Life cycle assessment of lignite-fueled ultra-supercritical coal-fired power plant with evaluation of solar energy integration

Coal-fired power plants significantly contribute to global greenhouse gas emissions and air pollution. This study performs a comprehensive Life Cycle Assessment (LCA) of an ultra-supercritical coal-fired power plant (USC CFPP) in Pakistan, focusing on the environmental impacts of using local Thar lignite and imported Indonesian lignite. Key impact categories analyzed include Climate Change Potential, Human Toxicity Potential, Particulate Matter Formation, and Terrestrial Acidification. Results indicate that the Climate Change Potential of local coal is nearly double that of imported coal due to its higher sulfur content and lower heating value. Conversely, the transportation of imported coal contributes significantly to Human Toxicity Potential from particulate matter release. Blending local and imported coal demonstrates substantial environmental benefits, reducing Climate Change Potential by 18.43%, Terrestrial Acidification by 61.51%, Photochemical Oxidant Formation by 36.86%, Human Toxicity Potential by 36.86%, and Particulate Matter Formation by 56.51%. Additionally, integrating solar energy with the USC CFPP enhances plant efficiency by 0.71% to 0.97%, offering a hybrid approach to lower emissions and improve resource efficiency. The Life Cycle Savings (LCS) analysis shows that high inflation rates, discount rates, and capital costs can reduce LCS. Sensitivity analysis further reveals that high capital costs and discount rates can extend the payback period. These findings emphasise the potential of solar-integrated USC CFPPs for reducing environmental impacts and improving economic efficiency, representing a sustainable approach to coal-based power generation.