Transportation - 16% of global emissions
Zero-emission vehicles and charging networks
The main progress in decarbonizing transport in the past decade has come from the rapid shift in the supply and demand of electric vehicles. Tesla made electric cars sexy, and now companies like Rivian and Lucid are ramping up to be new players in the space, while companies like Ford and GM are re-orienting their entire product suite around electric. EVs are generally more expensive than gas-powered automobiles, due to the cost of batteries. Range is also still a limitation for long-distance and/or heavy load trips. However, costs are becoming competitive and decreasing rapidly as investment ramps up, while range is increasing.
Today only 2.7% of passenger vehicles sold are EVs, though it’s expected that over half of vehicles sold in 2040 will be electric.1 As more companies are announcing plans to go fully electric, and battery cost curves come down, it is possible this transition will happen faster than expected.
A big limitation to consumer demand is switching away from the convenience and security that ubiquitous gas stations provide. Many people do not want to risk being hundreds of miles within a charging station, and then having to wait a long time for batteries to charge. Fortunately, there is momentum to alleviate those speedbumps: companies like Volta, Tesla, Revel are deploying charging stations, while different levels of governments are accelerating deployment through incentives and direct investment. Biden is pushing to invest $15B to roll out half a million charging stations nationwide (though it needs to pass through congress)2, while states like New York already provide $4,000 per charging port3. All the while, charging times are decreasing as we iterate on current lithium-ion technology and pioneer in solid-state batteries (see Pt2a for more on batteries).
Increased strain on our grid from EVs
As more transport goes electric, demand for electricity will go up accordingly. It’s estimated that grid demand will nearly double by 2050 in the U.S. if 66% of our cars are electric vehicles!4 This increased demand will require new generation, transmission, and distribution. Even worse for the grid, that demand clusters at roughly the same time in a given region: when people come home from work at night. Our grid, especially distribution, will have trouble handling that traffic all at once if we don’t build new infrastructure, and don’t develop more thoughtful solutions to spread out the increased load on our grid.
While Tesla has announced plans to release electric freight trucks for medium-range travel (300-400 miles), it will be a long road before long-range electric trucks are feasible (if ever), let alone economically sound. Companies like Proterra are ramping up electric bussing, due to the fact that most bus routes are short distance and buses can easily access charging ports within their routes. Meanwhile, companies like Remora are focusing on capturing the carbon that comes out of existing semi-trucks, helping mitigate the damage from what will be a long transition.
While batteries will continue to decrease in cost and increase in range, there are still constraints that will make it difficult to carry large amounts of goods over a long period of time. Remember from the previous discussion on batteries the best lithium-ion battery available today packs 35 times less energy than gasoline, pound for pound; while there will be major improvements in the coming years, it’s anticipated we’ll be able to get up to a 3x improvement, still leaving us with 12 times less energy per weight than gasoline.5 On the other hand, hydrogen is the most energy dense substance we know of, packing almost 3 times the amount of energy per weight compared to gasoline!6 For that reason, many people in the space feel hydrogen fuel cell technology will be the primary method of long-distance transport in the future.
Along with hydrogen’s obvious benefit of extreme gravimetric energy density, come some drawbacks. While it’s extremely gravimetrically energy-dense, hydrogen takes up a lot of space; to get hydrogen into a form that is easily transported, stored, and usable on vehicles requires very cold temperatures (about -250℃) and/or high pressure to make it more volumetrically dense. Additionally, since you cannot simply plug a hydrogen vehicle into an outlet, hydrogen may be restricted to industries that have networks of logistics hubs that vehicles regularly stop at those hubs (as is the case with trucking, aviation, and shipping) until a more robust supply chain is built out. One of the biggest constraints is that clean hydrogen is still expensive today; given the dramatic cost reduction of renewables, the falling costs of electrolyzers that make clean hydrogen, and the growing scale of clean hydrogen production facilities, it’s expected that the cost of hydrogen will be at a cost-competitive price by 2030.7
We’ll discuss hydrogen at a greater length in upcoming sections, as it will likely become a major player in the green economy in the coming decades.
Air and Sea. Hydrogen is looking to be the likely the future of aviation. Airbus has revealed three concepts for the world’s first zero-emission commercial aircraft which could enter service by 2035.9 New companies are also innovating in the space, such as ZeroAvia and Universal Hydrogen. ZeroAvia envisions a world where solar, wind and other renewables create hydrogen from water through electrolysis, and that hydrogen is used to fuel the highly efficient power trains they are developing. They are starting with smaller planes doing ~500 mile trips and have ambitious plans to build hydrogen-electric powertrains that will exceed the capabilities of the larger and faster planes we see today. Universal Hydrogen is building a modular capsule to more easily store, transport, and use hydrogen within aviation, much like Nespresso has done for coffee. They are also developing a conversion kit to retrofit existing regional airplanes with a hydrogen-electric powertrain, which they claim will improve both cost and performance, and will help transition existing planes, which have a ~20-year lifespan. Given the difficulties and lack of infrastructure to store, transport, and utilize hydrogen (even if you have planes that can use it) Universal Hydrogen’s work to simplify the logistics and usage chain has the potential to reshape the aviation industry.
Given the nascence of the clean hydrogen industry and the scale of the needed transition, there will be room for many innovative players in the space.
A quick note on electric planes... while they are possible, it’s difficult to travel long distances given their mass-to-energy ratio - planes are very weight sensitive. Given the energy to weight ratios compared above (gasoline and jet fuel are 35 times more energy-dense than batteries, hydrogen three times more energy-dense than gasoline and jet fuel), it’s unlikely we’ll see any 747 sized electric planes. Long-range shipping will likely follow a similar path as air travel.
What’s available today: While hydrogen may be the preferred choice of fuel in the future, the fact is today we have thousands of air and sea crafts that will be in use for the next 20-30 years. If you wanted to use an advanced biofuel instead of regular jet fuel, you’d pay $5.35, compared to $2.22, a 140% markup, not to mention it’s extremely hard to find such fuel.11 Breakthroughs are needed to create cheaper bio/synthetic fuels or get carbon capture costs much lower within the transition period to get to an economically sustainable price.
Time is of the essence when it comes to transitioning vehicles since it takes ~20-25 years for cars, planes, and ships to be fully replaced. Even after production switches to all clean vehicles, it will take some time before all vehicles are clean.
In addition to decarbonizing the mechanisms by which vehicles are propelled, a lot can be done to minimize the amount that needs to be moved by large vehicles. A lot of energy is wasted to move a car while it carries a single person in it. Prior to COVID, increasing shifts towards mass transit systems and ride-sharing were helping reduce the per person footprint of daily commutes; we should be able to revert back to those trends over time. Mass transit systems greatly reduce the energy footprint per person, and when designed well, can result in a faster commute time. Cities that took a thoughtful approach to mass transit see wide adoption, while those that did not are seeing the results you’d expect. In Singapore and London, half of trips are made via public transportation, while in the U.S. metropolitan areas, less than 5% of daily commuters use mass transit12. The Boring company’s innovations in tunneling have the potential to greatly reduce the cost of underground mass transit in the coming decades.
Cities that are biker friendly, such as Copenhagen, Amsterdam, San Francisco, and many in China, see much higher use of bikes and electric-pedal bike hybrids for transport - China accounts for ~95% of global e-pedal bike sales13.
Being thoughtful around how we design future cities to facilitate efficient transportation will be crucial, as we’ll be building the equivalent of one New York city space worth of urban development per month globally until 2060. Those urban areas will be home to over 68% of global dwellers.14
Tangential innovation impacting transportation
Much like the shipping container upended the entire shipping industry and society along with it in unexpected ways, one piece of technology that could have profound and surprising consequences for society is the rise of 3D printing. As 3D printing costs come down and the technology becomes more ubiquitous, it has the potential to dramatically reorganize supply chains. Items will be built fully automated, locally, on-demand. Previous factors like the cost of labor will be greatly reduced, and with it, the number of things that need to be transported long distances. This fundamental shift will lead to a more efficient and more resilient global economy and will chip away at the 40%+ of the transportation energy expended worldwide for freight15.
As with many parts of our decarbonization goals, the challenge when it comes to transport will come in reducing costs and deploying changes fast enough. Companies innovating in electric vehicles and hydrogen fuel cells are making sure we have a bright future full of clean transport; while that vision is beautiful, we still need to deal with the fact that over 95% of vehicles sold use fossil fuels and will be on the road 20 years from now. Companies and governments that are helping us reduce our energy footprint today (whether through ride-sharing, building robust transit systems, or retrofitting existing vehicles) are crucial in this transition.
It won’t be easy to decarbonize transportation, but we do have the fortune of having a visible path to decarbonizing the 16% of emissions that transport represents.
Gates, Bill. How to Avoid a Climate Disaster (p. 143).
Gates, Bill. How to Avoid a Climate Disaster (p. 59).
Hawken, Paul. Drawdown (p. 136).
Hawken, Paul. Drawdown (p. 146).
Gates, Bill. How to Avoid a Climate Disaster (p. 40). // un.org/development/desa/en/news/population/2018-revision-of-world-urbanization-prospects.html