With the Earth’s atmosphere already well past stable levels of CO2 , it’s vital that we ensure that all new technologies are as efficient and beneficial to the environment as possible so that we don’t commit the same mistakes as the generation before us. Rather than take every new device as a blessing – regardless of potentially negative impacts on the health of communities, on the environment, or on the economies of other nations – we have to do our best to innovate altruistically from the start. At Responding to Climate Change (RCC), Nilima Choudhury has published a great post that addresses the environmental sustainability of 3DP/additive manufacturing, titled “How green is 3D printing?”
So, how green is it?
The post takes data from a variety of sources to feel out the potential positive and negative consequences that 3D printing has — and will have — on the environment, as the technology becomes more widespread (citing estimates by the U.S. Department of Energy that AM could be a $5 billion industry by 2020). Dr Martin Baumers, a professor at the University of Nottingham’s EPSRC Centre of Innovative Manufacturing in Additive Manufacturing, for instance, told the blog what many that are familiar with 3D printing already know: compared to subtractive manufacturing, additive manufacturing uses a lot less material and, therefore, creates a lot less wasted byproduct. While many have used this fact alone to propose the sustainability of 3D printing, they may overlook other key factors.
The ATKINS project, a research endeavor conducted by Loughborough University and industry experts to determine 3D printing’s carbon footprint, discovered that 3D printing may not always be so green when it comes to energy use. Funded with £2.7m from the UK’s Technology Strategy Board, Nottingham’s Professor Richard Hague, et al. teamed up with AM research firm Econolyst to measure the energy usage of 3D printing compared to that of a huge host of traditional manufacturing techniques. What they found is that, when it comes to the actual printing of a metal object using Selective Laser Melting, the amount of energy used is not too different from machining a metal object, with Professor Hague saying, “We started off thinking additive manufacturing was going to be good at the production stage, you’d use less energy at the production stage. It turns out it’s about comparable [to machining] at the production stage. The real benefit you get is at the material production stage because you use less material during the in-use phase.”
In an interview with RCC, Nick Owen, director of manufacturing firm 3D Print UK, explained that, because 3D printing produces fewer items in the same span of time as injection-moulding, it can be much less efficient:
Because you’re using heat processes or powerful lights to cure resins they’re very energy hungry so your actual energy usage per item is very high. If you compare that to mass production where an injection mould is pumping out 1,000 things an hour, our machine is probably pumping out 100 things a day using the same amount of electricity.
Owen also pointed out that, in the case of filament recyclers, like the Filabot, the quality of plastic that may be reused degrades over time. This makes recycled plastic more prone to breaking with each re-use.
RCC, however, explains another benefit that 3D printing enthusiasts are already aware of and this benefit may be what ultimately makes the tech more green than traditional manufacturing methods in certain regards. Because 3D printing allows users to construct more complex geometries, it is possible to produce objects with lighter, more streamlined geometries. In the case of the transportation industry, as the ATKINS project discovered, this can save huge amounts of fuel. By 3D-printing aerospace components, for instance, Econolyst’s Dr. Phil Reeves told The Engineer that manufacturers could reduce the carbon footprint of a vehicle by “‘three to four orders of magnitude more’ than the amount of CO2 emitted to make them.” Reeves explained it in this way, “There’s a figure that’s quoted within the industry that if you could save 100 kilograms in aerospace you save $2.5m of fuel.”
The way I see it is that, like many potentially green technologies that could do much to reduce CO2 emissions, 3D printing still has some negative environmental impacts at the current moment. Just as solar panels are made from some toxic elements and the batteries of electric cars, also made from toxic elements, still harness power generated from coal, natural gas, and nuclear power plants when they need a charge. What this means is that, we’re still not there, yet, in terms of environmental sustainability. After we’ve perfected 3D-printed solar cells (a link obtained from RCC) or miniature windmills, it will become easier to reduce 3D-printing’s environmental impact even further. And, because most nations (especially the United States) are still stuck to an unsustainable national power grid, no source of energy – and, so, no manufacturing method – will be green until the entire power grid is green. This means more wind farms and less fracking.
So, 3D printing is a step in the right direction, but there’s still more to be done. At least, this time around, as a species, we’re on the lookout for what sorts of consequences our present actions have on the future. My only question is if we’ve started to learn this lesson in time.
Feature Image Source: Thingiverse user RobMartin701