A recent study of the energy use in 20 major manufacturing processes, conducted by the Massachusetts Institute of Technology (MIT), reveals that modern manufacturing methods are inefficient in their use of energy and materials.
The study shows that manufacturing systems consume anywhere from 1,000 to one million times more energy, per pound of output, than more traditional industries. Upshot: Making microchips consume orders of magnitude more energy than making manhole covers.
The study, funded by the National Science Foundation, covers everything from standard industrial methods found in older industries such as cast-iron foundries to semiconductor manufacturing and nanomaterials. It includes injection molding, sputtering, carbon nanofiber production and dry etching, together with more traditional machining, milling, drilling and melting. However, the researchers did not analyze production of pharmaceuticals or petroleum, and they looked primarily at processes where electricity was the major energy source.
Professor Timothy Gutowski of MIT's Department of Mechanical Engineering, who led the analysis, said that such a broad comparison of energy efficiency is an essential first step toward optimizing these newer manufacturing methods as they gear up for large-scale production. He said the use of energy and materials in "newer manufacturing processes is alarming and needs to be addressed alongside claims of improved sustainability from products manufactured by these means."
For example, the production of solar panels, which uses some of the same manufacturing processes as microchips but on a large scale, is escalating dramatically. According to the study, the inherent inefficiency of current solar panel manufacturing methods could significantly reduce the technology's lifecycle energy balance -- the ratio of the energy the panel would produce over its useful lifetime to the energy required to manufacture it.
Gutowski said the study is the first step towards developing less energy-intensive alternatives. The study cites 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), as an example, which is typically less efficient than liquid phase (such as depositing a coating from a liquid solution), but liquid processing alternatives might be developed.
Despite the study's conclusions, manufacturing industries such as the video display market are making efforts to implement sustainable practices. In addition, many major companies including Boeing, Coca-Cola and General Mills say cleaner, safer and more energy-efficient manufacturing practices are a necessity during economic downturns.
