Tech Tuesday: Hydrogen Power
No matter where you stand on climate change — Al Gore, or loving doing burnouts with your six-wheeled Hummer — there are a few undeniable facts that I think everyone can agree upon. First, we like fossil fuels — a lot. According to the U.S. Energy Information Administration, North America (including the United States, Mexico, and Canada) consumed an average of nearly 23.5 million barrels of petroleum products a day in 2013, with the U.S. gobbling up about 19 million barrels all by itself. Then there are coal and natural gas, which combine with oil to create 67 percent of electricity generated stateside, with coal accounting for 39 percent of that.
Clearly, it’s important stuff. These three energy sources essentially created modern civilization. But there’s a problem. I’m talking about supplies. According to one study, world oil reserves are projected to run dry in just 35 years. Of course, this projection is based on myriad factors that will probably change; new reserves will be found and consumption will fluctuate. But the writing is on the wall – we’re going to need a new source of motive power eventually.
Now, I’m not here to frighten anyone or moralize on lifestyle choices (although you should probably find a secluded parking spot for your Hummer). I’m here to talk about the future of the automobile, one where gasoline has gone the way of the dinosaur. So, without petroleum, what do we have?
Hydrogen is looking like our best bet. Several automakers are developing not only the cars to use it, but the infrastructure to support it. But what is hydrogen power, and most importantly, how will it change the face of the automotive world?
Click past the jump to read more about hydrogen power.
How It Works
Hydrogen is the simplest and most abundant element in the world. Unfortunately, you can’t find hydrogen by itself — it’s always tied up with some other molecule. Producing hydrogen fuel is therefore a process determined by the source material.
According to FuelCells.org, about half of the world’s hydrogen fuel is created from methane gas (CH4), which is broken down through a process called steam-methane reformation. Basically, natural gas “reacts with steam in the presence of a catalyst to produce hydrogen, carbon monoxide, and a relatively small amount of carbon dioxide.”
Water is another good source of hydrogen fuel. Electricity (electrolysis), nuclear radiation (radiolysis), or a combination of heat and chemical reactions (thermochemical) can be used to isolate the H2 from the O. Alternatively, you could use something called an algae bioreactor, which deprives algae of sulfur, prompting it to produce hydrogen instead of oxygen during the normal photosynthesis process.
These processes just scratch the surface of hydrogen production, but given the element’s ubiquitous nature, we are sure to see additional methods evolve as demand increases.
While hydrogen has three times the energy density per unit weight compared to gasoline, it also has a very low volumetric energy density. Basically, that means scientists have been looking for the optimum way to pack a lot of hydrogen fuel into a compact, transportable space.
So far, there are three solutions on the table. For cars, the most common is compressed hydrogen, which uses high pressure to stuff as much H2 as possible into a holding tank. Next, there’s “slush” hydrogen — a favorite with space programs — wherein the gas is super-cooled to a liquid. Finally, there’s solid hydrogen, whereby the element is combined with chemicals to form a hard, compact substance. While promising, this last form of hydrogen fuel is still very much under development.
Making The Go
So you’ve extracted the hydrogen and got it into your car. Now what? A hydrogen fuel cell stack is essentially comprised of an anode and a cathode, with an electrolyte layer sitting in between. Hydrogen enters the anode side, while oxygen from the atmosphere enters the cathode side. When the two elements combine, the result is water (H2O), heat, and an electrical current. Those electrons are consequently directed towards a battery, which powers an electric motor.
Zero Carbon Emissions
This is the big one. With nothing but water coming out the tailpipe, hydrogen cars should prove to be enormously beneficial to air quality and atmospheric carbon levels. As the seven billion people currently inhabiting this planet continue to make babies, finding a way to move everyone around without creating dirty clouds of poisonous gasses should be something everyone is interested in, from vegan yoga instructors to Jeremy Clarkson. Ok, maybe not Clarkson. Urban centers in particular, once blanketed by foul, harmful discharges, will start to breathe a little easier.
Hydrogen Is Everywhere
Instead of waiting around millions of years for decaying biomaterial to coalesce into petroleum, you can pull hydrogen from a variety of sources. And while the majority of H2 is currently created from natural gas — a fossil fuel — the fact that water and algae are also viable sources should speak to the immense possibilities of this technology.
Internal combustion engines have their benefits. The symphony of an Aston Martin V-12 comes to mind. However, as insanely awesome as that sound is, with all its burbles and crackling, it represents a lot of wasted energy. In fact, the most efficient ICEs out there only utilize about 25 percent of the energy released to move the car. By comparison, hydrogen fuel cells can get up to 85 percent efficiency. Suck it, Prius.
We all know what happens when there’s an oil spill, and it isn’t good. Whether it’s in your garage or the Gulf of Mexico, cleanup is a nightmare. Hydrogen, by comparison, is completely non-toxic. The gas is so light, it disperses rapidly into the atmosphere in the event of a leak. Should H2 fuel accidently find its way into your local environment, the flora and fauna won’t even notice.
Minimal Refuel Time
While EVs take hours to reach maximum charge (possibly even half a day if drawing from the wrong kind of outlet), the procedure for filling up a hydrogen car is familiar and fast. It’s as simple as putting a hose into a tank. After a few minutes, you disconnect and drive away, once again carrying enough fuel to go a range of several hundred miles.
Despite a plethora of methods to extract and refine hydrogen fuel, the process is far from perfect. There are even some reports that state it it’s doing more harm than good. And with the majority of our hydrogen coming from natural gas, it’s difficult to tout it as a solution to our reliance on fossil fuels. Until an effective alternative is developed, one that can outpace current methodologies, hydrogen fuel production remains one of the technology’s major detractors.
Hydrogen is like the party boy of the periodic table. All it wants to do is get out there, mix it up with some other elements, make a few molecules, and possibly light something on fire.
I’ll explain. Since hydrogen has such a low volumetric energy density, it takes a really big container of the stuff to compete with the range of an ICE. And when it comes to transportation, any component that adds girth and weight is considered bad. A bigger gas tank equals less interior room, bigger overall dimensions, and less efficiency. Additionally, the smallest leak will quickly liberate all the H2, transforming that big container into a big waste of space.
There’s another problem. Hydrogen is highly flammable; the smallest spark could ignite it. Compounding this is the fact that H2 gas is odorless and colorless, giving no warning of potential danger.
One of the trickiest parts of adopting a new fuel source is figuring out how to get it into the hands to those who need it. For traditional, petrol-powered vehicles, we have gas stations lining the highways and byways pretty much everywhere. But hydrogen is going to take major investment to get anywhere close to similar levels of accessibility.
Some carmakers are actively confronting the issue. Toyota and Honda are both investing millions to build hydrogen-refueling stations in California and on the east coast. However, it’s going to take a lot more to reach the ideal of driving from LA to New York on hydrogen power alone.
While water vapor is considered a greenhouse gas, the extent to which it can warm the planet has been the subject of debate. One study says that it can actually double the effects of increasing carbon dioxide levels.
Once considered a “zero-emissions” solution, hydrogen fuel may ultimately turn out to be just as harmful. The effect of millions of hydrogen-powered vehicles on the road has yet to be studied, and should water vapor prove to be a serious concern, the technology will have to evolve once again.
As is the case with most new and rapidly developing technologies, hydrogen power is expensive. From extracting the fuel to building the cell stacks, to actually manufacturing the car, nothing about it is cheap. For example, the Toyota Mirai, one of the most popular hydrogen cars available, is $60,000. That’s an awfully large sum for what basically amounts to a Camry (albeit a Camry powered by hydrogen). Toyota says it’ll pay for three years of fill-ups, which helps offset the sticker price a little bit, but not enough for anyone looking to save a buck (especially at current gas prices).
Despite its many drawbacks, hydrogen power remains quite promising. However, it’s nowhere close to widespread use. Fuel production remains expensive and environmentally questionable. The infrastructure is still in its infancy. Fuel storage technology has made big gains, and is now basically no more dangerous than gasoline, but there’s still room for improvement.
However, I believe these are all issues characteristic of a transformative technology undergoing rapid growing pains. Fuel extraction will advance, storage solutions will progress, and the prices will start to drop. There are already hydrogen-powered commuters and hydrogen-powered race cars. Infrastructure growth is bound to mirror popularity. In 20 years, hydrogen power will be commonplace.
While it’s far from perfect, the benefits of hydrogen power place it as the most viable next step beyond fossil fuels. The drawbacks, while numerous, are all relatively manageable. And in terms of meeting the world’s energy needs, it’s nearly impossible to find anything better.