Solar PV Coupled with Passive and Active Efficient Cooling Systems for a Smart African Solar House

Abstract

Africa is experiencing more and more serious challenges of energy crisis, ozone depletion and global warming. Space cooling is rapidly growing in both residential and commercial buildings accounting for about 18.5% of the total electricity used and the global energy consumption for cooling in buildings is expected to increase up to 35% in 2050, raising the CO2 emissions due to the construction of new power plants. In Africa, more than 600 million people live without access to electricity and the poor economic development poses a serious hindrance to access to cooling. However, Africa is endowed with a huge potential for solar cooling due to the near coincidence of peak cooling loads with the available solar power. The design of a combined passive and active solar cooling solution was done in the context of Solar Decathlon Africa competition to provide a cost effective and energy efficient cooling solution for buildings in Africa. An of the energy analysis of the Jua house (solar house) was performed using DesignBuilder Software to evaluate the performance of proposed passive cooling techniques. The results revealed a 20% reduction from 2195kWh to 1758kWh in cooling energy per month. The optimal design of a compression cooling system with COP of 3.88 and electrical power requirement of 3.14kW and that of a Peltier cooling system with COP of 0.36 and electrical power consumption of 33.61kW, shows that compression system is the most energy efficient option for electrical cooling in buildings. The results of Solar PV sizing shows that a total of 272 modules of 250W PV panels are required for Peltier system compared to 30 modules of 250W PV panels for vapor compression system. Finally, A cost comparative study proves that air conditioning systems is cheaper option with total system cost of $13330 compared to $67120 for Peltier cooling system. However, rigorous actions from public authority need to be taken to curb the potentially huge growth in cooling demand and promote energy efficiency in buildings in Africa