The aviation sector, contributing to the global economic output, faces significant environmental pressure due to its 2-3% carbon emissions. To increase energy efficiency and sustainability, researchers have explored the use of thermoelectric generator systems (TEGs) to recover waste heat loss in airplane engine exhaust and convert it into electrical energy. The study found efficiencies range between 5% and 10%, with better performance with large temperature gradients. Materials like bismuth telluride show better efficiency, but higher power output may lead to fuel cuts of up to 5%. However, TEG systems face challenges such as weight and space constraints, thermals, and regulatory issues. Advanced materials could mitigate these challenges, and experimental validation with stakeholders is needed. This research lays the groundwork for further research and practical implementation of TEG systems as a transformative solution for sustainable aviation.