Dec 252014
 
Toyota's new hydrogen fuel cell powered vehicle, the Mirai.

Toyota’s new hydrogen fuel cell powered vehicle, the Mirai.

The last year or two has been full of exciting developments with battery powered electric vehicles (BEV), and the concept of BEV seems to have ‘sucked all the oxygen’ out of the alternative fuels discussion.

But the less well known hydrogen powered fuel cell electric vehicles (FCV) have slowly been evolving, and 2015 sees the promised release of an almost mainstream vehicle by Toyota, its Mirai, expected to sell for around $57.500.  The following year, Honda intends to also release a FCV.

Clearly both Toyota and Honda are auto manufacturers of unassailable size, strength, and sense, and if they are developing FCV autos, that would seem to anoint the technology with a high degree of credibility.  Should we all stop pining for a Tesla BEV and instead start saving up for a FCV?  If nothing else, the Mirai is substantially less expensive than a Tesla (which quickly climbs up in price to around the $90,000 mark).

Let’s take a careful look at the technology and reality of hydrogen powered fuel cell vehicles.

The Upside of Hydrogen Powered Fuel Cell Vehicles

A fuel cell is different to a regular internal combustion engine (ICE).  As you know, an ICE explosively burns some type of fuel inside cylinders, converting the force of each tiny explosion into rotary motion and powering the vehicle.

A fuel cell uses a catalyst to chemically combine hydrogen and oxygen (it takes the oxygen from the air around us, and hydogen from a fuel tank, the same as an ICE with its petrol and air) to form water and electricity.  It does this silently and smoothly, and the only by-product of the process is environmentally friendly pure water vapor, while the electricity is then harnessed to drive an electric motor to power the vehicle.

So, silent, smooth, and environmentally friendly.  So far, so good.  There’s a lot more to like about hydrogen power, too.

Hydrogen scores another bonus for being an abundant element.  While there’s vanishingly little of it free in the atmosphere (due to its light weight, the hydrogen tends to just rise up and up through the atmosphere and get lost into space), at least in theory, any time you need more hydrogen, all you need to do is electrolyze some water to separate it into hydrogen and oxygen.

And another bonus.  One of the current killer weaknesses of a battery powered electric vehicle is the time it takes to recharge the battery.  We’ve all become accustomed to pulling into a nearby gas station any time our gas gauge gets low, and within five or six minutes, we’ve stopped at a pump, used our credit card to authorize the charge, pumped the petrol, completed the transaction, and are ready to leave again, having pumped 10 – 20 gallons of fuel into the vehicle’s tank and added another 200 – 400 miles of driving range.

With a BEV, recharging the battery can take as many hours as pumping gas takes minutes – and sometimes even longer.  Plus, while you never have to wait more than a minute or two for a free pump at most gas stations, if you find cars already using an electric recharging station, you might have to wait hours until they’ve finished their recharging before you can even start your process.

Refilling a FCV’s hydrogen tank is only slightly more complicated than refilling your present car’s gas tank.  It takes about the same time, and you get about the same renewed range at the end of the process.

A FCV has less weight in its fuel cell and hydrogen tank than a BEV does with its rack of batteries (both types of vehicle use similar/identical electric motors).

Because a FCV can more conveniently store more fuel than a BEV, they are also better suited for types of vehicles that burn a lot of fuel due to their heavy weight or types of duty application.

So, there’s clearly a lot of positive upside to considering a FCV, right?  But, before you rush off to a Toyota dealership to order a new Mirai, please keep reading.

The Dismal Downside to Hydrogen Powered Fuel Cell Vehicles

Perhaps the biggest downside to a FCV is that the hydrogen is expensive.  A typical BEV can be equated to have a fuel cost similar to if you were paying about $1/gallon for gas.  But the cost of hydrogen for a FCV works out to about the same as paying $3 – $3.50/gallon for petrol.  Now, sure, today sees a happy but probably short term drop in gas prices down to somewhere in the mid two dollar a gallon range, but even when gas is at $3.50 a gallon as it was earlier this year, there’s no price benefit by switching to hydrogen, and possibly there might be some extra cost if you use hydrogen rather than gas.

Plus, states are increasingly shifting from not levying any type of road tax on electric vehicles to now seeking a way to get some compensation for not recovering income every time the vehicle is refueled, as happens ‘automatically’ with the taxes built into the pump price of petrol.

Furthermore, to be fair to BEV technology, while it is true that if you need to recharge your vehicle during a typical day’s usage, you have a time-consuming challenge on your hands, most BEV owners treat their cars like their cell phones.  They top them up each night at home, and have more than enough charge for the next day’s typical usage.  They never need to recharge during their normal day of driving, and if anything, the added convenience of simply recharging at home spares them the hassle of having to regularly detour to the gas station that is a part of operating a normal petrol powered vehicle.

One more thing about hydrogen.  The tank that holds the hydrogen is under extraordinary pressure – something like 10,000 pounds per square inch.  Yes, that’s 5 tons of pressure on every square inch of the storage bottle.  We don’t know of any bottles exploding, but you have to wonder about the potential for this in an accident, or when something on the road is flung up and into the underbelly of the car, or if the vehicle catches fire or is caught in a fire.

So, the good news is that refilling a hydrogen tank doesn’t take long.  But the bad news is that there are very few hydrogen refilling stations out there.  While you mightn’t see them, there are actually many thousands of electric recharge stations in the country (this source lists 8,827 in Dec 2014 and is an incomplete list based on our cross-referencing with other lists such as this), and more appearing all the time, and of course, few BEV owners need them anyway.

There’s also no way you can refill a hydrogen car at home, unless you invest not only in the expensive technology to manufacture hydrogen, but also in the even more expensive technology to compress and store it at 10,000+ psi – and even if you did these costly things, you’d probably have problems with permits and the fire marshal.

So with a hydrogen fueled vehicle, you definitely must have convenient access to a refilling station.  Unless you’re in some parts of California, you probably don’t have and possibly never will have one nearby.  There are about 50 in total in the US, 22 of which are in California.

The chicken and egg cycle for FCVs and their refilling stations is complicated by the fact that whereas it is cheap to add an electric recharge point (maybe $10,000 per charging point), it can cost $1 – 2 million to construct a hydrogen refilling station.  That’s a huge barrier to entry.  To put it another way, it costs about 100 times more to establish a hydrogen filling point than an electric recharge point.

One more thing about hydrogen.  Although ‘burning’ the hydrogen through a fuel cell is environmentally friendly, creating the hydrogen in the first place is not so environmentally friendly.  You’re either using large amounts of electricity and/or you’re using chemical processes that involve processing methane and other gases, and both involve carbon releases and consuming finite natural resources.

A vehicle using FCV technology requires about 2.5 times as much source energy to power it as does a BEV.  No matter how clean the power being used, that’s just plain wasteful.

Lastly, those hydrogen fuel tanks are heavy.  While a FCV weighs less than a BEV with a large battery pack (such as a Tesla) it weighs more than comparable ‘regular’ internal combustion petrol-powered vehicles.

Now for the fuel cell itself.  These operate best within a fairly narrow range of power outputs.  There’s a maximum power they can produce, an optimum power level fairly close to the maximum, and if they operate much lower than that, their efficiency starts to drop off.

What that means in a vehicle is that it will be massively underpowered.  The fuel cell will be designed to provide enough power to keep the vehicle moving normally in normal conditions, and with a bit of reserve power for starting and accelerating.  But if you’re trying to overtake, you’ll need much more distance, and if you’re going up a steep hill with a fully loaded vehicle, be sure to pull far over to the right in the slow lane and let the trucks zoom on by.

Will Things Improve in the Future?

Hopefully you see the preceding section as a damning indictment on the current status of hydrogen powered fuel cells.  But surely it is a new technology and with refinements, will get very much better?

Not necessarily.  The chemical and electrical processes to create hydrogen use mature technology, and while there are probably some minor improvements and enhancements, underlying chemical and electrical laws limit the upside to such things.

Perhaps electricity costs will come down, but if that unlikely event occurs, the benefit of lower electricity costs will flow directly through to BEV technology as well as FCV technology.  And we don’t see any sudden drop in electricity costs at all – if anything, the growing drain on our electrical generating system and distribution grid caused by increased numbers of BEVs is likely to put pressure on electricity prices and at best keep them stable and at worst see them increase.

Don’t expect renewable energy to result in lower cost energy.  Both wind and solar power generally ends up costing more than electricity generated from nuclear power, natural gas, oil, or coal.  Again, if anything, the growing amount of renewable energy, while possibly benefitting the planet, will see our energy costs rise rather than reduce.

It is probable we’ll see more hydrogen refilling stations appear, but it is also probable we’ll see better/faster battery recharging technology, plus longer range batteries that reduce the need for away-from-home recharging, with the net result the one possible current weakness of the BEV technology will be reduced.

Currently, if we look at the price differential between a Toyota Mirai ($57,500), a Chevy Volt ($34,400), a Nissan Leaf ($29,000 – $35,120) and a Tesla S ($70,000 and up), the Mirai is clearly less expensive than the Tesla and clearly more expensive than the other two popular BEVs.  But Tesla is projecting the release of its Model III in several years and says it will be about half the price of present Model S cars – this price drop being anticipated as a result of Tesla’s new battery factory that will halve the cost of the batteries, and general production efficiencies as its production ramps up with more economies of scale.  The generally accepted expectation that batteries will halve in cost will see reductions in the price of other BEVs too of course.

There will probably be reductions in the cost of fuel cell power generators, too.  But, it would seem that a FPV might remain appreciably more expensive than a BEV to purchase up-front, and driving the underpowered FPV car will use hydrogen at three times the cost of electricity in the sporty BEV.  We’re also not sure about how maintenance-intensive the fuel cell itself may prove and what the cost of repairs will be, while the batteries in a BEV are showing themselves to be ultra-reliable and longer lived than originally projected.

Summary

Do we really need to spell it out?  The superficial ‘benefits’ of hydrogen powered fuel cells are massively outweighed by their downsides.  And even if many of these downsides can be improved upon over time, the stark reality remains that in terms of total energy required (ie considering the energy costs of creating the fuel as well as the energy efficiencies in using it) battery power is two or more times more efficient than fuel cell power.

Here’s a review of the Mirai, and a good article with more detail on the points we make.

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