Hybridization of energy systems for air conditioning application in an educational building

Abstract

This study reports the hybridization of energy systems for an air conditioning (AC) application in an educational building, using the Faculty of Engineering Lecture Theaters at Rivers State University, Port Harcourt, Nigeria as case study. It includes conceptual design of a hybrid energy system of thermoelectric and solar energy, analysis of cooling load to select suitable air conditioning system for the building using Carrier’s Hourly Analysis Program (HAP) software, analysis of the required energy to drive the air conditioning system, and techno-economic analysis of the system. The analysis carried out shows that a total of 4 packaged rooftop air conditioners each of 10.6kW (30,000 Btu/h) capacity would be required to handle the building’s cooling load of 38.28kW, and would require 344.5kWh of energy per day, out of which 249kWh/day would be generated from the thermoelectric generator (TEG) modules, and the remaining 95.5kWh/day would be generated from the photovoltaic (PV) modules. The 249kWh/day of energy required from the thermoelectric energy system would require a total of 1600 TEG modules of 26W each, and the 95.5kWh/day of energy required from the solar system would require a total of 65 PV modules of 330W each. The energy generated would be stored in a 679kWh capacity battery storage system which contains 72 batteries of 48V and 200Ah capacity each, which are wired into 3 parallel strings, which would supply the AC system. The techno-economic analysis carried out shows that the system designed can be implemented at a cost of ₦98,558,000, with a payback period of 9years, and would mitigate 72,050.5kg of CO2 emissions annually.