Solar Reflective Car Shells: Simple as Black and White?

Posted on the 08 November 2011 by 2ndgreenrevolution @2ndgreenrev

You’ve heard the sad tales about dogs (and yes, even children) trapped in hot cars as there owners go to do some shopping. Anyone who’s opened up a car door after it’s been sitting in the summer sun for even a few minutes knows how hot they can get. Cars painted black are the worst. So what if you had a lighter colored car? Would such a simple change have an effect on the heat that builds up inside on a sunny day? Would there be some kind of positive impact on your budget or even on the environment? Scientists at Lawrence Berkley National Lab recently released a study they conducted on the efficacy of solar reflective paints on cars; basically, lighter colored cars. They found that up to 60% of the total sunlight can be reflected by having the right color paint.  From their website:

A light-colored or cool-colored car shell reflects more sunlight than a traditional dark car shell. This cools the cabin air and reduces the need for air conditioning. A recent study found that after parking in the sun for an hour, a silver Honda Civic (shell SR 0.57) had a cabin air temperature about 5-6°C (9-11°F) lower than an otherwise identical black car (shell SR 0.05). Modeling indicates that substituting a silver (or white) shell for a black shell would allow the specification of a 13% smaller (lower capacity) air conditioner, improving fuel economy.
Cool cars can benefit drivers, cities, and the planet.

  • Fuel savings. Substituting a cool shell for a conventional black shell permits the use of a smaller air conditioner, improving fuel economy by 1% (for a cool colored shell with 35% solar reflectance) to 2% (for a white or silver shell with 60% solar reflectance).
  • Better air quality. Specifying a smaller air conditioner reduces tailpipe emissions of nitrogen oxides, carbon monoxide, and hydrocarbons.
  • Slowed climate change. Specifying a smaller air conditioner reduces tailpipe emissions of carbon dioxide. Cool car shells also reduce the flow of heat from vehicle to atmosphere.
Take a look at the image in this post to see how high in the triple digits the inside of Eric’s Honda got last summer.

[Image by 2nd Green Revolution]