The EU road refrigerated transport: current GHG footprint of transport refrigeration unit and projected impact of sustainable technologies

The global road transport refrigeration fleet serving the food supply chain is estimated at approximately 5.7 million vehicles. This sector is experiencing continuous growth, driven by evolving consumer habits such as the rise in e-commerce and the increasing incidence of short-distance deliveries. Sectoral emissions were estimated at approximately 50 Mt CO₂eq in 2021, with the majority attributable to diesel-powered traction systems. Approximately 20% of these emissions originate from the energy consumption of refrigeration units. At the same time, the entire road transport sector is under increasing pressure to meet stringent environmental targets. Moreover, working fluids used in vapor compression cycles are undergoing regulatory scrutiny, with a primary focus on reducing greenhouse gas (GHG) emissions, while growing attention is being paid to other potential environmental and human health impacts. This study investigates high technology-readiness-level (TRL) solutions aimed at reducing the overall environmental footprint of road transport refrigeration. The solutions considered include improved thermal insulation of refrigerated boxes, the adoption of natural refrigerants, advanced control strategies under partial load conditions, vehicle electrification, and the integration of renewable energy sources. The potential effects of implementing these technologies across the European refrigerated fleet are numerically assessed in terms of primary energy consumption, carbon-equivalent emissions, and pollutant emissions. Results indicate that the adoption of these technologies could yield reductions of up to 28% in annual primary energy consumption, up to 72% in CO₂-equivalent emissions, and over 90% in emissions of other air pollutants.