Emissions from gasoline and diesel vehicles—such as nitrogen oxides, hydrocarbons, and particulate matter—are a major source of this pollution. Hydrogen-powered fuel cell electric vehicles emit none of these harmful substances—only water H 2 O and warm air. The environmental and health benefits are also seen at the source of hydrogen production if derived from low- or zero-emission sources, such as solar, wind, and nuclear energy and fossil fuels with advanced emission controls and carbon sequestration.
Because the transportation sector accounts for about one-third of U. Learn more about hydrogen emissions. Hydrogen's energy content by volume is low. This makes storing hydrogen a challenge because it requires high pressures, low temperatures, or chemical processes to be stored compactly. Overcoming this challenge is important for light-duty vehicles because they often have limited size and weight capacity for fuel storage.
Typically, the storage capacity for hydrogen in light-duty vehicles should enable a driving range of more than miles to meet consumer needs. Because hydrogen has a lower volumetric energy density than that of gasoline, storing this much hydrogen on a vehicle currently requires a larger tank at higher pressure than other gaseous fuels. One hope for our energy future lies in hydrogen -- an infinitely renewable and relatively pollution-free fuel that scientists and politicians alike see as a viable alternative to fossil fuels.
Department of Energy ]. So does hydrogen fuel cell technology live up to its promise of delivering a clean and efficient energy source? That depends on how it's produced. On the one hand, hydrogen is plentiful in sources such as natural gas and water -- and unlike fossil fuels, hydrogen is relatively gentle to the environment. In fact, it's essentially pollution-free. A hydrogen fuel cell in a car produces zero emissions; the only substances released through its tailpipe are water vapor and heat.
Producing hydrogen fuel cells doesn't release pollution either, provided that renewable sources such as water or solar energy are used in the production process.
And if that wasn't enough, hydrogen fuel is about three times more efficient than gasoline [source: US News ]. Then again, hydrogen isn't always clean to produce. It's expensive to pull hydrogen from water. Non-renewable sources of hydrogen, such as oil and natural gas, are much cheaper, but using them still puts a drain on our fossil fuels supplies.
Ironically, the carbon dioxide released in the process of producing hydrogen from fossil fuels cancels out any benefits to the environment. Experts say hydrogen that escapes during the production process could erode the ozone layer even further and exacerbate global warming [source: PBS].
There are other problems as well: Scientists are still struggling with the challenge of how to store hydrogen. Because it has such a low energy density, hydrogen needs to be stored and transported under high pressure -- which makes it bulky and impractical. The pressure issue compounds another issue with hydrogen energy; like gasoline, hydrogen is highly flammable, but unlike gas, it has no smell.
Sensors must be used to detect a leak before hydrogen can combust. Another issue is the need to provide enough refueling stations to supply all the hydrogen-powered cars throughout the country. Are hydrogen fuel producers willing to put a hydrogen station on virtually every corner?
Are you still fuzzy about hydrogen and hydrogen fuel cell technology? The next page covers all the basics. Hydrogen is the most basic and most common element on Earth. Represented by the letter "H" on the periodic table, hydrogen is a gas that combines with oxygen to make water H 2 O , and with carbon to form compounds such as methane and coal. Hydrogen is also a potent source of clean energy. In fact, it has the highest energy content of any fuel we use today [source: U.
Energy Information Administration ]. Hydrogen itself isn't available on Earth, but it can be produced. The transportation sector has been asked to bear the brunt of the responsibility for reducing greenhouse gases even though it contributes only one-third. The idea of piping hydrogen into homes or businesses seems far-fetched, but it is possible.
The current liquid natural gas infrastructure could be modified for hydrogen. Cars that run on kelp. Cosmetics made from waste. USC Dornsife researchers are creating new products designed to both mend the planet and make it in the marketplace. An aerospace and mechanical engineer explains how to bring this fuel down to Earth. What benefits do hydrogen fuel cell-powered cars offer? Hydrogen-fueled cars sound squeaky clean.
Can hydrogen be made without creating greenhouse gases? Hydrogen is only as clean as the energy used to produce it.
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