Overview of energy harvesting and emission reduction technologies in hybrid electric vehicles

Hybrid electric vehicles (HEVs) have been developed extensively thanks to the inherent merits of both internal combustion engine vehicles (ICEVs) and battery electric vehicles (BEVs). In HEVs, batteries and electric motors are introduced to help internal combustion engines improve fuel efficiency and reduce greenhouse gas (GHG) emissions. Accordingly, HEVs provide opportunities for energy harvesting methods that are suitable for both ICEVs and BEVs. With these energy harvesting methods, more energy can be harvested from HEVs and lower GHG emissions can be achieved. Therefore, energy harvesting methods are investigated in this critical overview and discussed from four perspectives, namely waste heat recovery from exhaust gas, mechanical energy recovery from braking, vibration and/or shock, alternative fuels and renewable energy integration, with emphasis on thermoelectric generators, the organic Rankine cycle, regenerative shock absorbers, regenerative braking and solar roofs. Specifically, the working principles, distinct features, current research, and challenges of various energy harvesting methods in HEVs are discussed. In the conclusion, recommendations for future research are provided. This study provides a comprehensive overview of energy harvesting and emission reduction technologies in HEVs.

Automated summary

Hybrid electric vehicles (HEVs) have been developed by combining the advantages of internal combustion engine vehicles (ICEVs) and battery electric vehicles (BEVs). They utilize batteries and electric motors to improve fuel efficiency, reduce emissions, and offer various energy harvesting methods. Research discusses a range of energy harvesting methods from waste heat recovery to mechanical energy recovery, alternative fuels, and renewable energy integration, along with their challenges.