Nissan develops new ‘cool paint’ for automobiles

In a significant stride towards improving vehicle efficiency and comfort, Nissan Motor Co., Ltd. has announced the development of an innovative “cooling paint” that has the potential to lower the interior temperature of vehicles by up to 5°C. This cutting-edge technology is designed to reduce the reliance on air conditioning, thereby enhancing fuel efficiency and extending the range of electric vehicles (EVs).

Revolutionizing Vehicle Comfort with Metamaterials

The “cooling paint” technology was developed in collaboration with Radi-Cool, a company renowned for its expertise in radiative cooling products. At the heart of this breakthrough is the use of metamaterials—synthetic composites with unique properties not found in natural substances.

These materials are engineered to reflect sunlight, specifically near-infrared rays that are responsible for heating vehicle surfaces, while also radiating thermal energy away from the car.

The paint’s ability to lower vehicle temperatures stems from two types of micro-structured particles embedded within the coating. The first particle type reflects near-infrared light, reducing the heat generated by the sun’s rays.

The second type emits electromagnetic waves that counteract solar energy, effectively dispersing heat away from the vehicle’s surface and into the atmosphere.

Promising Results from Rigorous Testing

Nissan has conducted extensive testing of this new paint at Tokyo’s Haneda Airport, beginning in January 2023. The large, open runway provided an ideal environment to evaluate the paint’s performance under extreme temperature conditions.

The results have been remarkable: vehicles treated with Nissan’s cooling paint exhibited a temperature reduction of up to 12°C on exterior surfaces and up to 5°C in the driver’s seat headspace compared to vehicles coated with conventional automotive paint.

The implications of these findings are significant. By reducing the need for air conditioning, the cooling paint could lead to improved fuel efficiency and lower electricity consumption in EVs. This is particularly important as the automotive industry continues to pursue decarbonization and more sustainable transportation solutions.

Challenges and Future Applications

While the technology shows immense promise, there are challenges to overcome before it can be widely adopted. One of the primary hurdles is the thickness of the paint film. Currently, the self-radiative cooling paint is six times thicker than standard automotive paint, which complicates mass production.

Nissan is actively working to reduce the paint’s thickness while maintaining its cooling performance, with the goal of making it commercially viable.

For now, Nissan is considering the use of this paint on commercial vehicles, such as trucks and ambulances, which are often exposed to intense sunlight during operation. These vehicles would benefit greatly from the temperature-lowering effects of the paint, improving driver comfort and operational efficiency.