3D printers are the most powerful machines ever invented because they can make finished products—with all their parts—fully assembled. They may also be the greenest machines ever built.

Driven by a digital blueprint, these printers build layer upon layer of fused ceramics, glass, sand, plastic, metal, or other materials. In contrast, traditional manufacturing depends on assembly lines, lots of low-cost labor and mass production. Today, much of that manufacturing takes place in far-off lands, and products must be shipped in long and complex supply chains that extend around the world. All of this has a large energy footprint.

3D printing (also known as additive manufacturing) eliminates assembly lines because a single machine can make an entire part or product, and one worker can run an entire room full of 3D printers. 3D printing allows parts to be made near the point of need. Regional manufacturing, distributed all over the world, shortens supply chains and reduces shipping and warehousing.

In addition, it is no more energy-expensive, per part, to 3D print one part vs. a million parts, to customize every part instead of making them all the same, and to make highly complex parts. Using traditional methods, making complex, one-off, and customized parts is an energy hog.

Reducing Energy Footprints

The benefits of additive manufacturing make it more environmentally friendly than traditional manufacturing in at least three ways: 3D printing uses fewer machines and less material to make a part, uses less energy overall, and can require a much shorter and simpler supply chain than parts made through traditional methods. Unlike traditional machines, which cut or grind away as much as 90% of the feedstock, 3D printers generate less waste because products are made from little more than the amount of material included in the finished part. Because 3D printers make parts layer-by-layer, they use only as much material as needed to make each layer.

Operating 3D printers can also have a smaller energy footprint than what is required for traditional machines. Some people have argued that 3D printers use more energy to build a part than traditional machines. For example, the lasers and electron beams of metal 3D printers are said to use far more energy than traditional milling and drilling machines. They may be right if you look only at the energy used by the 3D printer; however, the all-in energy footprint of 3D printing should be smaller than that of traditional machines. Such all-in costs include making the manufacturing machines and the number of machines needed to make the part by traditional methods. Making a part with traditional processes requires multiple machines, all of which have their own energy footprint for manufacturing and shipping the machines themselves. All of those machines also gobble energy while they make parts. By comparison, a product can be 3D printed using far fewer machines, resulting in less overall energy usage. The all-in costs also include the price of the materials, including the quantity wasted by traditional machines.

While 3D printing a part uses more energy than traditional methods on a per-part basis, its energy footprint can be lower over the life of the part. For example, the fuel nozzles that GE Aviation 3D prints for its Leading Edge Aircraft Propulsion (LEAP) aircraft engine are 25% lighter than their traditionally made predecessors. Each LEAP engine contains 19 3D printed fuel nozzles. The lighter parts will save energy (in the form of jet fuel) over the life of the parts. GE expects to 3D print other parts for the LEAP engine, and eventually expects to shave 1,000 lbs from each 6,000-lb engine. Even if more energy is used to make each engine using 3D printing compared to traditional methods, the fuel savings over the life of each engine should leave a smaller energy footprint than a traditionally made engine.

As previously mentioned, traditional manufacturing is often done far from where the products are needed and used. The reason is that traditional manufacturing requires a lot of labor, so products are made where labor is cheap. In addition, this practice also requires shipping and warehousing. Labor, shipping and warehousing all have energy footprints. Because far fewer machines and less labor are required to 3D print parts and products, they need not be made in far-off lands, and the energy footprints can be reduced if the parts are 3D printed near the point of need. By using less material and energy, fewer machines and labor, shortening and simplifying supply chains, and reducing shipping and warehousing, 3D printing will help make the world a greener place.