Energetic, exergetic, and environmental evaluation of railway transportation by diesel and electric locomotives

Abstract

It is critical to reveal the amount of energy and exergy-losses of a system along with environmental issues. This article aims to carry out energy, exergy, and environmental analyses in rail freight trains hauled by diesel and electric locomotives. This study is an important tool for policymakers and energy-planners to gain insight into the performance of the railway-sector, which is an important transportation way in Turkey. It should be a challenge for society and governmental institutions to decrease the losses and to improve the overall performance due to severe energy-problems. The overall energy-efficiency of diesel trains was calculated to be 29.1% as that of exergy-efficiency was 27.2% between 2005 and 2018. In the case of electric-trains, these became 43.4% for 2005-2018. The average overall energy and exergy efficiencies of the railway sector were calculated to be 30.94% and 29.3%, respectively. The results indicate that there is a significant improvement potential in the railway sector. The average carbon emissions of diesel and electric trains are 1.372 kgCO(2)/kWh and 1.346 kgCO(2)/kWh, respectively. The carbon emission of the electric trains per annual useful energy (kg-CO2/kWh) is comparatively high due to the electricity generation methods in the country.