About this series: As a BTG supporter, you understand that our transportation choices have tremendous ecological impacts, but you may not be aware of the latest innovations and improvements in your options. With this series, we hope to help you find new ways to both lower your individual impact now and move us all toward a sustainable transportation system ASAP. Please send us any additional suggestions you have.
In Part 1, we looked at options for getting around without a car at least some of the time as well as how some of us may even be able to avoid owning a car entirely.
In Part 2, we looked at how to drive greener when you do and what to consider when trying to decide whether to keep your current car or buy a new one.
In Part 3, we considered the impacts of driving a plug-in car.
Now, in Part 4, we explain some obstacles to electrifying our car culture.
As we explained in Part 3, a high-MPG hybrid is better for the climate than an electric car in KC unless you can charge from clean energy sources. That’s because our regional electric grid is still heavily dependent on inefficient and highly-polluting coal-fired power plants.
That’s not the only problem with electric cars, though. They also have too much range.
Now you might be thinking, “I thought the problem with electric cars was they have too little range.” From one perspective, you’d be right, because most electric cars do have significantly less range than conventional cars and hybrids do.
From an efficiency perspective, however, you’d be mistaken. That’s because the longer the range of an electric car, the higher energy storage-capacity its battery pack needs. Batteries are much less energy-dense than gasoline, so an electric car with more than a hundred miles of range is by necessity much heavier than a comparably-sized gasoline-powered car.
This matters a great deal because the more weight the electric motor has to haul around, the more electricity it has to use per mile. That increase in weight undercuts the increase in range from using a higher-capacity battery pack.
Research shows that electric cars with a maximum range of about 70 miles on a full charge would meet the daily needs of most Americans while maximizing efficiency. Unfortunately, automakers are convinced that Americans won’t buy electric cars in large numbers unless they offer hundreds of miles of range. Consequently, every electric car manufacturer is working to dramatically increase range. This trend is exemplified by the brand-new Chevy Bolt, which has an estimated average range of 238 miles on a full charge based on the EPA’s testing procedure.
And it’s certainly true that many Americans want to be able to drive hundreds of miles on a whim (even if they never do). That desire has weighty consequences: The Bolt’s 60 kilowatt-hour (kWh) battery pack weighs 960 lbs. This makes the Bolt really heavy for a small hatchback, with a curb weight of 3,563 lbs.
In comparison, the most similar conventional Chevy, the slightly-smaller Sonic hatchback, has a base curb weight of 2,848 lbs when equipped with an automatic transmission. Hauling around an extra 715 lbs. takes a lot of energy, so a Bolt with one-third as much range would use considerably less energy per mile.
The large battery packs necessary to provide long range-travel on a single charge are also the primary reason why electric cars are considerably more expensive than comparably-sized conventional cars.
To use the Bolt again as an example, its starting price is $36,620 whereas the starting price for the Chevy Sonic Hatchback with an automatic transmission is $18.970. The Bolt is nearly twice as expensive.
Even after subtracting the available $7,500 federal tax credit, the Bolt is a very pricey small hatchback. That high price will inevitably constrain the number of Americans willing to go electric. The benefits of any new technology will be limited if it’s too expensive to be widely adopted. If Chevy had sized the battery pack to provide ⅓ the range, the Bolt’s price could have been much more competitive with comparable conventional cars and many more people would be able to afford to make the switch.
And the Bolt’s 960-lb., 60 kWh battery pack is only able to store energy equivalent to less than two gallons of gasoline. How can that be?
Each gallon of gasoline contains the equivalent of 33.7 kWh of electricity, and a gallon of gasoline weighs about 6 lbs. Even if you add in the weight of the plastic fuel tank, the energy storage system of a conventional car weighs a fraction of the energy storage system of an electric car.
This enormous disparity between the energy-density of gasoline and that of current and projected battery technologies is a major obstacle to simply switching from driving gasoline-powered cars to driving electric cars.
The obstacles are even more formidable when it comes to long-haul trucks and buses. A battery-pack that would have enough capacity to give such a large and heavy vehicle a long-range on a single charge would take up too much space and weigh too much to be feasible. It also appears that basic physical limitations will make it impossible for batteries to ever match the energy-density of gasoline.
Another obstacle to trying to perpetuate the American car culture by switching to electric cars is the sheer scale of new infrastructure that would require. It will already be an enormous challenge to build enough solar and wind and other clean energy systems to supply electricity for buildings and other stationary users quickly enough to avert a climate catastrophe. If we were to also try to replace the 384.74 million gallons of gasoline the US Energy Information Administration says we used on average every single day in 2015, the challenge would be far more daunting. And then there’s diesel fuel to replace, too.
And we need to keep in mind that manufacturing and installing clean energy infrastructure still requires burning fossil fuels.
In the end it seems clear that there is no way to sustain our car culture over the long-term. The longer we try to keep it going, the more damage will result.
Conversely, the sooner we go all-in on transitioning our transportation system away from personal automobiles, the better off we and the rest of the world will be.