Hydrogen fuel cell technology

So what is a fuel cell? In simple terms, a fuel cell is a device that can use a combination of oxygen and hydrogen to create electricity. Polymer Electrolyte Membrane (PEM) fuel cells are currently the most common versions used for transportation. A PEM fuel cell contains a set of electrodes (an anode and a cathode) and an electrolyte, much like a typical battery. Unlike a battery however, the anode and cathode are separated by the PEM. To create electricity in a fuel cell, hydrogen gas is introduced. The hydrogen flows through a series of channels to the anode, where it reacts with a catalyst. The catalytic reaction causes the hydrogen to ionize. This means it separates the hydrogen molecule from the attached electrons. The result is a positively charged hydrogen molecule and negatively charged “free” electrons. The PEM that separates the anode from the cathode will only allow the positively charged hydrogen molecules to pass through. As a result of this selective passage, the electrons are left behind on the anode. The electrons develop a negative charge on the anode and the lack of electrons at the cathode (caused by the accumulation of the positively ionized hydrogen molecules) develops a positive charge. This charge difference should sound vaguely familiar as it’s very similar to the negative and positive terminals on a battery. As with a battery, if a circuit is provided to connect the negative and positively charged electrodes, electrical current will flow. In essence, a hydrogen fuel cell is a generator with no moving parts. The fuel for the generator is hydrogen and the exhaust emissions are limited to water vapor (H₂O). 

Hydrogen fuel cell vehicles have been in the press a lot in recent years. This may leave you wondering how many fuel cell vehicles are currently being sold in the United States, and what impact that may have on your future business. Currently, there are really only two fuel cell vehicles that are relevant to this discussion. Those two vehicles are the Hyundai Tucson Fuel Cell (introduced in 2014) and the Toyota Mirai (which, at press time, was planned for release in very late 2015).

While the Hyundai Tucson Fuel Cell is marketed as the first “mass produced” fuel cell vehicle, it’s very limited in availability. In fact, you can’t even buy this vehicle in the United States if you wanted to. Currently, the Tucson Fuel Cell is limited to three-year, 36,000-mile leases with no option to purchase. Even given those limitations, the bragging rights for this vehicle is that Hyundai has delivered over 75 (no that’s not a misprint!) in the US through September 2015.  That’s not exactly a number that would make you scramble to get ready for them in your shop, especially since they’ll be under warranty throughout their lease!

The Toyota Mirai will change things slightly. It appears this will be the very first hydrogen fuel cell vehicle to actually be sold (versus leased) within the United States. That being said, the area potentially impacted will still be very small. These vehicle sales will likely be limited to the Southern California area (as has been the case with current leases) due to the current hydrogen fueling infrastructure and incentives for the automotive manufactures.

So why the discussion?
You may be wondering why you should care about fuel cell vehicles if you’re unlikely to see them in your shop in the foreseeable future. It is not the fuel cell vehicles — at least not yet — that you should care about, but rather the technology in these fuel cell vehicles. From a practical standpoint the battery, electric machine(s) and inverter technology used in fuel cell vehicles isn’t much different than that used in current hybrid and fully electric vehicles. If you haven’t yet embraced hybrid/electric vehicle technology, you are, quite frankly, falling further behind every day. According to the Alternative Fuels Data Center, there were 73 hybrid and/or electric models offered for the 2015 model year. That’s an increase from just eight models in 2005, which is over an 800 percent increase!

Let’s take a look the Toyota Mirai fuel cell vehicle for a comparison of technology. This is essentially an electric vehicle with an onboard generator in the form of a hydrogen fuel cell. I was surprised to find out just how much of the technology in this vehicle is a carry-over from existing Toyota/Lexus hybrid vehicles. So what is being carried over?

·      High voltage battery: The high voltage battery in the Mirai is a 244.8V NiMh battery. Toyota describes this as “an existing design” from a Toyota hybrid model. This battery consists of 34 modules, each rated at 7.2 volts. For those of you already familiar with hybrid technology, this should ring a bell as those are the same specifications listed for a Toyota Camry hybrid.

·      Electric Motor/Generator: Toyota states, “we chose an existing motor from one of our Lexus hybrid vehicles, providing a history of reliability and reducing overall cost.”  While this component is more difficult to directly correlate to an existing make/model, the re-use of existing technology further highlights the ability to use existing diagnostic processes.

·      Power Control Unit (PCU): While this unit appears to be unique to the Mirai, Toyota specifically states that it is based on the PCU found in the Prius.

·      Inverter/Converter: Again, this unit appears to be unique to the Mirai with similarities to existing Toyota/Lexus hybrids.  The unit is listed as a 4-phase boost converter allowing the battery voltage to be stepped up to approximately 650V.  Much like the Prius (and other Toyota/Lexus models) this boosted voltage allows more power to be delivered from the electric machine when under peak demand.

So, what does all of this mean for shops looking to prepare for the future? To start, your technicians need training, but not for hydrogen fuel cell vehicles (at least not yet). The hydrogen fuel cell related training I’d consider relevant at this time is for the electric drive system. While the hydrogen system is interesting and makes great headlines with 10,000 PSI storage tanks and water as the only emission, getting training on that simply isn’t practical. These vehicles will likely be very limited in number and will be under warranty for the foreseeable future. In fact, for the “lease only” vehicles, they will NEVER be out of warranty. That means by the time you will see these vehicles in your shop (if you ever do), the hydrogen-related systems are likely to look much different than they do today. The electric drive portion, however, is relevant today because of the connections to hybrid and electric vehicles. 

Your action plan
At a minimum, your technicians should receive high voltage systems safety training. Limiting training to that level, however, significantly reduces your shop’s potential. I’d recommend going well beyond the basic safety training. In fact, I’d even recommend going well beyond the OEM training provided for hybrid and electric vehicles. To really prepare for the future, you should look into getting your technicians trained on the two major electric components that are most likely to experience problems — high voltage batteries and electric machines (motor/generators).  These are both components that are destined to eventual failure due to normal wear and tear.  Equipping your technicians with the knowledge and equipment to accurately diagnose these components both at the gross failure stage and ideally at the early/intermittent failure stage will help set up your shop for long-term success and will likely help set you apart from the dealership. In addition, you need to consider training your service advisors/managers on these vehicles to ensure they have the knowledge to explain the problems and related repairs to your customers.

The last thing I’d recommend considering when it comes to the potential for servicing hydrogen fuel cell vehicles is your facility. While there isn’t a reason to start planning renovations today to accommodate vehicles you’re unlikely to see tomorrow, it is something you should keep in the back of your mind. The biggest thing to consider is that current repair facilities are virtually all set up to handle fuels that are heavier than air. If you look around your shop, you’ll notice that all potential ignition sources are at least 18 inches from the ground (provided your facility is up to code). This was done because gasoline vapors can collect at the ground level. When looking at fuels such as hydrogen, however, this scenario changes. Hydrogen is actually the lightest element in the periodic table. This means that if hydrogen was to leak from a vehicle in a service facility it would accumulate near the ceiling, not the ground. So, walk out into your shop and look up at the ceiling. Do you see anything within 18 inches of the ceiling that could serve as an ignition source? Anything such as a light fixture, heater, fan, even a junction box could be a danger. 

Of course, you’re probably thinking with the limited number of hydrogen fuel cell vehicles likely to be seen in the aftermarket this consideration isn’t worth worrying about. Keep in mind there are other fuels that are also lighter than air. One such fuel that has been making a comeback lately is Compressed Natural Gas (CNG). Much like hydrogen, a leak from a CNG-fueled vehicle can cause fuel to accumulate near the ceiling rather than at the floor. Depending on the level of service being done on these vehicles (hydrogen or CNG), whether vehicles are stored inside overnight, etc. the facility requirements change. If you are considering a new facility or a major renovation/expansion of your current facility, this may be something you want to keep in mind during the planning process. Be prepared as the required modifications may include a significant expense. However, the alternative of servicing these vehicles without the proper modifications may expose you to significant liability.

The future of hydrogen fuel cell vehicles and the potential impact they will have on the aftermarket repair industry is still somewhat uncertain. Change within our industry, however, is virtually guaranteed and everyone will need to adapt to avoid becoming obsolete. Just try to avoid being distracted by the media hype when making your plans.