Abstract
In this study, two techniques were used to reduce electricity demand in the building. In the first technique, PCM of RT18 was injected with 5 cm thickness into the walls and roof. This material reduced the energy exchanged from the building and led to 24.76% less electricity usage by the chiller to adjust the building temperature at 25 °C and 28 °C in occupancy and non-occupancy hours. This PCM led to electricity saving by 19,945 kWh/year. In the next step, photovoltaic cells were added to the PCM-filled roof. The PV installed in the roof generated electricity in the range of 4200–9500 kWh. When installed on a PCM-equipped roof, the photovoltaic cells reduced the intensity of the radiation and, as a result, allowed less thermal energy to enter the building through the roof. Consequently, electricity demand dropped by 5.5%. Eventually, the installation of photovoltaic cells resulted in electricity saving by 84,351 kWh/year due to the electricity generation and 3294 kWh/year owing to a decrease in radiation intensity over the roof.
•Two techniques of adding PCM and mounting PV on roof were used to reduce electricity demand.•PCM reduced the energy exchanged from the building and led to 24.76% less electricity usage.•PCM led to electricity saving by 19,945 kWh/year.•Mounting PV resulted in electricity saving by 84,351 kWh/year due to the electricity generation.