In some circles, 3-D printing has a reputation for being greener than manufacturing in a traditional factory. But that's not necessarily the case—at least not yet—according to a recent study.
One myth is that 3-D printing is greener because you can print something at home, or down the street, rather than shipping from a factory. But even when a product ships from thousands of miles away in China, the transportation itself is usually only a tiny fraction of the overall environmental impact, says Jeremy Faludi, a PhD student at the University of California-Berkeley who studied 3-D printing in a full life-cycle analysis.
It also isn’t necessarily true that 3-D printing saves waste, even though parts aren’t being cut out of bigger sheets of material. An inkjet 3-D printer actually ends up wasting 40% of its material, which can’t be recycled.
As 3-D printing gets easier and cheaper, it’s also likely that people will print out more things they don’t need, though Faludi predicts it won’t be a major contributor to waste.
“If it’s easy to make stuff, people will think less about it, and there will be more useless crap that gets made—unquestionably—but I don’t think it will be anywhere near as bad as paper usage and desktop printers,” Faludi says, pointing out that it still takes effort to design products, and the novelty factor of downloading models to print out will probably wear off.
Even if waste isn’t a big problem, there is one glaring environmental issue with the technology—energy usage. Keeping plastic melted takes a lot of electricity, and for a design shop that keeps 3-D printers running throughout the day, each piece printed out has a big carbon footprint. The good news is that for someone with a MakerBot at home, this isn’t likely to be as much of a problem.
It’s also possible that a shift in materials could help fix the energy challenge. At UC Berkeley, Faludi says, one professor hacked a 3D printer to use a sawdust mixture held together with adhesive instead of plastic. Unlike plastic, it wouldn’t have to be melted, and so the electricity use could be dramatically slashed. “It has the potential to be greener than any other type of manufacturing,” Faludi says, adding that he hopes to study the new material soon.
3-D printing does already have some clear advantages, including the fact that it encourages designers to make things lighter weight. “In 3-D printing, complexity is free, but mass costs money,” says Faludi, explaining that making something bigger takes more time. “So it aligns the incentive structures of the economics so they happen to match up well with environmental priorities.”
With 3-D printing, it’s suddenly possible to print complicated shapes that are lightweight but strong. Products like cars or wind turbines, which push around thousands of pounds of weight as they’re used, can save energy as parts get lighter.
And then there are the social benefits. “Honestly a lot of the advantages of 3-D printing are a little more social than environmental right now,” Faludi says. “When you’re talking about being able to print something out that just doesn’t exist where you are, there’s a huge potential for benefit in developing countries that are basically disconnected from global supply chains.”