When you think of “cool car,” you probably don’t think of a practical family sedan. But Nissanthe Japanese automaker behind these SUV models, is trying to be – literally – one of the coolest cars on the market.
Nissan is testing a heat-reflective white paint that can cool the outside temperature of its cars by as much as 22 degrees Fahrenheit and the inside temperature by 9 degrees Fahrenheit, the automaker said. The goal is to avoid the inevitable heat buildup in Nissan vehicles that normally accompanies parking a car in the hot sun and give users the option to reduce air conditioning use. This is part of an initiative by the company – and the entire auto industry – to increase efficiency of cars amidst elevated Sustainability concerns in a warming climate.
“My dream is to build cooler cars without consuming energy,” said Susumu Miura, senior manager of the Advanced Materials and Processing Laboratory at the Nissan Research Center, in a Press release“This is especially important in the age of electric vehicles, as the strain of running air conditioning in summer can have a significant impact on the state of charge.”
Nissan unveiled the paint, which is six times thicker than typical car paint, at the Tokyo International Air Terminal in Haneda in November 2023 for a 12-month test. In collaboration with energy technology company Radi-Cool, the company has applied its cooling paint to airport service vehicles. Miura hopes Nissan will also extend the paint to commercial vehicles.
The technology has become increasingly attractive in view of the efforts to climate-friendly vehicles. Toyota is also Experimenting with color that has the potential to cool cabin temperatures. In 2021, a team of engineers from Purdue University developed the the whitest white in the world Color that can reflect over 98% of sunlight. A year later, the team developed a thinner version the paint that can be used to coat airplanes, cars and space shuttles.
The key to the effectiveness of Nissan’s cooling paint are two particles: one that reflects near-infrared rays that normally cause normal paint to absorb heat, and another that generates electromagnetic waves to dissipate the heat.
“Basically, it combines light of different wavelengths so that the light is reflected at all sorts of angles at different wavelengths,” said Shu Yang, a professor of materials science and engineering at the University of Pennsylvania. Assets.
Yang compared the paint to sunscreen, which absorbs and reflects UV rays from the skin. Even the materials in the paint have similarities to sunscreen, such as titanium oxide, the basic compound in many cooling technologies that reflect heat. Although the paint appears white, Yang said that is not due to a pigment added to the paint, but rather to the structural particles from which the paint itself is made.
A bright future lies ahead of us
Although more automakers are adopting reflective white paint as a cooling solution, there are many unanswered questions about how the technology can be improved in the future. Environmentally conscious Nissan customers, for example, can save themselves the trouble of giving their cool cars a colorful coat of paint, Yang said. The cooling paint will remain white as materials scientists continue to determine the optimal particle size for reflecting light and heat. The end goal will likely be to develop an effective, translucent paint that can be used to coat colorful car pigments, she said.
The problem is simply figuring out how to do that. Even beyond the development of cooling colors, there are still too many scientific unknowns about how and why certain colors reflect and absorb heat. While the general scientific rule is that light colors reflect heat and dark colors absorb it, there are still anomalies, such as the dark purple eggplant.
“If you touch the skin of the eggplant, it’s actually cool,” she said. “There are a lot of questions: Why and what happened?”
However, materials scientists warn that even technological discoveries and improvements in these technologies have only limited benefits in combating climate change. The compounds such as barium sulfate must be mined and extracted, which cause higher CO2 emissions.
Jeremy Munday, a professor of electrical and computer engineering at the University of California, Davis, said painting cars reflective white paint is essentially just a drop in the bucket when it comes to combating the effects of greenhouse gases pumped into and trapped in the atmosphere.
“This is definitely not a long-term solution to the climate problem,” Munday said. said the New York Times“This is something you can do in the short term to mitigate worse problems while you try to get everything under control.”