Energy, exergy and sustainability analyses of Bangladesh’s power generation sector

Ensuring sustainability in electrical power generation is a major concern in the modern world. Reducing energy depletion from power generation can reduce emissions and contribute to sustainability. Exergy analysis can be used to assess and optimize energy systems and thus can help achieve sustainability. In this analysis, energy and exergy utilization of Bangladesh’s utility sector is investigated based on data from 2007 to 2016. The overall energy efficiencies vary from 34.9% to 36.3% while the exergy efficiencies vary from 35.0% to 39.2% within this period. Thermal power plants are seen to have greater exergetic improvement potential than hydro power plants. To correlate between exergy and environmental sustainability, this study applies several exergetic parameters as sustainability indicators. It is found that the depletion number varies between 0.61 and 0.65 while the exergy sustainability index varies between 1.54 and 1.64. The relative irreversibility and lack of productivity are greater for gas operated power plants than other thermal power plants. The largest relative irreversibility is 0.90 while the largest lack of productivity is 1.72. The waste exergy ratio varies from 0.48 to 0.59 while the environmental effect factor varies from 1.35 to 1.68. Renewable power generation is found to have a higher sustainability than fossil fuel power generation. It is believed that current analysis can serve as a benchmark to help attain power generation sustainability.