Modern Manufacturing Methods are spectacularly inefficient in their use of energy and materials, according to a detailed Massachusetts Institute of Technology (MIT) analysis of the energy use of 20 major manufacturing processes. Overall, new manufacturing systems are anywhere from 1,000 to 1 million times bigger consumers of energy, per pound of output, than more traditional industries.
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.
Gutowski notes that manufacturers traditionally have been more concerned about factors such as 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 the same manufacturing processes as microchips but on a large scale, is escalating dramatically. The inherent inefficiency of current solar panel manufacturing methods could reduce the technology's life cycle energy balance — that is, the ratio of the energy the panel would produce over its useful lifetime to the energy required to manufacture it.
The study is just “the first step in doing something about it,” Gutowski adds — understanding which processes are most inefficient and need further research to develop less energy-intensive alternatives. For example, many of the newer processes involve vapor-phase processing (such as sputtering, in which a material is vaporized in a vacuum chamber so that it deposits a coating on an exposed surface in that chamber), which is usually much less efficient than liquid phase, but liquid processing alternatives might be developed.