The new type of paint could potentially lower interior temperatures, which could reduce the energy consumption of EVs. The paint could be produced, but on a special order basis.
Nissan is testing a paint that could lower the temperature inside cars and cut energy use for air conditioning.
Nissan says the paint incorporates a “metamaterial,” a composite material containing two types of light-responsive particles: One particle reflects sunlight's near-infrared light, inducing molecular-level vibrations that would normally generate heat in the paint resin; the other particle redirects energy away from the surface via electromagnetic waves.
Nissan says the two particles work together to reduce heat transfer to the paint. When parked side-by-side in the sun, cars with the cooling paint experienced a 21.6°F drop in exterior temperature and a 9°F drop in interior temperature, the company said.
Nissan tests cool paint technology
Nissan says the paint's ability to keep the surface cool is particularly useful when a car is parked in the sun for long periods of time, requiring less use of the air conditioning to cool the interior, which reduces strain on the engine in internal combustion vehicles and also reduces energy draw from the battery pack in EVs.
This type of cooling paint is not new, but is typically only used on buildings, Nissan explained in a statement. The paint is often very thick, requires a paint roller to apply, and doesn't have a top clear coat like automotive paints, leaving a chalky residue when touched.
Nissan began developing its automotive paint in 2021, testing more than 100 samples. The current version, which Nissan began testing at Tokyo's Haneda airport in Japan in November 2023, is 120 microns thick, about six times thicker than typical automotive paint. It can still be applied with a spray gun and meets Nissan's standards for chipping, scratching, resistance to salt and chemical damage, and repairability.
Nissan tests cool paint technology
Nissan plans to continue developing thinner coatings with an eye toward mass-produced vehicles, but the company indicated they would more likely be custom-made for fleets that spend long periods outdoors.
Not only does constant air conditioning increase energy demands, but EV batteries also degrade faster in hot weather. But they don't suddenly fail and leave people stranded. If you have to leave your car in the heat, measures like parking in the shade and keeping the battery half-charged can also help keep the battery pack safe and cool in high temperatures.
