It wasn’t long ago that futurists were predicting the ascendancy of clean, quiet electric cars that would be plugged in at home to recharge. A new version of the future turns that scenario upside down: The house plugs into the car and draws whatever power it needs from the vehicle’s engine.
It’s not such a crazy idea. Most people don’t realize it, but making a car go takes much more energy than powering everything in the typical house. If cars ran on a more efficient, nonpolluting system such as fuel cells instead of by the combustion of gasoline, they could quietly and safely generate all the electricity a house needed from the garage. (Batteries would be needed to take over when the car was away.)
Many practical problems need to be overcome before fuel-cell cars can double as home power plants. A team of researchers led by Paul McGinn ’80, ’83M.S., ’84Ph.D, Notre Dame professor of chemical and biomolecular engineering, is trying to solve some of them.
The researchers are actually working under a grant from the Army, which has its own vexing power problems. Today’s military relies on an array of electronic communications equipment, global-positioning targeting instruments and other devices, most powered by batteries. During the conflict in Iraq, military planners found that soldiers in the field depleted batteries in their high-tech gadgets faster than fresh supplies could be delivered.
Fuel cells promise longer-lasting, easily replenished power. Like batteries, they generate DC current through a chemical reaction. In the fuel cell, it’s the reaction between hydrogen gas and a catalyst, usually platinum. The reaction ends with hydrogen gas combining with oxygen from the air to produce a nonpolluting exhaust — water vapor. As long as the hydrogen keeps pouring past the platinum catalyst, the reaction keeps producing electricity and water vapor.
It sounds like a great system, which is why it has received so much attention lately, including a proposal by President Bush in his 2003 State of the Union address to spend $1.2 billion on fuel cell development.
Unfortunately, even the most advanced cells of today are too heavy and expensive. An engineer at the University of California Berkeley has estimated that a fuel cell powerful enough to run a car today would cost $300,000.
One of the objectives of McGinn’s research is to find a cheaper substitute catalyst for expensive platinum. In case there isn’t one, he’s also exploring ways to reduce the amount of platinum needed. As the engineer points out, “There has not been enough platinum mined [in all of history] to run all the cars in the United States at the present levels of platinum loading.”
The most formidable stumbling block for fuel cells, though, isn’t the scarcity of platinum but of hydrogen. Paradoxically, the element is the most abundant in the universe, but on earth it’s all bound up with other elements, as with oxygen in water. Separating out hydrogen from these compounds takes a lot of energy. And if the energy to do this comes from fossil fuels, not much will have been gained in terms of energy and reducing pollution.
McGinn says he’s optimistic that many of the problems of fuel cells can be overcome and that the technology can at least be integrated such with alternative energy sources as solar and nuclear power. But like other researchers, he sees the growing euphoria over fuel cells as premature.
“Everyone sees fuel cells as this panacea, which they may not be.”