Have we lost you already in the eternal alternative fuels discussion? From gas to electric to hydrogen to natural gas \u2013 there are no shortages of powertrain options these days for those looking past diesel. But what we haven\u2019t talked a lot about is hydrogen. While everyone has been focused on electrification, hydrogen has been steadily making inroads. <\/p>\n\n\n\n
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Hydrogen offers an effective alternative to batteries. You\ncan \u201cfuel up\u201d faster and the storage medium and supporting infrastructure is\nlighter and more compact. Hydrogen can also be stored indefinitely with zero energy\nloss. And while hydrogen is a volatile gas, it is actually much safer than\npeople think. And when compared to lithium-ion, which can burn for days in the\nevent of a breach, hydrogen doesn\u2019t react that way.<\/p>\n\n\n\n
Hydrogen can also be renewably harvested from wind and solar\npower generation and can be created and used on site. It can also be made to\nscale and stored at commercial-scale production facilities and then transported\nsafely to where it is needed. And it doesn\u2019t need a heavy amount of\ninfrastructure. <\/p>\n\n\n\n
How Does it Work<\/strong><\/p>\n\n\n\n But the question is, how are hydrogen trucks powered? Put\nsimply, once on the truck, the hydrogen \u2013 which is in a gaseous state, enters\nthe fuel cell and recombines with oxygen pulled from ambient air. This air\nitself has flowed over a catalyst-lined membrane. In industry parlance, this is\ncalled an electrochemical transaction. The reaction itself produces an electron\nand the capturing of that electron produced power.<\/p>\n\n\n\n Of course, this is a huge oversimplification of what is\notherwise a very complex process taking place within the fuel cell. Yet, in the\nend, the byproduct is quite simple: water vapor. While most people would ask\nwhat is not to like about a power source emitting nothing but water vapor,\nhydrogen is not without its critics. <\/p>\n\n\n\n Critics say that the energy loss problems start at the\nproduction side. Consider the primary ways hydrogen is produced, through steam\nreforming of natural gas and electrolysis. Currently, 95% of all hydrogen used\nin commercial vehicles and other forms of production comes from steam reforming\nof natural gas, or methane. Electrolysis only accounts for about 4% of the\ntotal, according to the Department of Energy. <\/p>\n\n\n\n Problems with the Process<\/strong><\/p>\n\n\n\n The problem is with steam reforming. This process creates a\nhigh-temperature steam which produces hydrogen when combined with natural gas.\nWhile this is the least expensive way to produce hydrogen, it creates a wealth\nof greenhouse gas components, such as carbon monoxide and carbon dioxide. And\ndepending on the feedstock used in production, a ton of hydrogen could yield\nten tons of CO2. In the end, net energy yield from steam reforming is negative.\n<\/p>\n\n\n\n Conversely, electrolysis uses electricity to split water\nmolecules into two atoms of hydrogen and one oxygen atom. This form of capture\ncan be compressed and stored for future use. Yet, this method is not without\nits downsides. The process itself consumed 30% more energy than it produces.\nFortunately, there have been advances in materials engineering to increase\noverall efficiency.<\/p>\n\n\n\n Engineers and researchers have come up with something called\na Proton Exchange Membrane (PEM) electrolyzers. These devices use the same type\nof process utilized in a hydrogen fuel cell, but they do it backwards. As this\nprocess is further refined, many believe it could reach up to 80% efficiency\nbefore 2030.<\/p>\n\n\n\n Another issue lies in losses that occur when the hydrogen is\ncompressed. To put hydrogen into a state that makes transport and storage\neconomical, it must be compressed to between 5,000 and 10,000 psi, or it must\nbe cooled to around minus 425 degrees in liquid cryogenic tanker trucks. Not\nonly is this a huge process, but energy losses occur during these transitions. <\/p>\n\n\n\n Looking Past Efficiency and Batteries<\/strong><\/p>\n\n\n\n Still, it is important to note that efficiency is not the entire story. While some may think net energy loss may be a good reason to forget about hydrogen power, it is important to remember that efficiency isn\u2019t everything. Energy harvested from solar, wind, and other renewable sources cannot always be used at the moment they are produced. This all depends on local electric grid loads, of course. <\/p>\n\n\n\n <\/p>\n\n\n\n <\/p>\n\n\n\n Fortunately, excess renewable energy can be stored and used\nlater, even if the efficiency of the collection and consumption of the energy\nis not entire optimum. There is an argument to be said for charging batteries\nfrom the grid, however, as this method is much more energy efficient. <\/p>\n\n\n\n Batteries come with their own drawbacks. There are\nenvironmental and worker considerations related to mining the materials needed to\nmake batteries. There are also decommissioning concerns. What is the most\nenvironmentally conscious way to dispose of batteries? We all have heard and\nread about mountains of electronic waste in third-world countries. Are battery\ntechnologies destined for the same fate?<\/p>\n\n\n\n There are also significant downstream problems that come\nfrom battery power. The size and weight of batteries when compared to hydrogen\nstorage tanks is far, far heavier. Hydrogen tanks can also be refueled faster\nthan batteries. <\/p>\n\n\n\n Truckers waiting at an electric charging station may find\nthemselves spending an excessive amount of time waiting for their truck to\ncharge. Even fast-charge stations cannot match the time it takes to refuel with\nhydrogen or diesel. Compare 10 to 20 minutes to fill a hydrogen tank compared\nto a battery, which can take several hours, and there really is no comparison\non that front. <\/p>\n\n\n\n Fuel Cell Stack Optimization<\/strong><\/p>\n\n\n\n Hydrogen fuel cells are powered by fuel cell stacks, which\nis comprised of dozens of proton-exchange membrane fuel cells. You recall we\nreferred to PEM technologies earlier. PEM forms the basis of a fuel cell stack.\nSince a single hydrogen fuel cell produces a small amount of energy, the fuel\ncell is set up with stacks of these cells. When combined the output can be\nquite high. <\/p>\n\n\n\n Put together, around 400 fuel cells put together produces\naround 120 kilowatts. And while this may differ depending on the producer and\nmethodology, the eventual energy output is usually similar. Producers may use\ndifferent membranes or catalyst formations, or they may use a different\nreaction method, but in the end, it is still hydrogen power. <\/p>\n\n\n\n In the end, the more stacks you add, the higher your overall\nkilowatts will go. So, you must increase the stack output proportionally with\nthe number of fuel cells. Once fully assembled, the fuel cell can be further\noptimized by careful calibrating the amount of air that runs through the\nstacks. The cooling process also provides another opportunity to refine energy\ndensity. <\/p>\n\n\n\n Hydrogen power shares some similarities with diesel\npowerplants. Diesel engines require additional water pumps if you want to add\nmore cylinders or increase displacement. For hydrogen-powered variants, you\nwould simply increase the size of the water pump. Fuel cells do face the same\ntypes of problems battery makers do, such as available real estate on the\nvehicles. <\/p>\n\n\n\n Since OEMs want to fit fuel cells into the engine bay, fuel\ncell manufacturers have had to adjust the shape of their cells. Many have opted\nfor easily interoperable cube shapes. Modular fuel cells allow them to be\nstacked next to other vehicle components. Compact spaces allow for more real\nestate for other truck components. <\/p>\n\n\n\n The Future of Fuel Cells<\/strong><\/p>\n\n\n\n Even as we talk about the pros and cons of fuel cells and\nother energy generation methods, we have to acknowledge we are a long way off\nfrom seeing full-scale commercialization in big rigs and other commercial motor\nvehicles. Many OEMs are looking at 2021 as a year that the hydrogen industry\nbreaks out, but then again, many have been saying it was ready for a breakout\nfor a long time. <\/p>\n\n\n\n Still, full-scale hydrogen power for commercial motor vehicles is a tantalizing idea. Hydrogen is, after all, the most abundant element in the universe. We would certainly never want for a fuel source. It also occurs naturally in a compound form. And since water and hydrocarbons are among the world\u2019s most abundant sources of hydrogen, the key is to figure out an environmentally friendly and cost-effective method for extracting it and utilizing it as a fuel source. <\/p>\n\n\n\n <\/p>\n\n\n\n <\/p>\n\n\n\n Whatever happens, the carbon-free transportation supply\nchain is upon us. As the world emerges from the shadow of COVID-19 and looks\ntowards a renewable future \u2013 with states like California pressing the mandate \u2013\nalternative fuels like hydrogen will only become more and more commonplace. <\/p>\n","protected":false},"excerpt":{"rendered":"