Evaluation of biofuel production integrated with existing CHP plants and the impacts on production planning of the system – A case study

•Regional combined heat and power (CHP) plants are integrated with bioethanol supply.•The influence of polygeneration on production planning of CHP plant is investigated.•Three extreme cases related to transportation system are developed and investigated.•Integration and power supply from rooftop panels affect production planning of system.•Use of hybrid cars is the optimal approach concerning fuel use, cost, CO2 emissions.