1. Hydrogen fuel is abundant and free.
There is hydrogen in fossil fuels, alcohols-even in water. Today, common ways of producing hydrogen include reforming natural gas (in which four hydrogen atoms are separated from a carbon atom) and electrolyzing water (which decouples two hydrogen atoms from an oxygen atom). The fact that hydrogen can be produced in so many ways means that, unlike petroleum, supplies of hydrogen can't run out, nor will they be concentrated in one area of the world. Hydrogen is everywhere-it just needs to be captured and used.
Capturing hydrogen, however, is not as easy as it sounds. There isn't much pure hydrogen around because hydrogen tends to bond easily with other elements. To make hydrogen fuel, hydrogen must be separated from whatever it's attached to, a process that requires energy. For this reason, hydrogen is often called an "energy carrier" rather than an energy source.
To get hydrogen, you first have to put energy in. For example, making a kilogram of hydrogen from water through electrolysis requires 45-70 kWh of electricity, depending on the technology. This amount of electricity could power the average American home for roughly two to three days.
2. Hydrogen fuel produces no emissions-just drop of clean water.
Let's assume that you are producing hydrogen through electrolysis-in other words, by using electricity to separate hydrogen atoms from oxygen atoms. Depending on where that electricity comes from, hydrogen can be clean and efficient or anything but.
In many areas of the country, electricity comes primarily from coal-fired power plants. Burning coal to generate electricity-and then using that electricity to make hydrogen-is not such a good idea. The hydrogen at the end of the process may be used in vehicles that are "clean," but the coal that was used to make the electricity emitted significant amounts of pollution and greenhouse gases. In addition, this process is not very efficient since losses occur each time one form of energy is converted to another.
However, if the electricity used to make hydrogen comes from renewable sources, such as hydroelectric, geothermal, solar, or wind, then hydrogen can be extremely clean. Hydrogen from renewables also releases no climate change emissions, and provides users with complete independence from fossil fuels. This is what appeals to hydrogen's supporters: the prospect of a fuel that is abundant, non-polluting, and safe for the world's climate.
3. The hydrogen highway is under construction and will be opened soon.
According to the Department of Energy, there are just 15 hydrogen stations in the United States, and 10 are in California. Hydrogen is hard to store onboard a vehicle, and it's also hard to store in tanker trucks, rail cars, and other equipment traditionally used to distribute liquid fuels. So we'll probably need to rethink our fuel distribution infrastructure in order to supply hydrogen effectively.
One advantage of hydrogen is that it can be made onsite at fueling stations or in people's homes using electrolyzers or natural gas reformers, so in the future hydrogen may give consumers more choice in locations to fuel their vehicles. But hydrogen infrastructure will take significant amounts of time and financial investment to develop, and many buyers will not want a hydrogen-powered vehicle until the refueling network is fully established.
Hydrogen has great promise as a future motor fuel. If hydrogen is made using environmentally sound methods and used in highly efficient fuel-cell vehicles, then the fuel offers a real solution to the problems of urban smog and climate change. However, much of the technology we need to make hydrogen vehicles a reality does not exist today. Hydrogen is a future solution, and we should be careful not to focus exclusively on hydrogen at the expense of other solutions that can be implemented today.