Modern manufacturing methods are spectacularly inefficient in their use of energy and materials, according to a detailed MIT analysis of the energy use of 20 major manufacturing processes.
Overall, new manufacturing systems are anywhere from 1,000 to one million times bigger consumers of energy, per pound of output, than more traditional industries. In short, pound for pound, making microchips uses up orders of magnitude more energy than making manhole covers.
At first glance, it may seem strange to make comparisons between such widely disparate processes as metal casting and chip making. But Professor Timothy Gutowski of MIT's Department of Mechanical Engineering, who led the analysis, explains that such a broad comparison of energy efficiency is an essential first step toward optimizing these newer manufacturing 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," Gutowksi and his colleagues say in their conclusion to the study, which was recently published in the journal Environmental Science and Technology (ES&T).
Gutowksi 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. This latter issue will become more important, however, as the new industries scale up -- especially if energy prices rise again or if a carbon tax is adopted, he says.
Solar panels are a good example. Their production, which uses some of the same manufacturing processes as microchips but on a large scale, is escalating dramatically. The inherent inefficiency of current solar panel manufacturing methods could drastically reduce the technology's lifecycle energy balance -- that is, the ratio of the energy the panel would produce over its useful lifetime to the energy required to manufacture it.
Adapted by Science Daily from materials provided by Massachusetts Institute of Technology.