Pros and Cons of Existing Hydrogen Technologies

  Each use of hydrogen as fuel has specific benefits and drawbacks. Hydrogen fuel cells are already in use as electrical generators, and they have also been used in the space program. Most experts believe the fuel cell is likely to be the dominant hydrogen technology in the future, not only for electrical generation but also to power vehicles. The only by-product of using a hydrogen fuel cell to power a car is water or water vapor, which exits through the tailpipe. However, hydrogen internal combustion engines (ICEs) are so similar to existing gasoline ICEs that they could be the best first use of hydrogen as a transportation technology for the general public. Also, like fuel cells, hydrogen ICEs do not produce harmful by-products.

Much of the impact of adopting hydrogen as an energy source would be positive for the environment. The use of hydrogen would likely come with a reduction of the use of fossil fuels as energy sources. With this reduction would perhaps come a reduction in global warming, because fossil fuel use is believed to be an important contributor to global warming.

However, the production of hydrogen can potentially affect the environment in a negative way. Depending on the production method, carbon dioxide and other negative emissions can enter the atmosphere while hydrogen is being made. This issue can be addressed by catching and storing the carbon dioxide, but even this storage can potentially affect the environment. However, if environmentally friendly, renewable resources such as solar or wind are used to power the means of producing hydrogen, the negative impact can be eliminated.

Another potential problem is that if hydrogen becomes widely used, it could leak into the atmosphere. If the amount is significant enough, this hydrogen could change the percentage of hydrogen present in Earth's atmosphere. Some scientists believe that this could have a profound effect on the atmosphere, including increasing the size of the hole in the ozone layer. More hydrogen in the atmosphere could also lead to more high altitude clouds and increase the number of soil microbes that rely on hydrogen as their primary nutrient. The soil microbe increase could change the ecology of Earth. However, there are soil micro-organisms that consume hydrogen as well, and they might be able to balance these problems out. The outcome of putting more hydrogen in the atmosphere is uncertain.

A final environmental question is what to do with the water or water vapor that would be produced by cars using hydrogen fuel cells. Since such water is pure, it will freeze in temperatures below 32F (0C). Scientists will have to come up with a solution for this by-product on the roadways and the environment in colder climates.

Pros and Cons of Hydrogen Fuel Cells

Hydrogen fuel cells have many good aspects. Fuel cells are very easy to make. They contain no moving parts. This means that there is little maintenance that needs to be performed on each fuel cell. Because they have no moving parts, fuel cells are quiet. Fuel cells are also light and versatile. They can be manufactured big or small and used on a large or small scale. Because they are modular in design, one can work on its own or many can function together as one. Hydrogen fuel cell-powered cars are very efficient producers of power. They are more efficient than internal combustion engine cars. About 60 percent of the potential energy in hydrogen is made into electricity by a fuel cell. These fuel cell-cars can respond instantaneously to provide fuel when it is needed.

Yet there are several major drawbacks to the development and use of fuel cells. One is the lack of a worldwide standard for fuel cells between manufacturers or most governments. Only one standardization agreement was in place as of 2005. It was between Japan and the European Union. This agreement covered hydrogen fuel cells for automobiles. Because no standards are yet in place, the development of the infrastructure needed to support hydrogen technology has been delayed. Governments and businesses do not want to invest money in creating an infrastructure that could be useless if it does not match the standards that others use.

The cost of the energy produced by a fuel cell is also very high. It costs more per kilowatt produced when compared to a gasolinepowered combustion engine. In 2002 a fuel cell could cost anywhere from $500 to $2,500 per kilowatt produced, while the combustion engine only cost about $30 to $35 for the same amount of energy. The costs for fuel cells have been going down as technology has been developed and improved.

Pros and Cons of Hydrogen-Powered Internal Combustion Engines

One positive aspect to hydrogen-powered internal combustion engines (ICEs) is that engineers at car companies are already experienced in the construction of such engines. The engines are similar to gasoline-powered ICEs. These types of ICEs are more familiar to automotive engineers than the technology of fuel cell engines. These vehicles will also be simpler internally than gasoline-powered cars. The catalytic converters and related systems found on gasoline-powered ICEs to clean up the by-products of fossil fuel combustion are not needed if hydrogen is used.

But hydrogen-powered ICEs have several disadvantages. The cars that use this type of engine are not as efficient as fuel cell-powered cars. Hydrogen ICEs can only extract about half of the chemical energy that is contained in a unit of hydrogen as compared to a fuel cell-powered vehicle. The vehicles also need more space to store fuel than gasoline-powered ICEs. These vehicles are built on current fuel tank sizes designed for gasoline or diesel fuel. Because hydrogen is not a very dense gas, the tanks cannot hold very much hydrogen. Therefore, the vehicles cannot travel as far.

Pros and Cons of Existing Hydrogen Technologies copyright 2011