Electric and autonomous vehicles will change the layout and rhythm of our lives. Entwined with this story of change are the fuels and forms of energy we used to enable the engines and motors to propel us forward. In this excerpt from his upcoming book, noted energy expert Michael Webber makes the case that switching from oil to electricity for powering vehicles would cut transportation-related carbon emissions and create a pathway to quieter, zippier travel.
The desire to explore is a defining aspect of humanity. Transportation has shaped our societies:Where we can feasibly travel in the course of our day-to-day activities orders a great deal of our lives. And as our vehicles change, our concept of place changes along with it. Transportation has given shape to countries: Canals did it in the early 1800s; rail did it in the late 1800s through the first half of the twentieth century, and highways did it in second half of the 20th century.
Electric and autonomous vehicles will change the layout and rhythm of our lives yet again. Entwined with this story of change are the fuels and forms of energy we used to enable the engines and motors to propel us forward.
Transportation can be powered by electric motors as well as by external (steam) and internal combustion engines. While the idea of electric vehicles seems like a modern concept, they have been around for over a century and have intellectual roots that go back further. James Prescott Joule, the pioneer in thermodynamics, saw an electric future for transportation. “I can hardly doubt that electro-magnetism will ultimately be substituted for steam to propel machinery,” he said in 1839. The transition to personal electric vehicles has been a long time coming.
Electric motors operate in a fundamentally different way than mechanical engines. They are inherently compact, quiet, and have fewer moving parts. They provide full torque even at low speeds, whereas mechanical engines give their highest power output at a few thousand revolutions per minute (rpm). That is why mechanical engines have complicated transmissions and clutches, so the driver can get a lot of power even when the car isn’t moving or is at low speeds. Unfortunately, those additional moving parts, belts, and crankshafts are all prone to failure, making the maintenance of mechanical vehicles more expensive.
Not only do electric vehicles have fewer moving parts that can fail, but also they do not produce fumes (because they do not have tailpipes)and they are much quieter. The gentle whir of an electric motor is much softer than the thousands of explosions per minute contained inside metal combustion engine blocks, which require muffling to comply with city noise ordinances.
Transportation systems that aren’t continuously connected to electric rails or overhead wires (as trains and streetcars are) need to bring their own energy source with them. Such vehicles need an onboard storage device and a powerblock—a fuel tank and an internal combustion engine for a conventional car, or a battery and a motor for an electric vehicle. Hybrid vehicles have a fuel tank and a battery combined with a motor and an engine, which is one reason that hybrids sometimes cost more than their conventional counterparts. One challenge of this approach is that batteries are relatively pricey, heavy, and bulky compared with gasoline. A tank of gasoline is a simple structure that holds a lot of energy. Getting 500 miles of range from a single tank of gasoline is a pretty standard achievement for modern cars, whereas it requires significant technical advance to get 200 or more miles of range from an electric car.
Modern freight trains in the United States are diesel-electric trains. They carry diesel onboard, which is much more compact than a battery capable of pulling a train the same distance. The engine’s sole purpose is to drive a generator to power an electric motor that drives the train’s wheels. That way the train combines the energy storage benefits of diesel with the high torque and ease of control of an electric motor. In Europe and Asia, the train systems are highly electrified—and also much faster.
For buses or trash trucks, which are already heavy (and therefore would not be hobbled by the additional weight of a battery) and travel a fixed route before returning home at night, electricity is a compatible source because the batteries could charge while people are sleeping. In fact, the London Electrobus Company launched a fleet of 20 electric buses in 1907, and they worked fine for several years before the company shut down because of financial irregularities. A little over a century later, electric buses are making a comeback: Cities in China are replacing entire fleets with electric buses as a way to reduce air pollution.
A similar trend is afoot for personal automobiles. Some cities like Paris are banning diesel engines because of concerns about the air pollution emanating from tailpipes. Norway is offering steep incentives to consumers to support electric cars. In parallel, the cars are attractive to customers because of their quick acceleration and quiet operation. As a consequence of these converging factors, electric vehicle adoption is growing exponentially. This trend has economywide impacts because electrified drivetrains are more efficient than combustion-based systems.
Transportation is a major energy user, responsible for about 29 percent of total US energy consumption, mostly in the form of petroleum products burned in internal combustion engines operating with about 25 percent efficiency. That means that nine of the 12 gallons in a car’s fuel tank are wasted (rejected as heat into the atmosphere) and only three are used for propulsion.
If we replaced all 3 trillion miles per year traveled by light-duty trucks and cars operating on 25 percent efficient combustion engines with 70 percent efficient electric vehicles, the economy’s overall energy efficiency would be substantially improved and emissions would drop dramatically. If only wind, solar, and nuclear energy were used for the electricity to charge those vehicles, then about 1.3 billion metric tons (out of nearly 6 billion tons) of annual CO2 emissions would be avoided. That means electrified transportation is not only a pathway to quieter, zippier operation, but is also cleaner and more efficient.
Expanding on that point, electric vehicles get cleaner over time as natural gas, wind, and solar replace coal in the power sector, whereas combustion engines get dirtier with time as their systems degrade from normal wear and tear.
Electric transportation enabled one key innovation in mass transit: an extensive subway system. While the very first stretch of the London Underground system operated on steam locomotives that produced noxious fumes from the fuels they burned, smokeless electric trains were a much better fit for the poorly ventilated tunnels. With electrification, subway systems proliferated in the late 1800s through early 1900s. Subways transformed cities because they facilitated the mass movement of millions of riders without taking precious real estate or farmland on the surface. One observer noted that the subway essentially made New York City what it is, by bringing rich and poor people of many races and backgrounds together. With densification came a need for mass transit, which enabled more densification.
Compared with other transit systems, subways are a different kind of beast. Generally speaking, people don’t want to live near airports because they are noisy, generate pollution, and attract traffic jams. But people like to live near subway stations because the noise and fumes are out of sight and out of mind, and they offer great convenience for moving around a city. That’s the result of electrification of mass transit, which together create a vast underground ballet of coordinated movement of people and machines.
Though the subway is well over a century old, it is a precursor to other concepts for underground transportation that moves people and goods at high speeds. I had the opportunity to work at the RAND Corporation, the nation’s oldest and most distinguished think tank, from 2004 to 2006. RAND was and is a special place where many good ideas flourish. RAND employees conceived of the communications satellite, the copay for health insurance, and the control deck for the starship Enterprise in Star Trek. I would occasionally thumb through their old reports because I was amazed at all the gems I would find.
One breakthrough report from 1972, “The Very High Speed Transit System” by Robert M. Salter, was particularly prescient. It laid out the concept of a high-speed, low-pollution alternative to air travel that used tunnels with highpowered pneumatic devices. It was inspired by the desire to save energy but also would avoid weather-related problems above ground. Imagine high-speed guinea pigs in their habitrails or the tubes at drive-through banks that use air to push or pull containers of your money from your car to the teller and back. That’s the concept presented in the RAND report. It’s also an ancestor of the core idea presented as Hyperloop by Elon Musk. It’s as if there are no new ideas under the sun.
Robots on the Road
Turning to electric vehicles and switching from automobile ownership to ride-sharing in self-driving vehicles could reduce congestion by smartly controlling traffic flows using knowledge of where other travelers are going. Also, cars could be smaller. Most of us drive a singleoccupancy car that has room to seat four or five even though we rarely need it. With point-topoint mobility services for our commuting, vehicles could be tailored for the purposes of moving just a few bodies, which means they could be smaller.
Our recent research at the University of Texas at Austin has concluded that when the full lifecycle costs of owning your own vehicle are considered (the cost of insurance and taxes on your garage at home, paying to park at work, maintenance, fuel, and the lost productivity of time spent driving), using a mobility service is the best economic option for over a quarter of the population using standard conditions from 2017. As the prices for mobility as a service drop, then that will be the economic option for a much larger fraction of society. Professionals who live in suburbs would benefit from using mobility services. Instead of wasting their time driving, commuters can rest, read emails, place phone calls, or conduct other business. That work can create economic value—and reduce workers’ office hours so they can get home earlier for dinner.
The rise of mobility services and self-driving cars might be as transformative as cars were in the first place. Imagine this scenario:We all have our own chauffeur who picks us up at our door the minute we’re ready and drops us off at work or the grocery store, driving along roads with smooth traffic and sparing us the hassle and time of finding a parking spot. En route, we can read, text, think, sleep, or talk on the phone without fear of causing an accident.
These mobility services with autonomous vehicles will save energy in a number of ways. Robotic drivers will be programmed to follow the best practices of driving—they won’t have lead feet and bad habits. Embed more information into the cars and the surrounding infrastructure, and traffic will move more smoothly, reducing congestion, smog, and energy consumption. A suite of connected cars that know what the other cars plan to do will make traffic lights obsolete; instead, the cars will continuously weave around each other at crossings. Safety will improve because each car will automatically know where the others are headed, reducing the risk of collision, just as planes do in the sky.
And since the cars will be better matched to the needs of the riders, there won’t be lone commuters in gas-guzzling SUVs that only make sense on the occasional weekend. When you need to tow a boat, you could arrange for a robot-driven truck. Otherwise a smaller commuter car will be the primary vehicle of choice.
The cost of the vehicles will be shared through the mobility service company, keeping ownership costs down per mile traveled. Rather than each of us paying 100 percent for a $30,000 car we use 4 percent of the time, we will all pay for a more expensive car, but only when we need it, with one car meeting the needs of many. Auto insurance companies will likely have lower rates to reward the improved safety of robotchauffeured cars compared to human-driven cars, creating a nice market incentive to get a ride.
People who really want to drive will pay extra insurance to reflect the additional risk they are introducing on the roads. Parents who really want their teenagers to drive can pay a premium yet higher. Once these technologies and market signals align to point in the same direction, the trends will be irreversible.
If you love to drive and worry that society will lose this critical skill set as we hand our transportation needs over to machines, then consider this: Some clever entrepreneur will sell you the opportunity to drive old beat-up cars in a circle on a dusty ranch while reliving the past. After all, that’s what we do when we want to teach our kids how to ride horses.