Study finds alarming use of resources in newer manufacturing processes

Modern manufacturing methods are stunningly inefficient in their use of energy and materials, according to a detailed MIT (US) analysis of the energy use of 20 major manufacturing processes.

Overall, new manufacturing systems consume anywhere from 1000 to 1,000,000 times more energy, per kg of output, than more traditional industries.

In short, pound for pound, making microchips uses up orders of magnitude more energy than making manhole covers.

It may seem strange to make comparisons between such disparate processes as metal casting and chip making but, according to research leader Prof Timothy Gutowski of MIT’s Department of Mechanical Engineering, the comparison of energy efficiency is an essential step toward optimising these newer methods as they gear up for ever-larger production.

“The seemingly extravagant use of materials and energy resources by many newer manufacturing processes is alarming, and needs to be addressed alongside claims of improved sustainability from products manufactured by these means,” Gutowski and his colleagues say in their conclusion to the study.

Gutowski notes that manufacturers have traditionally been more concerned about factors like price, quality or cycle time, and not as concerned over how much energy their manufacturing processes use.

Solar panels, for example, use the same manufacturing processes as microchips, but on a larger scale. The inherent inefficiency of current solar panel manufacturing methods could drastically reduce the energy the panel saves over its entire lifetime.

According to Gutowski, as traditional processes have given way over the last several decades to newer systems for the production of current technologies, such as semiconductors, nanomaterials and MEMS, for a given quantity of output “we have increased our energy and materials consumption by three to six orders of magnitude."

The new study is just “the first step in doing something about it,” Gutowski said — understanding which processes are most inefficient and require less energy-intensive alternatives.

The study covered injection moulding, sputtering, carbon nanofibre production and dry etching, traditional machining, milling, drilling and melting.

It did not include production of pharmaceuticals or petroleum, and researchers looked primarily at processes where electricity was the primary energy source.