"Of the 10 biggest problems perceived to be facing the world today, No. 1 is our need for energy," said Héctor Abruña, an expert in fuel cell technology, at the American Museum of Natural History's SciCafe in New York City March 3.

Speaking on "Fuel Cells: A Look Into the Future of Energy Technology" at the Gottesman Hall of Planet Earth, Abruña, the Emile M. Chamot Professor of Chemistry and director of the Cornell Fuel Cell Institute and Energy Materials Center, discussed a range of solutions to meet the world's energy needs, including hydrogen, solar, nuclear and wind.

"The world uses 13 terawatts of power," Abruña told the capacity crowd, many with chemistry and physics degrees, "a quarter of it by Americans." With almost all that energy produced from fossil fuels, "it is certain, they will run out," he said.

He noted that fuel cells are an important option for the future. However, he noted, "They are used best in a stationary setting with enough space so you can turn them on and leave them alone, not necessarily a car." Fuel cells chemically decompose fuel, turning the energy into electricity. The Cornell Fuel Cell Institute is working to develop new materials to do that more efficiently.

"The best energy solution depends on where you are located," said Abruña. "In Arizona the sun looks great, but in Kansas, wind looks better." The idea for a hydrogen economy seems difficult, too, he reflected. "Hydrogen takes energy to separate," and where that energy comes from becomes a complication. Similarly, according to Abruña, nuclear power doesn't seem feasible. "We would need to build too many nuclear power plants to meet our energy demands."

Abruña also discussed the need to develop new ways to store energy, especially the energy from renewable, intermittent sources such as win and solar. "New types of batteries and capacitors will need to be developed," said Abruña. "Lead batteries were invented 100 years ago. In 20 years, we will be done with them."

To replace traditional batteries, lithium-ion batteries, already used for cell phones and computers, may be the answer. "Lithium-ion has a higher energy density than TNT," said Abruña. "The drive from the market will be for ever-increasing energy density" allowing greater amounts of energy to be stored in one battery. Future possibilities include lithium-air, the "holy grail" of batteries, in which a "lithium anode is electrochemically coupled to atmospheric oxygen through an air cathode," and 3-D batteries that use nanotechnology to create a more efficient link between an energy storage source and its electrodes.

"Electricity is by far the most efficient way to utilize energy," Abruña argued. Electricity has low entropy, meaning it doesn't dissipate. Electric motors are more efficient than combustion (heat) engines. Today, however, the electric grid can't accommodate a complete shift to electric cars, and the investment to improve the infrastructure would be enormous, said Abruña. But, he said, electric cars will come to market before fuel cell cars.

Ironically, when asked if there were a solution to the world's energy needs, Abruña said, "we already have all the energy we need in the sun. We just haven't found a good way to utilize and store it."

John Mikytuck '90 is a freelance writer living in New York City.