Hydrogen is the lightest, most abundant element on Earth. It’s non-toxic and non-poisonous. It will not contaminate groundwater and has the highest energy content per unit of weight of any known fuel. Isn’t that enough reasoning to support the ‘slam dunk’ concept of hydrogen fuel cells? Need more?
- Can be produced from a variety of plentiful domestic resources including natural gas, coal, biomass, and even water.
- Can meet increasingly strict government regulations for energy consumption.
- Currently used to power buildings, transit buses and other vehicles/machines throughout the world.
- Hydrogen fuel cell system require less components than most automotive power train systems.
- Waste is environmentally friendly (only water), has zero emissions and is non-pollutant.
The hydrogen fuel cell uses the reaction between hydrogen (most likely from a hydrogen-rich fuel) and oxygen from the air to produce electricity. Hydrogen and oxygen combine in the reaction, with the end products being electricity and water.
The fuel cell harvests the electricity created in the reaction. The amount of power produced by a fuel cell depends on several factors, including fuel cell type, cell size, the temperature at which it operates, and the pressure at which the gases are supplied to the cell.
An average single fuel cell usually generates only 0.7 volts of electricity, so usually hundreds of fuel cells are “stacked” together, combining their electrical outputs into enough electricity to power a car.
Hydrogen seems like the energy source we’ve been waiting for. There’s even a book that show you how to build your own fuel cells by Phillip Hurley titled Build Your Own Fuel Cells (www.goodideacreative.com/fuel_cell.html).
Currently, hybrid automotive vehicles only total 1% of the total market. So how do we move ahead to hydrogen fuel cells? Like any problem, several challenges must be addressed.
The most notable hurdle in this dilemma is cost. Cost includes the actual vehicle, battery/fuel cell and the hydrogen, which is currently about four times as expensive to produce as gasoline (when produced from natural gas, currently the most affordable procedure). Fuel cells are approximately ten times more expensive than internal combustion engines
Although hydrogen has the highest energy content per unit of weight of any known fuel, it’s difficult to contain because it has much less energy by volume than other fuels. This elemental property makes it difficult to store a large amount of hydrogen in a small space, like in a gas tank of a car.
Hydrogen can easily carry and delivery energy. It combines easily with other materials and liquids. Hydrogen is also odorless, colorless, and tasteless, so there would be a need for sensors to ensure safe guidelines and usage. Hydrogen does burn very quickly and can even make a loud noise that’s often mistaken for an explosion, but is generally perceived as safe because hydrogen moves upwards and away very quickly once released from storage.
Explosions could only occur in a container holding only hydrogen when an oxidizer, such as oxygen, is present. Current storage designs promote designs that further expedite the hydrogen away from users in case of an unexpected release.
Current public perception of hydrogen fuel cell technology directly relates to conventions and practices of the current gasoline technology. Most people might not even consider attempting to build a fuel cell. A fuel cell? Couldn’t that blow up? People may have a hard time even considering building something that could provide power for their car, but more importantly, actually buy into the concept in the first place.
Various social concerns also factor into hydrogen fuel cell technology. Several high-profile concerns and conflicts surrounding current energy sources, mainly oil, could be alleviated by hydrogen fuel cell use.
Potential energy shortages, most notably experienced in the early 70s, and reliance on imported oil, currently at 11 million barrels a day used for transportation (approximately 20 million a day total), are probably the two biggest concerns.
The United States currently imports 55 percent of total oil consumed, which is expected to grow to 68 percent by 2025, about the same time when the first wave hydrogen fuel cell vehicles are expected to flourish.
So how can we implement this problem solving technology and envision an infrastructure to sustain it? First it helps to understand where we’ve been.
The first gasoline station was built in 1907, a time when the Census reported more than 140,000 registered motor vehicles. How did this infrastructure support all the cars? Doesn’t the lack of fueling stations make the vehicles less marketable?
Well, it’s important to note that the owners of the cars were very wealthy and were often employed at groundbreaking gasoline refineries were fuel was readily available to them.
This scenario echoes through today’s infrastructure where rich tycoons and privileged company employees at developing hydrogen fuel cells already enjoy extensive use of these special vehicles.
We’ve relied on our current transportation energy source of gasoline for more than 50 years; so many people have conceived that an update is long over due. This crucial time requires careful planning of an infrastructure that supported the automobile.
The current infrastructure uses two main practices for hydrogen storage/delivery, high pressure compressors (for gaseous hydrogen) and liquefication (for cryogenic, or liquid hydrogen). Storage materials mainly consist of cylinders, tube trailers, cryogenic tankers, and in pipelines constructed of regular pipe steel (approximately 720 km in U.S.A. and 1,500 km in Europe).
Several alternatives in hydrogen storage and/or delivery are currently in research stages. One alternative is a materials-based method where hydrogen can be stored within solid materials, such as powders, which takes advantage of hydrogen’s ability to combine quickly with other materials.
A solid hydrogen storage system would absorb hydrogen in a metal powder by bonding the hydrogen and powder together by removing heat in an absorption process. Hydrogen would then be released out of the metal powder and into the vehicle’s fuel system by adding heat.
Nano-porous materials, which have tiny pores that are one hundred-thousandth (100,000th) the thickness of a sheet of paper have also been explored so the hydrogen could be applied at a higher pressure increasing overall efficiency and power.
Other materials such as special ceramic membranes are being developed to provide denser quantities of hydrogen for increased energy. Ideally, hydrogen remains relatively free from impurities when operated at temperatures below 100° C (212° F), so materials that are resistant to extremely high temperatures are required.
The ‘slam dunk’ concept of the hydrogen fuel cell is certainly within reach, but, like the automobile, the final decision lies with the consumer. If people don’t accept and use the technology, then hydrogen fuel cells will remain only a proprietary source of energy, instead of a widespread solution to several economic, environmental and social concerns.