Dude, Where’s My Hydrogen-Powered Car?
With zero-carbon emissions, hydrogen was supposed to be an energy cure-all. So why aren’t we filling up our cars with it?
4 min
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If this were a party, and you sat down and asked, “Why not hydrogen-powered cars?” you could be in for a long night. May I get you an espresso?
I get this question a lot. People wonder, given the current limits of battery technology, whether a hydrogen-powered car, using a fuel cell device to convert compressed hydrogen into electricity, would have longer range and quicker refill/recharge times.
Yes, if first you have the hydrogen. Preferably liquid hydrogen.
People assume hydrogen is abundant. It isn’t—not in a readily usable form. Atomic hydrogen bonds tightly to whatever is around. In the case of hydrocarbons, hydrogen has a death grip on compounds of carbon; in the case of water, it doesn’t want to quit oxygen.
Hydrogen is liberated from water in a process called electrolysis, using electricity to break its bond with oxygen. To separate H2 from fossil fuels—typically, natural gas, or methane—the process is called steam reforming. Neither is particularly efficient. Electrolysis can reach an energy efficiency up to 80% using best practices. That means it takes 50-55 kWh of energy—and associated emissions—to liberate 40 kWhs worth of “zero-emission” hydrogen.
Steam-methane reforming is about as efficient but the process produces intense carbon emissions, several times the hydrogen extracted, depending on the feedstock. It also requires a non-trivial sum of energy to compress H2 into a storage device—a hydrogen tank—so it might be used in an automobile.
Once on board, hydrogen’s ROI takes another hit at the fuel cell, a stack of permeable membranes where hydrogen is married with oxygen to produce water and electricity. The most efficient such devices yield about 60% of the potential energy, which knocks the system’s well-to-wheel efficiency down to 30-40%, comparable to that of a typical internal-combustion vehicle.
All of which is to suggest why, if your national energy policy aim is lower carbon emissions per unit of economic activity, hydrogen-based transportation has a hard time scaling.
How’s that coffee? Ready for another?
But even if zero-carbon hydrogen flowed like honey from the rock, it would be difficult to transport and deliver to millions of automobiles on a retail basis. Take pipelines: The infrastructure the oil-and-gas sector uses to move natural gas (methane) cannot readily be shared with compressed hydrogen.
Or fueling stations: The costs of the few publicly accessible H2 fueling stations that have been built in the last decade (there are currently 48 public H2 stations in the U.S., 47 in California and one in Hawaii) have been many times higher than those associated with conventional gas stations. These costs typically include a natural-gas reformer on site, avoiding the necessity of aforementioned pipelines and high capacity tanks. They also reflect the costs of compliance with federal, state and local regulations having to do with letting granddad pump his own high-pressure space fuel. Somebody at the city council meeting yells Hindenburg in three, two, one…
Hydrogen does have some lovely physical properties. Chief among them is high energy density by mass. A kilo of hydrogen embodies about three times the energy content (120MJ/kg) as a kilo of gasoline (44 MJ/kg, equivalent to six properly fused Molotov cocktails).
On that account, hydrogen mops the floor with the best lithium batteries. Tesla’s new 4680 cells may pencil out to, at best, 300 Wh/kg. The most energy-dense solid-state batteries on the horizon might deliver two to three times more. It still sums to less than 1kWh per kilogram, a fraction of hydrogen’s energy-carrying capacity.
And yet, outside of a few small-scale projects and compliance cars such as the Toyota Mirai, the entire automotive world is turning to batteries. Why?
In light vehicles, hydrogen’s limiting factor has always been its low energy density by volume—the size of the bottles, in other words. A typical automotive-grade pressure vessel might be a cylinder three feet long and one foot in diameter, nominally (3:1 ratio), heavily overwrapped with carbon-fiber reinforcement and pressurized to 350-700 bar. Such a bottle holds a precious 5.6 kg of H2, worth about 185 kWh.
However, again taking into account the losses at the fuel cell, the effective capacity is more like 111 kWh, comparable to current and conventional lithium battery technology. In this way hydrogen has a range problem too.
The thing is, if you need to move energy in bulk, or just move bulk, H2 is your friend. Test fleets of fuel-cell-powered heavy trucks are already on the road, as well as locomotives, ships, buses, and other applications where dimensional space isn’t quite so dear as in light vehicles.
Hydrogen could play a role in EV-charging infrastructure, especially in remote or delicate areas where wise policy would avoid generators, power lines and substations. Imagine an H2/EV station set up outside a national park, quietly producing electricity with a stationary fuel cell, using truck-delivered H2. “Compressed hydrogen is really a way to truck electricity around,” said David Reichmuth, senior engineer with the Union of Concerned Scientists.
Or you know what would be really cool? Liquid hydrogen (LH2), stored at -253 C. One cubic meter of cryogenic hydrogen represents about 2,343 kWh worth of energy, roughly equivalent to the stored energy of 23 fully charged Teslas.
And yet I know of only one effort to exploit cryo-hydrogen’s potential on four wheels: the Glickenhaus HFC Pickup. The work of Scuderia Cameron Glickenhaus (SCG) in Sleepy Hollow, N.Y., the HFC Pickup will be battle-tested in a future Baja 1000 off-road race, possibly using swappable tanks of liquid hydrogen to refuel on course.
And you thought it was hard to keep the beer cool.
Reprinted by permission of The Wall Street Journal, Copyright 2021 Dow Jones & Company. Inc. All Rights Reserved Worldwide. Original date of publication: February 10, 2022.
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Passwords aren’t enough to fend off hackers; these dongles are the best defense
4 min
Strong passwords are very important, but they’re not enough to protect you from cybercriminals.
Passwords can be leaked or guessed. The key to online security is protecting your account with a strong secondary measure, typically a single-use code. This is referred to as “two-factor authentication,” or 2FA, as the nerds know it.
I’ve written about all the different types of 2FA, such as getting those codes sent via text message or generated in an authenticator app. Having any kind of second factor is better than none at all, but physical security keys—little dongles that you plug into a USB port or tap on your phone during account logins—offer the highest level of protection.
Security keys have been around for over a decade, but now they’re in the spotlight: Apple recently introduced support for them as an optional, added protection for Apple ID accounts. Last month, Twitter removed text-message-based authentication as an option for nonpaying users, recommending instead an authenticator app or security key.
Some people are hesitant to use security keys because carrying around a physical object seems burdensome and they come with a $30-and-up added cost. Plus, what happens if they get lost?
I’ve used security keys since 2016 and think they are actually easier to manage than codes—especially with accounts that don’t require frequent logins. They’re not only convenient, but they can’t be copied or faked by hackers, so they’re safer, too.
Here’s how to weigh the benefits and common concerns of adding one or two of these to your keychain.
Which security key should I use?
Many internet services support the use of security keys, and you can use the same security key to unlock accounts on many different services. I recommend two from industry leader Yubico:
- YubiKey 5C NFC ($US55) if you have a USB-C laptop or tablet
- YubiKey 5 NFC ($US50) for devices with older USB ports
Other options include Google’s Titan security keys ($30 and up). In addition to working with laptops and tablets with USB ports, these keys are compatible with smartphones that have NFC wireless. Most smartphones these days have that, since it’s the technology behind wireless payments such as Apple Pay.
Adam Marrè, chief information security officer at cybersecurity firm Arctic Wolf, recommends that your chosen key is certified by the FIDO Alliance, which governs the standards of these devices.
How do security keys work?
To add a key, look in the security settings of your major accounts (Facebook, Twitter, Google, etc.). During setup, it will prompt you to insert the key into your laptop or tablet’s port or hold the key close to your phone for wireless contact.
Apple requires you to add two security keys to your Apple ID account, in case you lose one.
Typically, when you log in, you just go to the app or website where you’ve set up a key, enter your username and password as usual, then once again insert the key into the device or hold it close. (Some keys have a metal tab you have to press to activate.) At that point, the service should let you right in.
Why are they so secure?
Getting those two-factor login codes via text message is convenient, but if you are someone criminals are targeting, you could be the victim of SIM swapping. That’s where thieves convince carriers to port your number to a new phone in their possession, and they use it along with your stolen password to hack your accounts.
Even if they don’t go to all that trouble, criminals might try to trick you to hand them your codes, by calling you or spoofing a website you typically visit. At that point they can use the code for about 60 seconds to try to break in, said Ryan Noon, chief executive at security firm Material Security.
Security keys protect you in two ways: First, there’s no code to steal, and second, they use a security protocol to verify the website’s domain during login, so they won’t work on fake sites.
You can also add an authenticator app such as Authy to your most important accounts, to use only as a backup. But once you add these secure methods, you should consider removing the text-message code option.
In the rare case that someone snoops your passcode then steals your iPhone, beware: The perpetrator could still make Apple ID account changes using only the passcode, and even remove security keys from your account.
What happens if you lose your key?
The most important rule of security keys is to buy an extra one (or two).
“Think of your security key as you would a house or car key,” said Derek Hanson, Yubico’s vice president of solutions architecture. “It’s always recommended that you have a spare.”
If you lose a security key, remove it from your accounts immediately. You should have already registered your spare or an authenticator app as a backup to use in the meantime.
Where can you use a security key?
Start with your most valuable accounts: Google, Apple, Microsoft, your password manager, your social–media accounts and your government accounts.
When it comes to financial institutions, many banks don’t offer security-key protection as an option, though most leading crypto exchanges do.
What comes after security keys?
Security professionals and tech companies widely agree that passkeys are the future. They’re a new type of software option that combines the high security of a physical key with the convenience of biometrics such as your face or fingerprints. Passkeys are supported across the Android, iOS, Mac and Windows platforms, and some of your favourite sites already let you use them.
You can create a passkey on Facebook in security settings by following the app’s instructions under the security-key option. Dropbox has a similar passkey setup. Once you’re done, you’ll use your face or fingerprint as a second factor, instead of a code or key.
Eventually, physical security keys could be what we keep safe in strong boxes, as backups for our biometric-enabled passkeys. Even then, you’re probably going to want to have spares.
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