Jeff Wadsworth, President and CEO of the private nonprofit R&D company Battelle Memorial Institute, relies on two clichés to neatly sum up the energy topic. The first is that there is no silver bullet. “Although we started to hear that there might be silver buckshot,” he added, eliciting laughter from attendees of a “Powering the Future” session during the 2009 Materials Science and Technology (MS&T) Conference, held in Pittsburgh.
The second is there’s no free lunch. “What I mean by ‘no free lunch’ is it’s very tempting to say nuclear energy’s a problem because of the waste. But every energy supply source has problems—there are no free lunches,” Wadsworth said.
For example, solar and wind power may offer zero net carbon generation, but they also require “massive areas” for generation at scale, he noted. And electric vehicles—being heavily pursued for their promise of reduced point-of-use emissions and oil dependence—require, obviously, electricity.
“If you plug an electric vehicle into an outlet, you actually have to get the electricity from somewhere,” Wadsworth said. “Go back to square one, if that’s being generated using coal or oil or natural gas, you’ve not really solved the problem.”
In regard to energy, materials are part of the problem, too—and therefore a necessary part of the solution. That was the overriding message from experts speaking at the MS&T session.
Materials are a limiting factor for essentially all energy technologies, Wadsworth said. Clean coal, solar, biofuel, wind, electric vehicles, nuclear, fusion—they all rely on materials advances.
“You cannot advance any of these areas without understanding and developing new materials,” Wadsworth said, noting that fusion—being able to capture the reactions in the sun on Earth—“probably would represent the ultimate abundant fuel, but it’s a very, very tough problem.”
Each of these energy alternatives demands material properties that scientists and engineers have struggled with for a long time, Wadsworth said—notably higher strength and higher temperature in operation.
Catalysts are one “really important” area where advances need to occur, according to Steven Koonin, Undersecretary for Science, U.S. Department of Energy.
“We’ve got catalysts that can efficiently turn synthesis gas into long-chain alkanes in the Fischer-Tropsch process, and we’ve got a pretty good catalyst that will turn synthesis gas into methanol,” Koonin explained. “But catalysts that will produce molecules that are intermediate between those—such as ethanol, for example, out of syngas—would be a wonderful thing to have.
“And certainly the direct conversion of methane to methanol is a holy grail that we’ve not yet managed to seize, but would enable great efficiencies and better utilization of diverse feedstocks,” he added.
Energy storage is yet another significant area for materials development, as Yet-Ming Chiang, Kyocera Professor of Ceramics at the Massachusetts Institute of Technology and cofounder of lithium-ion battery maker A123Systems, shared.
“If we were to look at what’s necessary based on today’s battery technology to enable broad use—3000-lb, 200-mi range, all-electric vehicle at today’s battery metrics—that’s a battery about 1500 lb, about $40,000, and it would fill the back seat and trunk,” Chiang said. “So that’s where the materials challenges still lie—to get the cost down and get the energy density up.”
The question was posed, is there a need to worry about the supply of lithium, to which Chiang responded, “Today, there’s a glut of lithium,” the lowest-cost source of which is brine lakes. He noted that numbers from the U.S. Geological Survey suggest that a lithium shortage will not be an issue “for at least a couple of decades, if it ever becomes one.”
“Another point is the fact that unlike fossil fuels, when you use lithium it doesn’t go up in smoke. You can recycle it; it will be recycled,” said Chiang. “Also, the way that battery technology has progressed, it would probably not be a wise bet today to say that 30 years from now we’ll still be using lithium-based batteries.”
Regarding rare earth materials in batteries, Chiang noted that because of the need to drive down cost, the direction of battery chemistry has been toward more abundant, lower-cost materials.
“Cobalt has been the dominant transition metal for the past 15 years, but the new generation of lithium batteries uses iron and manganese…There aren’t substantial amounts of rare earth [materials] that are used today,” he said, adding that lithium battery producers are “much more concerned about cobalt and maybe nickel than they are about the rare earths.”
“Surprisingly, the cost of [energy] storage for mobile transportation is starting to look like it may eventually converge with large-scale stationary storage,” Chiang added.
Gregory Hildeman, Vice President of Engineering for Solar Power Industries, pointed out that all forms of energy—particularly renewable energy such as wind and solar photovoltaic—can benefit from energy storage.
“When the wind’s blowing, you can store that excess energy; when it’s not, you have batteries—same way with sunlight,” Hildeman said. “Having efficient batteries at all scales—whether they’re small batteries monitoring stream levels powered by photovoltaic systems, or large energy storage that takes some of the excess storage of electrical energy from the grid—that’s definitely needed.”