Quantifying the GHG Reduction versus Battery Size in Diesel Buses with Electrified HVAC

Major North American transit operators are targeting zero-emission bus fleets over the next 10-20 years, but a short-term emissions-reduction solution is required for existing operational fleets. In this work, a detailed system simulation is used to determine the emissions-reduction potential of electrifying only the heating, ventilation, and air-conditioning loads in diesel-based transit buses. The electrical power is provided by a rechargeable Lithium-ion battery. The annual average emissions reduction potential of electrified HVAC in transit buses is quantified versus the battery size and varying environmental conditions. Candidate deployment scenarios are explored for three different cities in North America, and it is found that the emissions reduction per bus is between 7.8-17.1t/year for battery packs between 50-100 kWh.