Optimal Design of a PV System for the Model JUA House: A Typical Green African House

Abstract

In the wake of the current global energy crisis, the African continent is lagging behind with tremendous challenges in energy security and energy efficient buildings. The continent needs a wakeup call and a shift to a new paradigm of smart energy use (Solar Decathlon, 2017). Renewable energy powered and self-sustainable buildings should be part of Africa’s new construction. In the scope of the Solar Decathlon Africa, a model of such green and selfsustainable building is under construction by PAUWES students, Team Jua Jamii. This study presents an intuitive and numerical methodology to perform the sizing and optimization of the model Jua House PV system. The purpose is to find a suitable configuration, among a set of system components and technologies, and solar decathlon rules, that meets the load requirement at the lowest cost. A 27.615 kWh/day PV load of the Jua House was split between day time load of 9.460 kWh/day off grid assembly and night time load of 18.178 kWh/day grid tied assembly. The system was sized based on the KEG-Method mathematical model and then programmed on MATLAB Simulink environment to simulate the behavior, and numerically find an optimal combination of PV array and battery in terms of the techno economic parameters: LLP, TEL, SOCmin and LCOE. The results for off grid assembly (day time load) optimization showed that the optimum configuration obtained using 17 of 270 Watt Almaden Poly SAP60T PV module, 4 of 220Ah 12V Victron Energy Gel battery, and one Infinisolar V-5K-48 Inverter technology provided for the desired system reliability (LLP = 0), with the lowest LCOE of 0.727 $/kWh (413.4179 FCFA/kWh) and a SOCmin of 37.2%. The results for grid tied assembly (night time load) optimization showed that the optimum configuration obtained using 21 of 250 Watts Panasonic HIT PV module, and one Infinisolar V-5K-48 Inverter technology provided for the desirable system reliability (LLP = 0), with the lowest LCOE of 0.0802$/kWh and energy to the grid of 5296kWh. Consequently, the entire system contains 9.840 kW PV Capacity, an emergency storage of 880Ah at 12V, and a 10kW inverter capacity. All at a total cost of $21406.5, which is $11541.7 lower than the non-optimized system. System optimization has reduced the total cost of the Jua House PV system by 35% and insured the desired system reliability, LLP of 0