Could hydrogen be the fuel of tomorrow?

As we explore the future of energy and search for viable alternatives to fossil fuels, there is an abundance of potential options. Solar power, wind energy, ethanol, and biofuels are among the most commonly discussed candidates to replace traditional petroleum-based engines and coal-burning power stations.

Hydrogen, however, stands out as a particularly promising energy source. Although the concept of hydrogen powering vehicles and generating electricity is a recent development in the quest for an oil alternative, hydrogen fuel cells actually predate the invention of the internal combustion engine by nearly two decades, having been conceived in the early 19th century.

Given that the fundamental form of this technology has existed for almost 150 years, why has it gained so much attention now?

Why hydrogen?

Hydrogen is the most plentiful element in the universe, ensuring its availability for human use. While there are sufficient oil reserves to meet global demand today, many energy experts forecast that the world's oil supply will run out within the next 60 years, according to a report from Ars Technica. The production of hydrogen is so simple that it could even be done at home with the appropriate equipment.

Depleting the world’s oil reserves, or even approaching the inevitable shortages triggered by a growing population — which reached 7 billion people by the end of October — and economic expansion, will not only lead to a severe energy crisis that demands rapid adoption of alternative energy sources, but also place immense strain on the atmosphere in the process. And this doesn’t even consider the potential environmental damage caused by extracting crude oil from the Earth.

Hydrogen, on the other hand, burns cleanly. The only byproducts of hydrogen fuel are water and heat, both of which can be recycled. Essentially, this transforms an energy-consuming process into an energy-producing one.

However, hydrogen is not an immediate source of energy like oil or natural gas. Instead, it serves as a means of storing energy, as pure hydrogen is not found in quantities sufficient to power an entire energy economy. To make hydrogen usable as a fuel, energy is required. Hydrogen can be produced by either separating it from oxygen molecules in water through electrolysis or by extracting it from hydrocarbon chains in fossil fuels, a process that itself generates greenhouse gas emissions, as explained in this article.

How is hydrogen used to generate power?

Hydrogen fuel cells operate differently from petroleum-based combustion engines, which rely on heat and power to generate energy.

A fuel cell consists of a stack, described as 'a sandwich of anodes, cathodes, and other advanced materials,' according to Ed Grabianowski of Mytour.com. Liquid hydrogen fuel flows around the anodes, where electrons are separated from the hydrogen atoms. An electrolyte within the fuel cell allows hydrogen protons to pass through but blocks the electrons. Once the hydrogen atoms reach the cathode side of the fuel cell, they combine with oxygen, producing heat and water vapor.

What are hydrogen’s limitations?

Unless you're in California, where significant efforts have been made to build infrastructure for hydrogen fueling, you're unlikely to have seen hydrogen fuel as an option at your local gas station the last time you filled up your car.

On the flip side, if you've visited a car dealership recently, it's likely you've encountered vehicles with traditional gasoline engines, diesels, and possibly even a few hybrids. Hydrogen-powered cars, however? Not so much.

This represents one of the key obstacles in adopting a new energy technology: Energy providers and distributors must establish the necessary infrastructure to meet fuel demand. However, demand can't truly emerge without that very infrastructure in place. It's akin to the 'chicken and egg' dilemma, but in this case, the solution could be worth billions.

Another notable challenge of hydrogen is that, although it's plentiful, hydrogen fuel is difficult and expensive to store. At normal temperatures, hydrogen is a gas. To convert hydrogen into a liquid form for storage, transport, and eventual use as fuel, it needs to be cooled to -423 degrees Fahrenheit (-253 degrees Celsius). Maintaining such low temperatures requires specialized storage containers, such as the one shown in the photo to the left.

Lastly, hydrogen-powered vehicles remain too costly for the average consumer. Last year, Toyota declared its intention to produce a hydrogen-powered vehicle by 2015, priced around $50,000—90 percent less than current hydrogen-powered vehicles, according to a Bloomberg News report. At one point, the manufacturing cost of each car was as high as $1 million.

In essence, while hydrogen holds great potential and has garnered considerable interest and investment from both energy companies and auto manufacturers, it's not quite ready for prime time. So, while hydrogen may one day fuel the future, for now, you're still likely to fill your car with regular gasoline.