportunity to receive advanced healthcare delivery and modern education. In this study, an off-grid hybrid system composed of solar panels, wind turbines, battery banks and diesel-powered generators has been designed to fulfil the electrical loads requirements of a household, a multi-media and healthcare centres situated at Kaele, Cameroon. Initially, the wind and solar potential of Kaele were investigated and four meta-heuristics algorithms, namely, the colliding bodies’ optimization, charged system search, teaching-learning-based optimization (TLBO) and the water evaporation optimization algorithms are applied to the hybrid system and the results are compared with regards to the system net present cost (NPC). Thereafter, three off-grid hybrid systems: PV/Wind/Battery/Diesel, PV/Battery/Diesel, and Wind/Battery/Diesel were compared based on a techno-economic and environmental analysis. The results showed that, the mean yearly wind speed and solar radiation of Kaele are 6.7 m/s and 7.20 kWh/m2/day, respectively. Comparing the search power of the aforementioned algorithms on the sizing problem, it has been found that the TLBO algorithm produces better results than the other algorithms. The results also showed that, the PV/Wind/Battery/Diesel configuration is the cost-effective option for supplying the household, multi-media and healthcare centres. The obtained optimal combination and the NPC of the PV/Wind/Battery/Diesel system are as follows: For household, the most appropriate configuration combines 9 solar panels, 2 wind turbines, 33 battery banks, 1 diesel generator and the obtained NPC corresponds to 26111.2$; for the multi-media centre, 52 solar panels, 2 wind turbines, 96 battery banks and 1 diesel generator which resulted to a NPC of 55511.2$; and for the healthcare centre, the ideal configuration consists of 13 solar panels, 1 wind turbine, 13 battery banks and 1 diesel generator with a NPC of 19008.7$. The cost of energy of the optimal system was found to be 0.2419$/kWh, 0.2195$/kWh and 0.2158$/kWh for household, multi-media and healthcare establishments, respectively. The results also revealed that for household and healthcare centre the obtained break-even grid extension distance was 0.443 km and 1.23 km, respectively for the PV/Wind/Battery/Diesel system. Since this separation is smaller than the nearest grid extension distance of 5 km, it is concluded that the proposed hybrid energy system is suitable for powering the household, multi-media and healthcare centres in Kaele, Cameroon. Finally, a sensitivity analysis of each relevant component cost, resources availability and microeconomic variables of the PV/Wind/Battery/Diesel system is carried out to acquire a more suitable configuration.