Exergy-Based analysis of CO2e reduction by campus solar energy installation for sustainability improvement

Abstract

Sustainability studies aiming to reduce CO2e emissions is increasing gradually. Generally energy-based approaches is being used in these studies. In this paper, the carbon footprint calculations of energy-consuming systems in the OSTIM Technical University building is examined, focusing on the use of solar energy for emission reduction. An Exergy-based approach, generally ignored in CO2e calculations, is adopted. The carbon emissions calculation is carried out according to the ISO14064 by monitoring the University’s energy consumption. In order to reduce CO2e, use of solar energy PV panels for the University building is evaluated. Calculations showed that intended PV panels could meet 16% of the annual electricity demand, leading to an 18% reduction in CO2e emissions compared to grid reliance. For Exergy analysis, general electricity generation sources (fossil fuel, renewable, etc.) are considered in obtaining the CO2e caused by using grid electricity. It is concluded that using electricity generated from PV panels instead of grid electricity resulted in less exergy destruction and approximately 61% low in carbon emissions. The planned PV panel installation’s payback period calculated as 5.1 years. The obtained results suggest that calculating CO2e emissions using the Exergy method provides a more realistic view, due to not only considering consumption but also taking into account energy generation, transmission, and distribution lines.