The new study is just "the first step in doing something about it," Gutowski says 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 (such as depositing a coating from a liquid solution), but liquid processing alternatives might be developed.
The study covered everything "from soup to nuts" in terms of standard industrial methods, Gutowski says, "from heavy-duty old fashioned industries like a cast-iron foundry, all the way up to semiconductors and nanomaterials." It includes injection molding, sputtering, carbon nanofiber production and dry etching, along with more traditional machining, milling, drilling and melting. There were some boundaries on the processes studied, however: The researchers did not analyze production of pharmaceuticals or petroleum, and they only looked primarily at processes where electricity was the primary energy source.
The figures the team derived are actually conservative, Gutowski says, because they did not include some significant energy costs such as the energy required to make the materials themselves or the energy required to maintain the environment of the plant (such as air conditioning and filtration for clean rooms used in semiconductor processing). "All these things would make [the energy costs] worse," he says.
The bottom line is that "new processes are huge users of materials and energy," he says. Because some of these processes are so new, "they will be optimized and improved over time," he says. But as things stand now, over t
|Contact: Elizabeth Thomson|
Massachusetts Institute of Technology