Passive radiative cooling and cool roofs offer energy efficiency

Advanced passive radiative cooling paints and cool roof technologies are emerging as significant alternatives to traditional air conditioning. These materials work by reflecting up to 95 percent of incoming solar energy and emitting infrared thermal radiation at specific wavelengths that pass through the atmosphere, allowing surfaces to remain cooler than the ambient air without consuming electricity.

In California, the adoption of cool roofs is being used to mitigate the urban heat island effect and reduce energy consumption. Cities such as Los Angeles and Pasadena have implemented requirements for cool roofs in new residential construction and certain nonresidential buildings. Implementing these solutions across populous areas could potentially reduce heat wave exposure by 35 million people annually while alleviating pressure on electrical grids and reducing greenhouse gas emissions.