Highly efficient vehicles with no polluting emissions
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Fuel cells were invented in 1839, powered the Gemini and Apollo space missions, and still provide power on the space shuttle. But perfecting them for use in cars still poses a challenge. Scientists at the Laboratory are developing new materials to make fuel cells cost-effective, durable, and vehicle-ready.
One day soon, these highly efficient powerhouses could replace internal combustion engines, so that our cars burn less fuel, and give off nothing more than the harmless emission of ordinary water.
Decreasing Foreign Oil Dependence
The United States consumes much more oil than we produce domestically. In 2007, the U.S. produced 5.1 million barrels of oil per day, but consumed 20.7 million barrels per day according to the Energy Information Administration, which provides energy statistics from the U.S. government. The result is that the U.S. imports significant amounts of oil, and is dependent upon foreign countries for its oil supply.
Fuel cells, which utilize hydrogen instead of gasoline or diesel fuel, would greatly reduce that dependence.
Emissions of Pure Water
Fuel cells are similar to batteries; they convert chemical energy into electricity. However, unlike batteries, fuel cells use chemicals that are external to the fuel cell. The types of fuel cells LANL scientists develop convert hydrogen and oxygen (from air) into electricity and water. The system utilizes a thin membrane and catalysts – often made of platinum – to electrochemically convert the hydrogen and oxygen into electricity.
"Of course, environmentally we love fuel cells because hydrogen plus oxygen makes water," says Rod Borup, program manager for the Laboratory's fuel cell program in MPA-11, the Sensors and Electrochemical Devices Group.
Scientists at the Lab are developing better materials and technologies to improve the different components of the fuel cell. These improvements include decreasing the costs of the catalyst, improving the materials that make up the membranes, understanding what degrades the performance of fuel cells including the effects of fuel and air impurities, understanding water management inside the cell, and improving on-board vehicle hydrogen storage.
Superior Fuel Efficiency
One of the biggest advantages of fuel-cell powered vehicles is their efficiency as compared to conventional internal combustion engines.
A gasoline-powered engine is about 22 percent efficient, Borup says. That means that 22 percent of the fuel you put into your car is used to power the vehicle, and the remainder is wasted as heat. A diesel-powered vehicle runs at about 27 percent efficiency, a hybrid electric vehicle, about 30-35 percent.
By contrast, fuel cell vehicles can run at 55 percent efficiency. They simply burn less fuel.
Replacing an Old Standard
Besides the technical challenges the Lab is addressing, fuel cell acceptance may require a sea change in the public's way of thinking. "Internal combustion engines are very reliable, and performance is good," Borup says. "With fuel cells, we are trying to put something on the market that displaces existing technologies."
To begin to adjust the American mindset, the world's major automakers are rolling out prototypes of fuel cell cars. Prototype fuel cell forklifts, busses, and stationary building power supplies are in use around the globe. "Our part at the Lab is to make better materials for fuel cells, and to help give the automakers and others a better perspective on how to use fuel cells," Borup says.
The Department of Energy is targeting the year 2015 for a decision on the commercial viability of fuel cells, he says.
Further, DOE's goals are to have on-board hydrogen storage systems that provide fuel for a 300-mile range, says Kevin Ott, MPA-MC group leader and national program leader for the Department of Energy's Hydrogen Storage Center of Excellence. The DOE is aiming for a market penetration of 10 million vehicles by 2025, Ott says.
The Department of Energy's Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time.