Techno-economic assessment of hybrid solar energy for residential application in Mozambique

Abstract: I Mozambique many areas are not connected to the national grid because of financial reasons. The renewable energy technology is adequate as a solution for this problem because it would avoid the environmental impact and the increase of air pollution. Hence, the techno-economic assessment of hybrid solar energy was performed for residential application considering a small community of 50 households, each consuming about 1 kWhe and 3 kWhth per day. HOMER, the energy modeling software for hybrid renewable energy system (HRES), was used for reaching this objective. The techno economic study of a domestic hot water system was performed using RETscreen as HOMER could not be used since it does not model solar collectors. To model the PV system using HOMER software, the load and the solar resource were assessed, considering the economics, system components, optimization and sensitivity analysis, which enabled the determination of the optimal system configuration and evaluation of how the system is sensitive with different values of primary load, global solar, interest rate and project lifetime. As a result, the maximum power of the collector was found to be 1.93 kW, hot water storage volume of 138.1 l and 3.05 m2  flat plate collectors. The pre-tax IRR - assets is of 14.5 %, the simple payback period is of 8.6 years to return the investment and the 7.4 years of equity payback. The PV system with the optimal system configuration consisting of a 0.3 kW PV array, 4 HI-Fase 200 Ah batteries and a 0.5 kW converter. The initial capital for PV system is of $3.945, operating cost of $82 per year, levelized COE of $1.604/kWh and the total NPC is $4.591. The sensitivity analysis for PV system has shown that the best estimate scenario with a primary load of 1 kWh/d, global solar of 4.5 kWh/m2/d, interest rate of 11 % and 25 years project lifetime is 0.4 kW PV, 4 HI-Fase 200 Ah batteries and 0.5 kW converter.