Fuel Cells do not create pollution or toxic byproducts, as do fossil fuels or nuclear energy. Fuel Cells use the most commonly available substance on Earth, hydrogen, as part of its fuel. It emits heat, which can be tapped in certain applications such as space or water heating, and water as byproducts. Fuel Cells are also more energy efficient than gasoline or diesel engines. The lack of moving parts in Fuel Cells contributes to their low maintenance cost. Fuel Cells also run very quietly compared to other sources of energy.
Problems with Fuel Cells
Fuel Cells are currently very expensive, costing about 4500 dollars per kilowatt, as opposed to 800 to 1000 dollars per kilowatt for a diesel engine. There are also problems with using hydrogen as fuel. Hydrogen is one of the most volatile substances on Earth, prone to combustion. It is also more difficult to store in a fuel tank than, say, gasoline. Also the hydrogen has to be very pure or else it would begin to damage the catalyst. Hydrogen has to be extracted from sources like water or natural gas, generating more energy costs. Finally, the most common material used as a catalyst, platinum, is rare enough on Earth that if every car on the planet were converted from internal combustion engines to fuel cells, there would not be enough platinum to build the fuel cells.
Solutions
Research and development is ongoing to decrease the cost and increase the efficiency of fuel cells. Hydrogen can be extracted from water or natural gas using nonpolluting energy sources such as solar. Fuel processors can be added to fuel cells that would extract hydrogen from natural gas—for example. This would allow cars to be powered by natural gas. One problem is that while even this technology produces less pollution than standard gasoline and diesel engines, it still produces significant amounts of carbon dioxide, which is a cause of global warming.
The shortage of platinum as a catalyst can be addressed in one of two ways. Other materials can be found to serve as a catalyst. Research is ongoing in this area. The second method is to find other sources of platinum and related metals. Aerospace engineer Dennis Wingo has suggested that there are sources of these materials on the Moon or Earth approaching asteroids that can be mined economically, if the decision is made to convert to a hydrogen economy.