These days, when we think about the advances in transportation technology in the automobile or aerospace industries, we tend to think of the reality of semi-autonomous cars or the potential of our drive to get to Mars. The images we conjure are romantic – intrepid explorers facing the desolation of an unknown planet, starting afresh in a new Eden without limits. Or whimsical – the convenience of vehicles that drive themselves to where we need to go, safely and conveniently, always at our beck and call. But what we don’t tend to consider so often is the means we still need to develop and standardize in order to power these endeavors. You’d have to be living in almost complete isolation to be unaware of the finite nature of our current fossil fuels and, more importantly, that we are rapidly approaching a time when the well will run dry – figuratively and literally. Indeed according to Millennium Alliance for Humanity and the Biosphere (MAHB), a platform addressing the environmental threats facing the planet, supplies of oil will be exhausted by 2052, gas production will end in 2060, and coal will cease to be mined by 2090.(1) And when that happens, transportation as we currently know it will grind to a very permanent half. No planes, trains, or automobiles. Not even those 4 stroke gas-powered bicycles that are fast becoming so very popular. Nope, when the supplies run out, we’ll be back to peddling like fury or hopping on Shanks’s pony – aka walking.
Or will we? It sounds like the end of the world, and it would be – at least as we currently know it. Without global transportation we can say goodbye to most of our infrastructure – from global travel to national security and emergency services to food delivery supply chains. The dissolution of civil society is all too easy to imagine. And this is why we are, as a society, increasingly looking to alternate methods of powering our world. From environmentally friendly options such as wind, wave, and solar to next generation nuclear power, the search has begun in earnest to research other options. And some powerful names are doing more than simply consider the options: they are investing in them. And, perhaps fortunately, the key players have very different ideas as to the shape of the next generation of fuels. Let’s take a closer look…
For Toyota, the watchword is Mirai – the Japanese for ‘future.’
In an interview with Design News, a resource for the design engineering community, Toyota engineer Jackie Birdsall hinted at exciting developments in several areas of automotive technology: ‘Things that were originally said to be impossible have been achieved. There’ve been these incremental steps that I think aren’t visible to the public, but as far as engineering achievement are really spectacular.’(2) Birdsall came to the field as a lover of ‘muscle cars,’ large vehicles with a powerful V8 engine that were originally designed for drag racing. Understanding that her passion for these gas-guzzling behemoths was not aligned with her environmental sensibilities, Birdsall pivoted to focus on zero emission powertrains, interning with DaimlerChrysler RTNA (Research and Technology North America) in Sacramento, CA. She is currently working on the compressed hydrogen storage system which, just as it sounds, stores the gas for use as fuel under compression. How does it work? Hydrogen is pumped into a vehicle and is stored in a carbon-fiber reinforced fuel tank. Grills on the front of the vehicle allow air to reach the fuel cell stack which allows the hydrogen to react with the incoming oxygen to create electrical energy. Hitting the ‘gas pedal’ sends power from the fuel stack to the motor to propel the car. In contrast with the exhaust gases emitted from traditional vehicles, the only by-product of a hydrogen fuel cell car (HFC) is water.(3)
Interesting, but when have we seen this type of gaseous fuel storage fail?
Most famously perhaps, in the flight of Apollo 13 when a warning was triggered by a drop in hydrogen pressure in tank #1. According to the chronology of the incident detailed by the NASA Space Science Data Coordinated Archive (NSSDCA), the lowering of hydrogen pressure led to a similar situation in oxygen tanks #1 and #2 leading to a loss of all O2 stores, water, electrical power, and propulsion.(4) Houston, there was a problem indeed.
So what would happen if Birdsall’s hydrogen storage system failed while it was powering a regular car? Nothing quite so dramatic, she says: ‘All the tanks are designed to do what is called “Leak Before Burst,” LBB. Which means it releases the hydrogen in a controlled way so that the tank doesn’t rupture.’(5) And the tanks are rated to 70 megapascals or 10,000 pounds/square inch (psi). (To put this in context, the air in scuba diving tanks is compressed to between 2600 psi on the lower end and 3500 psi at the upper end of the scale.) And to verify the safety of the LBB, Birdsall’s team uses a high strain rate impact test which consists of shooting a bullet into the side wall of the tank and measuring the controlled pressure drop.
But how is the hydrogen sourced?
As one of the most common elements, hydrogen can be derived via the steam reforming of methane – a common by-product of the deterioration of landfill matter. In gasification, another popular method of extraction, organic matter is heated to a high temperature which allows the hydrogen to separate out for storage. And, in addition, electrolysis is a relatively simple process in which the H of H2O is released by passing an electrical current through water. As Toyota notes: ‘Hydrogen is lighter than air and incredibly pure. When used in a fuel cell, it is highly efficient and leaves no carbon emissions behind. And best of all, it’s virtually everywhere.’(6)
With that in mind, Toyota is not the only manufacturer sufficiently interested in fuel cell technology to invest heavily in it. The Daimler Benz organization, creator of the Mercedes-Benz for instance, commissioned a purpose-built cleanroom to produce fuel cell technology. Based in Vancouver, British Columbia, the 3.3K square meter facility is home to an ISO 8 cleanroom, fuel cell stack assembly area, and liquid injection molding room and set the corporation back a whopping $4.5 million.(7) Moreover, in 2017 General Motors partnered with Honda Motor Co. to build fuel cell stacks for green vehicles in a facility near Detroit, MI. Known as the birthplace of the modern American automotive industry, Michigan was selected to be the ‘epicenter of the hydrogen fuel infrastructure and vehicle sector’ according to a report in CALSTART, a non-profit consortium dedicated to promoting a clean transportation modality.(8) In a round table event attended by manufacturers, industry leaders, the US military, state representatives, and local influencers, the ‘economic, national security, air quality and environmental benefits of developing vehicles fueled by and infrastructure to deliver the zero-emission fuel’ were emphasized. (9) But additionally, the economic impact in terms of employment was also at the forefront of participants’ minds as noted by Pat Valente of the Ohio Fuel Cell Coalition: ‘Designing, developing and adopting hydrogen vehicles and a hydrogen infrastructure means we will benefit economically, environmentally, and in the creation of new jobs.’(10)
However, although the creation of jobs can only have a positive impact on a state in sore need of economic stimulus, the adoption of fuel cell technology has its detractors nonetheless. One of whom is pretty well known in the tech innovation arena: Elon Musk. Quoted as calling hydrogen fuel cells ‘fool cells,’ Musk derided their use as ‘mind-bogglingly stupid,’ claiming that successful adoption is ‘simply not possible.’(11) But why? According to skeptics like Musk, hydrogen fuel cell powered vehicles are unnecessary given that battery electric vehicles (BEV) already do the same job. An HFC is essentially a battery-powered car, albeit with a smaller – and therefore less powerful – unit. As noted above, in order to run, fuel is stored aboard the vehicle to charge the battery instead of using a reciprocating engine (like the BEV). In effect, this puts a middle stage between the power (liquid hydrogen) and the charge (battery), adding not only a layer of complexity to the process but also a physical detriment to performance: a heavy-weight storage tank.
Moreover, when have you ever seen a hydrogen charging station?
Where our roadways and highways are littered with opportunities to refuel our vehicles with gas or diesel (and our road-tripping selves with chips and candy), the only other recharging station you’ll see to date is the occasional one dedicated to the electric car. If you live in California which, in 2018, boasted 4,978 charging stations, you’re likely to see them more frequently than, say, if you move to Alaska, which offered only 9 statewide.(12) But even that paltry number is significantly higher than that for hydrogen-power charging facilities.
So, given the lack of terrestrial infrastructure, it is perhaps more likely that hydrogen fuel cells will remain prominent solely in the aerospace realm, at least for the foreseeable future.
Toyota has also partnered with the Japanese Aerospace Exploration Agency (JAXA) to examine the feasibility of a manned, pressurized rover powered by hydrogen for use on the lunar surface. Accommodating two people (or up to four in an emergency) the rover would be approximately 13 cubic meters in size and would boast a ‘total lunar-surface cruising range of more than 10,000 km’ which is surely a sufficient range to be able to perform some serious exploration of the environment.(13) Moreover, these types of vehicle would not only support the unmanned missions already planned for the Moon and to Mars but also further the progress being made in potentially colonizing the Red Planet. As Koichi Wakata, Vice President of JAXA, notes in a Cleanroom Technology article, ‘We envision [manned, pressurised rovers] will take place in the 2030s. We aim at launching such a rover into space in 2029.’(14)
So whether we deploy the technology on our daily commute or in our outermost space exploration, it does look likely that HFCs will play a role in our future.
Whether innovators like Elon Musk choose to adopt it or not, the abundance of hydrogen and its simple conversion to fuel is a promising development in the face of dwindling supplies of our traditional natural resources. Almost everyone is in agreement that our exploitation of the environment cannot continue in the same way as it has since the Industrial Revolution and new sources of power must be found if we are to sustain our societies in the post fossil fuel era. We look forward to seeing how developments in this arena disrupt the paradigm and shape the landscape in the coming years.
Would you feel safe to drive a car powered by a hydrogen fuel cell? Are you more interested in a purely electric vehicle? Or will nothing dissuade you from a traditional source of locomotive power? We’d love to know your thoughts!