With continuing information about the negative externalities around fossil fuels, as well as their imminent decline, the need to find alternative clean energy sources to replace oil. When it comes to certain energy expenditures such as automobiles the idea of using hydrogen has become a very common topic in this collective conversation. Hydrogen is a difficult solution to this problem due to a number of intricate factors including cost, energy needed for production, chemical safety, and the technology needed to create and ship it in bulk.
A hydrogen fuel cell, put simply, is a device that uses both stored hydrogen and incoming or provided oxygen (usually from air) to produce electricity for consumption. The by product of this is both heat and water as opposed to toxic emissions. The cell in its design parallels conventional batteries, with one electrode for hydrogen passage and the other for oxygen. The electrode transforms the hydrogen into negatively charged electrons and positively charged ions. The electrons are then tapped for their electrical energy potential. Then the ions continue their journey, unite with the oxygen, and turn into water.
Though the process of the cell appears elementary, the issues surrounding its delay are concrete. Hydrogen safety is an important issue in the development of this technology because of its high energy content and possibility for large scale incident. This can be referenced as the incident with the Hindenburg disaster as well as the hydrogen bomb.
Secure methods are needed for its transport, but these precautions are observed for all current hydrogen transfer and there is no viable reason that this would not be the case when distribution hits a larger scale. Storage is also a mentioned problem when it comes to the hydrogen fuel cell because the gas itself is of low density and it is difficult to compress a sufficient amount into a space needed for consumer products like cars.
Another key point here is that since hydrogen does not just appear naturally on Earth it must be extracted using technology with energy consumption itself. This would require energy stations that would have to power the extraction process without using more energy resources than are being produced. This is an issue that can be done by using natural energy sources in key areas. Examples of this would be large wind-energy collectors in Colorado or solar panels in Nevada as prime areas to house plants for hydrogen production.
A specific use of this idea would be in the Solar Hydrogen Cycle. Photovoltaic panels are used to collect solar energy which is then used to power an electrolyzer. This device is used to split water into its sub-parts, hydrogen and water. The water is discharged and the hydrogen is stored for transfer.
Storage, which is one of the most persistent issues, is also being attacked by companies with stake in hydrogen. It has been addressed with new technologies such as nanostructured carbons. These can store large amounts of hydrogen at near to room temperature.
Once these challenges have been met the economic appropriateness of hydrogen fuel cells in the general consumer market can be presented. What is difficult to estimate is the time it would take to continue developing the technologies to secure fuel cells as a fully marketable fuel source, which adds a dimension of price. When the Renewable Energy Policy Project has released estimates for fuel cells for 2002 it had dramatically low numbers for common consumer use. It is a variable price range which changes with the technology using it and the application requiring it. For transportation it is set at about $50 per kW, while to for residential are marked at about $300 to $500 per kW. This low price is a stark difference from the cost of distributed commercial, which ranges from $1200 to $3000 per kW. It is questionable whether this estimate will be similar for the 2008 summary.