Case Study on Cost Saving and GHG Emission Reduction From Coupling Air Source Heat Pump With Photovoltaic/Thermal Collector

TRNSYS simulation software was used to modify a validated Air Source Heat Pump (ASHP) model in an Archetype Sustainable House (ASH) in Toronto. In this model, a Building Integrated Photovoltaic-Thermal Collector (BIPV/T) was coupled with ASHP. The PV/T system arrangement was considered as a part of the south-oriented roof of the house. The warm air generated in the BIPV/T collector was considered the source of the heat pump for heat production. The coupling of BIPV/T and ASHP enables a highly efficient heating system in harsh winter conditions. The developed TRNSYS model of the house along with integrated PV/T system with ASHP was simulated for the whole year to predict the hourly outlet air temperature, thermal energy and electricity obtained from the PV/T array. The results from the simulation were used to estimate the saving in energy and cost as well as to predict the electricity related GHG emission reduction potential from the PV panels. Monthly greenhouse gas (GHG) emission credit from PV production based on hourly GHG emission factor was obtained; the results showed that annual GHG emission due to electricity demand by the ASHP was reduced by 225 kg CO₂ (19.3%) when the heat pump was integrated with the PV/T array. Also, in this study, the annual electricity cost credit from PV production based on Time-of-Use (TOU) and the reduction in electricity cost of the heat pump when connected with PV/T systems was calculated and compared with the cost of working the heat pump alone. The results show that there is a saving of $500 in annual electricity bills and GHG emission credit of 862.6 kg CO₂ from renewable electricity generation.