Here is a summary of the document in 3 sentences or less: [SUMMARY] The document discusses a TurBUS project that aims to recover residual energy from bus exhaust gases using a turbo generator system. It analyzes different methods of recovering exhaust energy and simulates a internal combustion engine with a turbo generator, finding it can reduce fuel consumption by 2.2% on average and increase power output. The project would pay for itself within 2.5 years for a fleet of 100 buses.