Sustainable Energy Analysis of Nigerian Road Transportation Sector: Benchmarking against Global Trends

Sustainability of road transportation sector fuel exergy utilisation in Nigeria between 1990 and 2019 was examined and compared with the global trends in the same sector. Parameters used were exergy efficiency, depletion number, sustainability index and improvement potential. Petrol engines had the highest mean efficiency of 13.05% and heavy duty vehicles the lowest of 8.57%. Their respective mean depletion numbers were 0.8695 and 0.9143, while their mean sustainability index values were 1.1501 and 1.0937 respectively. However, petrol engines had the highest mean improvement potential of 2.07×1011 MJ and cars had the lowest value of 1.86×1010 MJ. When benchmarked against global values, petrol engines still had the highest mean potential difference value of 5.93×1010 MJ while cars had the lowest value of 6.02×109 MJ. Improvement potential values were largely influenced by exergy utilisation rates, the influence of which outweighed that of exergy efficiencies, of the different carriers.