When it comes to looking to the energy source that will replace fossil fuels, there are no shortage of options. Solar power, wind energy, ethanol and biofuels are typically the most widely cited contenders to replace petroleum-based combustion engines and coal-fired power plants.
But hydrogen stands apart as a promising alternative energy source. Although the idea of hydrogen as a widely used fuel source to power cars and generate electricity is a relatively new concept in response to seeking an alternative to oil, hydrogen fuel cells actually predate the internal combustion engine, which was invented in the middle of the 19th century, by about 20 years.
Given that the most basic form of this technology has been around for nearly 150 years, why has its time suddenly come?
Hydrogen is the most abundant element in the universe, so there’s no chance of human consumers depleting the supply. There are certainly enough oil resources to meet global demand now, but many energy experts predict that the world’s supply of oil will be depleted within 60 years, according to a report from Ars Technica. It’s so easy to produce that the process could be completed at home with the right equipment.
Exhausting the world’s supply of oil or even approaching the inevitable shortfalls that come with a growing population — the planet now hosts 7 billion people as of the end of October — and economic growth will not only create a major energy crunch necessitating the rapid introduction of alternative energy sources; burning that much fuel also means an enormous burden on the atmosphere in the process. And that doesn’t even account for the potential environmental consequences of extracting crude oil from the Earth.
Hydrogen, by contrast, is clean-burning. The only byproduct of hydrogen power is water and heat, both of which can by recycled. This essentially means turning an energy consuming process into an energy producing one.
Hydrogen, however, is not a ready source of energy like oil and natural gas. Rather, it is a means of storing energy since pure hydrogen isn’t available on Earth in quantities necessary to fuel an entire energy economy. To get hydrogen in the form of a usable fuel requires energy. Hydrogen can be produced either by separating it from oxygen molecules in water through the process of electrolysis, or by splitting it off hydrocarbon chains in fossil fuels, a process that itself creates greenhouse gas emissions, as detailed in this article.
How does hydrogen generate usable power?
Hydrogen fuel cells don’t work quite like petroleum-based combustion engines, which rely on heat and power to create energy.
A fuel cell is made up of a stack, “a sandwich of anodes, cathodes and other high-tech materials,” as HowStuffWorks.com’s Ed Grabianowski explains. Liquid hydrogen fuel enters around the anodes, where electrons attached to the hydrogen are separated from the atoms themselves. An electrolyte within the fuel cell allows hydrogen protons to pass through, but not the electrons. When the hydrogen atoms reach the other side of the fuel cell, the cathode, it binds with oxygen, creating heat and water vapor.
What are the drawbacks of hydrogen?
Unless you happen to live in California, which has taken some initiative in building the infrastructure to support hydrogen fueling, chances are you’ve never seen the option of filling your car up with hydrogen last time you were at the gas station.
On the other side of the coin, if you’ve been to a car dealership recently, chances are you’ve seen vehicles with ordinary gasoline engines, diesels and probably even a few hybrids. But hydrogen-powered cars? Not likely.
And this one of the biggest hurdles to implementing a new energy technology: Energy producers and distributors need the infrastructure to supply demand for their fuel. But the demand cannot really exist without the infrastructure to support it. It’s like the “chicken and the egg” problem, but the difference is the solution is probably worth billions.
Another significant drawback of hydrogen is that, although it’s abundant, hydrogen fuel can be difficult and costly to store. At normal room temperatures, hydrogen exists as a gas. To get hydrogen into a liquid state that can be stored, transferred and eventually used as fuel requires a temperature of -423 degrees Fahrenheit (-253 degrees Celsius). Keeping hydrogen fuel that cold requires specialized containers such as the one in the photo to the left.
Finally, hydrogen-powered cars are currently too expensive for the average consumer to purchase. Last year, Toyota announced that by 2015 the car manufacturer intended to produce a hydrogen-powered vehicle that cost around $50,000, a 90 percent reduction in the current price of these same vehicles now, according to a report from Bloomberg News. At one point, production costs of each vehicle ran as high as $1 million.
In other words, while hydrogen is promising and has considerable attention and investment from energy companies and auto manufacturers alike, it’s time hasn’t yet come. So yes, hydrogen may be the fuel source of the future, but tomorrow, you’ll still probably need to fill your car with regular, old gasoline.