Near-Infrared Reflective Greenhouse Covering: A Novel Strategy for Electricity-Free Cooling

Abstract

Traditional cooling strategies for greenhouses commonly result in significant electricity consumption and a substantial release of carbon dioxide emissions. Considering the industrial fabrication process for the greenhouse covering film and the thermal management theory, we developed a composite greenhouse covering film that incorporates titanium dioxide into polyethylene to achieve near-infrared reflection. The film demonstrates an impressive near-infrared reflectance of 54.4% within the wavelength range of 780–2500 nm. A tunnel-type greenhouse demo comparative test results show that the composite film can effectively decrease the average temperature inside the greenhouse by 6.7 °C in comparison to the pure polyethylene film. The reduction implies a significant annual saving in cooling electricity at the national level of 2151912.3 MW h, along with an annual CO₂ emission reduction by 1250261.1 tons.