“Hydrogen might prove to be the Heineken of clean energy: able to refresh the parts of an economy that electrification cannot reach”
-Economist, Issue July 4-10 2020
Hydrogen is one of the most widely discussed, intriguing topics in clean energy right now. What exactly is this element, how is it produced and how does it relate to our clean energy transition?
The Separation Challenge
Hydrogen is very abundant in nature, yet also not found on its own- it is combined with other elements such as water. Therefore in order to be used (for example as a clean fuel for vehicles), it first needs to be separated. There are a few ways to do this, but the most common three are below, which use different techniques to produce hydrogen.
1. Steam Reforming or Natural Gas Reforming (Grey Hydrogen)
- Currently the most common way to produce hydrogen, this technique begins with a liquid or gas that contains hydrogen like natural gas. This fuel then reacts with steam at high temperatures in a machine called a reformer, resulting in hydrogen, carbon monoxide and carbon dioxide (CO2).
- The CO2 is the catch; because CO2 is emitted in this technique, steam reforming is not all together climate-friendly, even if the resulting hydrogen is then used as, for instance, a clean transportation fuel. Carbon capture technology- if effective- can alleviate this issue- (“Blue Hydrogen”).
2. Coal Gasification (Black Hydrogen)
- Coal is a highly variable substance that can easily be converted to many products- including hydrogen. Coal is reacted with oxygen and steam under high temperature and pressure, and the resulting product is “synthetic gas”, primarily containing hydrogen and carbon monoxide. A second step involves reacting the carbon monoxide with steam to produce additional hydrogen, plus CO2.
- Like steam reforming, coal gasification is certainly not the ideal way to produce hydrogen, as it results in CO2 emissions. Even if it can be combined with carbon capture, government policy around hydrogen will likely- hopefully- dissuade gasification, and instead promote advancements in the cleanest way to produce hydrogen- through water.
3. Electrolysis (Green Hydrogen)
- Out of the three hydrogen production methods, electrolysis is by far the most climate-friendly. Electrolysis involves separating water into its two elements- hydrogen (H2) and oxygen (O2). A source of electricity is needed, which passes through water as an electrical current, to extract the hydrogen . What makes this process so clean is that the electricity can be sourced from renewable energy such as solar, wind or hydro.
- Unfortunately, electrolysis equipment remains expensive. However, with hydrogen now at the forefront of future clean energy policy in many countries, and with major players like BP and Orsted investing in this technology, electrolysis is sure to reach economies of scale as did wind and solar before it.
- For more on electrolysis, watch for my followup post called “Key Opportunities and Challenges of Green Hydrogen,” which will discuss why electrolysis is the key to hydrogen’s massive potential role in our clean energy transition.
How Green Hydrogen Could Be a Game-Changer for our Clean Energy Transition
“When advances are made, hydrogen can fill critical energy needs… transportation… heat and generate electricity for our homes. The future possibilities of this energy source are enormous.”Dan Lipinski
Hydrogen has become widely considered as an essential component of the decarbonization pathway for industrial nations. One of the reasons for this is that hydrogen has its use as not just one but many different technologies, in various sectors of the economy as we move away from fossil fuels. It can be used in place of fossil fuels in the power sector, in buildings, in industry, and in transportation both on-ground and aviation.
Electrolyzer manufacturer ITM Power notes that the current global market for hydrogen of all types is currently 70 million tons- however, only 1 million tons are used for energy and the rest as industrial feedstock. Yes as the International Energy Agency states in its new report,
“Governments and businesses are finally putting serious resources into the clean energy potential of hydrogen, which this report makes clear will be critical for reaching zero emissions.”IEA Energy Technology Perspectives, 2020
The IEA provides a very useful graph showing their estimates for global hydrogen demand between now and 2070, broken into demand by sector.
Hydrogen in general is one of my major interest areas, however I am most excited about hydrogen’s tremendous potential as fuel for long-haul trucking and medium/heavy duty transportation.
Fuelling Medium/Heavy Duty Transportation
Jurisdictions across the globe are making enormous strides when it comes to the share of electric vehicles (EVs) on their roads. Importantly, these strides do not take into account the significant social inequities that remain in accessing EVs (see my post on ideas for Pacific Power’s Blue Sky program for more). Nonetheless, two key factors make it very likely that not too far into the future you will leave for work in the morning and suddenly are hard pressed to spot a single gas engine on the road. One, government-mandated EV targets are on the rise, and not only in climate-progressive jurisdictions like California and British Columbia. A rising number of US States and Canadian provinces have targets to ensure that by a certain date, the sale of ICE (internal combustion or gas) vehicles will be slim to none against EVs. Two, although their upfront pricetags are still out of reach for many today, the cost to purchase an EV is falling by the year, and will only continue to drop as batteries become cheaper.
There is no doubt that the “EV Revolution” as some are calling it, is a tremendously positive sign of progress both for our air quality as well as climate change. And, in the long run, our pockets- which can breathe a sigh of relief no longer having to foot gas or maintenance bills. However, electrifying passenger vehicles is one thing. What about the much larger vehicles we see as soon as we merge onto a highway- long-haul trucks?
Hydrogen has huge potential as a fuel for long-haul trucking, which will be hard to electrify due to a key barrier- “energy density.” Almost all electric vehicles globally are powered by regular lithium ion batteries, the same batteries you find in all your portable electronics. However, lithium ion batteries have a low energy density, meaning they store less energy per unit volume. This decreases the maximum potential range for an electric vehicle, and means increasing the battery size in order to get more range. But larger batteries get heavy- very heavy, and expensive. When you think about how far long-haul trucks have to travel in a day on stretches of highways hundreds of miles long, it just doesn’t make practical or technological sense to battery-electrify them.
Enter hydrogen fuel cells, which have a much higher energy density than lithium ion. This means they store more energy in a given system per unit volume. No having to install a massive, expensive battery in the vehicle that will only last the truck driver so long before needing to charge up.
Hydrogen fuel also works a bit differently than batteries in powering the vehicle. The Economist has a great article on hydrogen advancements, that also dives into technical details: “for transportation, instead of storing and then releasing electricity gathered from the mains in the way a battery does, a fuel cell generates current from a chemical reaction between hydrogen and oxygen in the air.” The result? Only water vapour is emitted through the tailpipe, and 0 CO2 emissions- keeping our air clean.
In sum? The International Energy Agency estimates that by 2070, a quarter of medium-freight trucks on the road use hydrogen and fuel cells, and half of all heavy-freight trucks will be powered by hydrogen.
Top of page hydrogen truck image source: Autoevolution