It is claimed that hydrogen fuel cells could be of the most important alternative technologies of future transport with current applications already visible. In fact, some scientists suggest that in 20 or 30 years from now hydrogen-powered, fuel efficient vehicles will be mass produced and utilized to respond to energy demands of the 21st century.
Hydrogen is the simplest and most abundant element in the universe. However, it does not come as an existing energy source like fossil fuels, but it is an energy carrier as it is produced first and following this process it is stored, similar to a battery. Since 2014, 95% of hydrogen is made from methane. The process to produce it involves using renewable sources, however it is expensive. Integrated wind-to-hydrogen plants, and using electrolysis of water to break down the H2O molecules have been amongst the technologies explored to deliver low enough costs and great enough qualities to compete with traditional energy sources. An alternative source to extract hydrogen is natural gas, which incorporates naturally occurring hydrocarbons. The procedure to separate the hydrogen in the gas from the carbon is called steam reformation and it is at present the most common method of large scale production of hydrogen, making it the most optimum solution for getting the hydrogen for fuel cell vehicles in any mass production. On the downside of this process however is that it uses fossil fuels — the natural gas – therefore it makes it the worst possible source for hydrogen if we intend to avoid depleting fossil fuel reserves.
How do hydrogen-powered vehicles work?
Hydrogen vehicles use hydrogen as the onboard fuel for motive power. Ranging from space rockets to automobiles, these hydrogen powered vehicles function either by burning hydrogen in an internal combustion engine or by reactions of hydrogen with oxygen in a device called a fuel cell. The latter is responsible for converting hydrogen to electricity, giving off heat and water. In this sense, it has been claimed that deployment of hydrogen vehicles could lead to decrease in the numbers of emissions from greenhouse gases and ozone precursors. In this sense, hydrogen cars have been proposed as fuel-efficient, eco-friendly, and green driving.
What are the challenges?
Any mass implementation of hydrogen-powered vehicles for transportation must first overcome certain challenges that fall into three categories: the first relates to the costs of developing the technology, the second on difficulties and dangers with hydrogen storage and the third on whether it is true or not that hydrogen is a “non-polluting technology”.
Developing hydrogen technology is not a simple task and thus it is quite expensive as it requires apart from the need to design and develop the fuel cells and the cars, also to develop an infrastructure to support these vehicles. Adding to this the extremely high costs to buy the car, it is no strange that these vehicles are currently for lease, not for sale.
The second concern in a vast utilization of hydrogen-powered transport is storage. Hydrogen is a gas and spreads out which means that squeezing it to a reasonable size to fit in a car is not an easy task. Even more, when hydrogen gets warm, further expands and it is therefore essential for the tanks to vent the hydrogen at times from the car. And hydrogen is highly flammable, so it should not be exposed to high temperatures.
The last problem or dilemma relates to whether hydrogen is actually not polluting the atmosphere. Although a hydrogen fuel cell produces only heat and water as exhaust, the procedures used to create the hydrogen as not as innocent. Electrolysis uses electricity and that electricity will often come from plants that burn coal, a highly polluting source. And when hydrogen is extracted from natural gas, it produces carbon emissions, which is exactly what we’re trying to avoid by using hydrogen in the first place.
What the research shows
Responding to the calls for a hydrogen economy, several companies are investigating technologies that might exploit the potential of hydrogen energy particularly in the motor industry. Several fleets of hydrogen fuel cell vehicles have emerged as a result since 2013, including Chevrolet Equinox Fuel Cell, Honda FCX Clarity, Hyundai ix35 FCEV and Mercedes-Benz B-Class F-Cell. In another field, that of space industry, NASA has already used hydrogen to launch space shuttles into space.
Despite several issues identified with the use of hydrogen powered vehicles, it is thought that these barriers will be overcome even if it takes several years. For others, any wide scale consumption of hydrogen vehicles is detouring from more readily available solutions such as hybrid electric vehicles and in addition it is far from the near future. It is therefore remained to be seen whether the energy demands for the transportation industry will be covered by hydrogen-powered fuel cells.