Towards decarbonization in transportation: scalable transparent radiative cooling for enhanced vehicle energy efficiency

Abstract

Vehicles exposed to sunlight experience rapid heating due to low thermal mass and confined space, leading to excessive HVAC energy consumption. Transparent radiative cooling (TRC) provides a passive pathway for heat mitigation, but existing TRC technologies face limitations in optical clarity, durability, and real-world validation. Here, we present a scalable transparent radiative cooling (STRC) film for vehicle windows, achieving >70% visible transmittance, strong mid-infrared emittance, and high solar reflectance. Full-scale field tests across various regions and vehicle types show substantial cabin temperature reductions of up to 6.1 °C and energy savings exceeding 20%, with a minimal winter heating penalty of 0.3%. Seasonal analysis and U.S. fleet-scale modeling further project an annual CO₂ reduction of 25.4 megatons—equivalent to removing 5 million cars from the road. STRC thus provides a practical, durable, and zero-energy cooling solution for sustainable and decarbonized transportation.