The first $35,000 Tesla Model 3s are rolling off the line The Guardian: "First Tesla Model 3 rolls off production line" rolling off the line The Guardian: "First Tesla Model 3 rolls off production line" this month in the US. But Tesla’s not alone in racing to meet our fossil-free future. Other car makers are also working hard to expand their all-electric offerings.
But wait – doesn’t an electric car actually emit more greenhouse gases than its conventional counterpart? After all, you still have to mine all the ingredients The major components at present are nickel, lithium, copper, cobalt, graphite, and aluminum, and sometimes manganese. for its thousand-pound Electric car battery weights vary, but the lightest ones in today’s compact cars still come in around 600 pounds. The Chevy Bolt’s battery weighs 960 pounds, and the Tesla Model S battery is a whopping 1,200 pounds. battery and then generate the electricity you’ll use to charge it up.
It’s a question I’ve been asked time and again over the past few months, whenever I tell people that I write about battery packs and electric cars.
It’s an understandable question. The main reason I think electric cars are worth writing about is that, once charged, they don’t emit a single gram of anything while you drive them. But that still leaves the following questions in need of answers:
- How much greenhouse gas is released in mining the car’s raw materials, often on the other side of the world, as a result of the (possibly fossil-sourced) energy used in the mining process?
- How much is released in refining those materials and in manufacturing and disposing of the car and its battery?
- And how much is released in generating the electricity the car uses?
What follows is an attempt to quantify those answers as accurately as possible. To get the best results, I focused on one place and time: my own country of the Netherlands for the year 2017. But my findings are relevant wherever you may live and drive.
Of course, the situation will be somewhat different in other countries. At EIA.gov you can see how different countries generate electricity. Of course, the situation will be somewhat different in other countries. At EIA.gov you can see how different countries generate electricity. In Holland, most of our electricity is generated by burning natural gas, for instance, while the US generates relatively more electricity using nuclear power plants (which – indirect emissions included – emit less CO2 than gas-fired plants). Germany, on the other hand, burns more coal and lignite (which are more polluting than gas). And in both the US and Germany, people drive relatively more highway miles than in tiny Holland. These facts produce somewhat different results.
Ultimately, though, these differences aren’t all that important. Once electric cars – no matter where they are – run on 100% renewable power, then the results will be pretty much the same everywhere.
In the rest of this article, I’ll limit my discussion to CO2 emissions – because when it comes to cars, carbon dioxide is by far the major contributor to the greenhouse effect. The other relevant contributors are nitrogen oxides and sulfur oxides (which pollute the air and indirectly reinforce the greenhouse effect) and particulate matter emissions. And I’ve already written in depth Here’s my article on mining raw materials for EV batteries (in Dutch only). written in depth Here’s my article on mining raw materials for EV batteries (in Dutch only). elsewhere about the mining industry’s impact on the local environment.
The car, the fuel, and the driving
I’ll divide my quest for hard numbers into these three phases:
- manufacturing the car (including maintenance and end-of-life disposal and recycling)
- producing the fuel (gasoline, electricity from mixed sources, and 100% renewable electricity)
- driving the car (on-the-road emissions)
I assume that electric and gasoline cars both last for
This is the figure used for midsize cars in the US by the Union of Concerned Scientists in their 2015 report, Cleaner Cars from Cradle to Grave. The TNO’s lifespan assumption (which I used for my computations) is a shade longer: 136,700 miles (or 220,000 kilometers).
According to the Royal Dutch Touring Club (the AAA of the Netherlands), you can expect a gasoline engine to last for 155,000 miles (250,000 km). How long an electric car and its battery will last is uncertain – Nissan guarantees its Leaf (the best-selling electric car in the Netherlands) to 100,000 miles (161,000 km), and Tesla gives buyers an unlimited warranty for the first 8 years. That said, a Dutch driver put 271,000 km (some 168,000 miles) on the odometer of his Tesla Model S in three years, and California transportation service Tesloop racked up 200,000 miles (322,000 km) on one in just over a year. present the CO2 emissions for all three steps, and then calculate the total.
After that, I’ll use the resulting differences to look at what going full-on electric in the Netherlands could mean for the environment. In 2014, passenger transport was responsible for at least 10% of our country’s total CO2 emissions. In many Dutch towns and cities, transportation is the primary source of these emissions.
For context, these are the European Union’s climate goals: by 2050, cut CO2 emissions from road traffic by 60% (relative to 1990 levels), cut industrial emissions by 80%, and decarbonize electricity production almost entirely.
One more crucial piece of context before we begin
It may seem odd to start off a comprehensive look at the numbers with my next point, but it’s an important one: the current differences in emissions from electric and gasoline cars are largely irrelevant.
To limit climate change on the planet, we have to stop using fossil fuels. That means we need automotive technology that frees us from needing petroleum and natural gas to get from A to B. It also means we need to start generating electricity from non-fossil sources now, so that coal- and natural gas-fired power plants can be decommissioned in the next few decades.
Here’s the thing: an electric car can run on 100% renewable energy, which is by definition impossible for a car powered by petroleum products
Here’s the thing: an electric car can run on 100% renewable energy, which is by definition impossible for a car powered by petroleum products. So it’s really of limited importance whether electric cars are a greener alternative right this very second.
Another cautionary note: calculations like the ones below inherently promote a false sense of accuracy. For my calculations, I use the assumptions made by the TNO research institute, which published a report TNO is an independent nonprofit organization focused on applied science research. Its mission is to develop innovative, practicable knowledge to benefit society. I took my assumptions from a study TNO conducted at the request of the Netherlands Enterprise Agency, a Ministry of Economic Affairs office that works to encourage sustainable, innovative, and international business. in 2015 comparing the CO2 emissions (and emissions of other gases) from different cars. I chose this report because it focuses specifically on the Netherlands – because as we’ll see, the assumptions you start with make a big difference.
Richard is TNO’s Principal Advisor for Sustainable Transport & Logistics.
at TNO, who’s been making calculations like these for 25 years, warned me about that in a phone call: “If you tweak your assumptions a little, on justifiable grounds, you can end up with vastly different results.”
For the actual driving, TNO assumes one-third city miles, one-third highway miles, and a final third that falls in between. This is a plausible assumption for the Netherlands. “But,” Richard Smokers cautions, “if you assume far more highway miles in your calculations, your results will favor a diesel car, which uses its energy most efficiently at a steady high speed. And an electric car will come out looking worse, because driving fast drains the battery faster.”
For the electricity powering the car, TNO used the average emissions for all the power consumed in the Netherlands. Another option would be to look at which specific power plant has to kick it up a notch when someone plugs in their electric car – and whether, at that instant, it might be a polluting coal-powered plant. discusses two important assumptions TNO made and examples of how you might plausibly change them.)
Last but not least: knowing the points in an electric car’s life where it emits carbon dioxide is a good thing, period. It tells us where there’s room for improvement. I hope the comparison below will add insight there, too.
Not interested in the gory details? Jump straight to the final result here.
Want even more detail? Here are three notes on why I left diesel cars, At present 71% of all cars run on gasoline. In general, we can say that diesel cars are cleaner than gasoline cars in terms of their emissions. Manufacturing a diesel car releases a little more CO2, but producing diesel fuel and driving the car both emit less because diesel cars are more fuel efficient (the difference is about 4% CO2 per kilometer). The diesel car had been gaining ground, but it now seems to have reached its peak (thanks in part to Dieselgate). hybrid cars, The reduction in carbon emissions you achieve by driving a hybrid car like the Toyota Prius depends heavily on your driving style and the size of the battery. and hydrogen cars I’ve ignored hydrogen and other fledgling sustainable technologies because there are no real passenger car options for consumers at this time. out of the equation.
1. Manufacturing the car
Take a conventional car and an electric car and saw them lengthwise down the middle. The most immediately obvious difference between them is the component that provides them with energy.
In a gasoline car that’s a hollow vat at the back, made of plastic, steel, or aluminum: the gas tank. In an electric car it’s several hundred pounds of battery cells, usually down in the floor.
Making that battery emits far more CO2 than making a hollow tank. Aside from the energy it takes to mine the elements used in the battery, you have to consider their refinement and the battery’s production.
But just how big is that difference, exactly?
Estimates on CO2 emissions from battery production vary widely. So the researchers at TNO averaged the figures from five studies into different types of EV batteries between 2008 and 2013 and concluded that
manufacturing a battery
This takes every facet of the process into account, including maintenance, disposal, and recycling (a process that consumes energy, but also delivers raw materials you thus no longer have to mine out of the ground).
emits an average of 150 kg of CO2 per kilowatt-hour (kWh) of battery capacity.
A battery’s capacity tells you how far you can drive before recharging. If we assume an electric car needs at least 60 kWh of capacity before we’re willing to buy it, Current Tesla models have a capacity between 60 and 100 kWh; the Nissan Leaf, BMW i3, and Renault Zoe have 20 to 30 kWh. Of the electric cars on the road in the Netherlands, the most common capacity is currently 60 kWh, which is also the expected capacity for the upcoming Tesla Model 3. then the battery’s production – a one-time event – emits 9 metric tons of carbon dioxide.
But the battery isn’t the only difference between the cars: the body is sometimes (but not always) made of lighter materials. If that material is aluminum, then its manufacture emits more CO2 than if you’d used old-fashioned steel.
How much difference the body material makes varies significantly from one car to the next, and from one study to the next. TNO ultimately decided not to include those differences, for practical reasons. Richard Smokers explains why: “A major reason why we assume the same materials are used for the body in both conventional and electric cars is that the lightweight materials already being used in EVs will be adopted en masse for conventional cars within a few years. There, too, the car’s weight needs to drop to improve fuel efficiency. Those new materials are expensive, but the financial tradeoff is already worth it for EVs because a lower body weight means less expensive batteries for the same range.”
And so we end up with a difference of 9 metric tons in CO2 emissions during the car’s production, in favor of the gasoline version.
2. Producing the fuel...
Now we’ve got our cars, and it’s time to hit the road. For that, we need fuel.
Gasoline is made from petroleum, which first has to be drilled, transported, refined, and then delivered to a gas pump.
A battery-powered car runs on electricity. You fill it up using a charging point at your home, on the street, or at a fast-charging station.
...assuming the Netherlands’ standard electricity mix
Electricity can be generated in many ways. Here’s how it was generated in the Netherlands in 2014:
How does this affect CO2 emissions?
For the current Dutch electricity mix (20% renewable and 80% traditional), TNO calculated 447 grams of CO2 per kWh. Burning coal releases roughly twice as much CO2 as burning natural gas, largely from differences inherent in the two fuels. Important fact: coal-fired power plants emit roughly twice the CO2 For power plants running on coal, emissions are roughly 800-850 grams per kWh, and for plants running on natural gas, about 350-400 grams per kWh (according to TNO). of natural gas-fired power plants.
Generating renewable power emits an average of 36 grams of CO2 per kWh – including what’s emitted in making the solar panels and windmills.
Now we need to compare these figures to the CO2 emitted in producing gasoline. Comparing apples to apples, that’s 57 grams per kWh. For gasoline, this is usually expressed in megajoules, but for clarity’s sake I’ve converted to kWh here. That number only includes the CO2 emitted during drilling and refining.
But we’re still missing one step. When gasoline is burned – later on, when we drive off – only 22–30% of the energy is converted into forward motion. The rest is lost as heat and friction.
We have to compare that efficiency with the efficiency of a power plant and of an electric car. A natural gas-fired power plant – the kind that generates most of the Netherlands’ fossil-sourced energy – is more efficient than a conventional car: the return on a modern facility is 50–60%. But even that pales in comparison to an electric car’s efficiency.
An electric car uses 74–94% of all its energy for propulsion. This high efficiency comes mostly from the electric powertrain’s higher energy conversion efficiency, and partly from its ability to reclaim some of the energy spent in braking.
What does this mean? It means that for the Netherlands’ standard electricity mix, you only need about half as much energy to drive an electric car the same distance as a gasoline car. For sustainable electricity, you don’t even need a third as much.
...and assuming renewable electricity
Before we use these numbers in our calculations: what kind of power do the 15,000 EV drivers in the Netherlands actually use? Is it this average, largely fossil-sourced, energy mix?
The answer seems to be no.
Here’s what I found: right now, there are some 13,000 public charging points and 15,000 semi-public Such as those installed at stores for customer use. charging points in the Netherlands, plus a few hundred fast-charging stations.
Dutch municipalities are supposed to supply all their public charging points with renewable energy. There’s current (and justified) debate on exactly how well they’re meeting that requirement, Some of the companies that deliver power to the Netherlands’ public charging points provide 100% renewable domestic energy (usually from wind, as with EVNet’s and Allego’s charging points). Fastned’s fast-charging stations also deliver 100% renewable domestic energy. But a recent spot-check by WISE Nederland revealed that some Dutch municipalities have signed power purchase agreements with companies that still invest in coal-fired and nuclear power plants. but if we ignore the debate for now, then we can assume the Netherlands’ public charging points supply 100% sustainable power.
What kind of power do the 15,000 EV drivers in the Netherlands actually use?
As far as I could confirm, semi-public charging points are only partially sustainable. That leaves a third category: the kind of power those 15,000 electric-car drivers use at home and at work, where most of the Netherlands’ charging points are installed – an estimated 72,000 This number is the Netherlands Enterprise Agency’s estimate, based on a 2012 study extrapolated to 2016 using the actual number of currently registered electric vehicles. at present.
There aren’t any hard and fast numbers here. The spokespeople I talked with for Fastned Fastned is a for-profit company that runs (at the time of writing) sixty fast-charging stations in the Netherlands. and for EVNet EVNet is a joint initiative of the Netherlands’ six electric power distribution system operators that manages (at the time of writing) roughly 3,000 public charging stations across the country. said they had the sense that EV drivers are generally very environmentally aware. So you’d tend to think that most electric-car owners have chosen a power company that supplies 100% renewable energy.
I calculated the two extremes: a scenario in which electric cars use the current Dutch electricity mix, with 80% generated by traditional fuels, and the ideal scenario, in which our electric cars all use 100% renewable energy.
That gives us the following results for the car’s fuel production, which instantly reveals why charging your EV with sustainable electricity is an excellent idea.
3. Driving the car
The gas tank is full, the battery’s been charged. Now we can hit the road!
According to TNO, burning gasoline in a modern compact car releases an average of 275 grams of CO2 per mile driven. The TNO uses the kilometer equivalent: 170 g per km. An older or larger car will release more. Assuming you drive it for 135,000 miles, The TNO figure is 220,000 km. it will emit a total of over 37 metric tons of CO2.
And how much CO2 will the electric car emit? Zero. Nada. Zip. Draining a battery doesn’t emit even one molecule of carbon dioxide.
And just like that, the gasoline car is now the worse polluter.
The grand total: lifetime CO2 emissions for electric vs. gasoline cars
To recap our story so far: manufacturing an electric car’s battery belches out a bunch of CO2 at the beginning. But even if we run that car on the Netherlands’ current electricity mix, the average EV is still significantly cleaner than the average conventional car. That’s because producing both a car and its fuel ultimately contribute far less to its CO2 emissions than the actual driving.
An electric car running on 100% renewable power emits just a third of the CO2 a gasoline car emits, even with today’s technology
In practice, electric cars in the Netherlands probably use power that’s cleaner than the country’s average mix, making an EV’s total CO2 emissions even lower.
But the real point is this: an electric car running on 100% renewable power emits just a third of the CO2 a gasoline car emits, even with today’s technology.
This – eliminating CO2 emissions while driving – is where we need to get to, and thanks to the invention of the electric car, we can get there. As a bonus, the electric car’s battery will serve as part of the solution we so desperately need for storing excess renewable energy. Because generating electricity from solar and wind power depends on external factors – whether the sun is shining or the wind is blowing – we need a way to store the excess for use when it’s dark or calm.
What does this mean for the climate?
If we’re going to limit global warming to 2 degrees Celsius in the coming century, our road traffic emissions in the Netherlands will have to drop by 60% in 2050 compared to 1990 (that level is roughly the same as in 2015). Here we’re talking about the CO2 emitted during actual driving, for all vehicles.
With on-road CO2 emissions of zero-nada-zip, the electric car is an excellent means toward this end. (You might say it’s what it’s made for.) That’s why the Netherlands Environmental Assessment Agency has concluded that by 2035 we should stop selling gasoline cars altogether. And the environmental committees of the four political parties likely to be in the Netherlands’ next coalition government Like many other European countries, the Netherlands has a multi-party parliament in which no single party has a simple majority. After each election, several of the larger parties – generally two to five, usually three or four – will enter talks to form a coalition government. These talks can take months, depending on how wide the gap separating their platforms is. have even set the date ten years earlier. The four parties’ environmental committees propose to ban the sale of vehicles that run on fossil fuels starting in 2025. Read more in this April 26, 2017 article at the NL Times. have even set the date ten years earlier. The four parties’ environmental committees propose to ban the sale of vehicles that run on fossil fuels starting in 2025. Read more in this April 26, 2017 article at the NL Times.
But that’s not all. Carbon dioxide emissions from energy production in the European Union must also drop, by at least 80%. It’s clear how the electric car fits in there: all EVs need to move to 100% sustainably sourced electricity as soon as possible. Because generating power from the wind and the sun is a zero-carbon activity.
Three developments that will make the electric car even cleaner – much cleaner
So now we know that manufacturing batteries for electric cars emits a lot of CO2. But that’s also precisely where promising opportunities for improvement lie.
For an earlier article in this series, I visited Umicore, an innovative Belgian company that’s betting big on battery recycling. Right now they’re targeting cell phones, but they’re already adapting their facilities to handle electric car batteries. In fact, they’ve recently partnered with Tesla. Read more about Umicore’s partnership with Tesla on Tesla’s blog. In fact, they’ve recently partnered with Tesla. Read more about Umicore’s partnership with Tesla on Tesla’s blog.
What I learned at their plant, which I’d never heard before, is this: we can already recycle the heck out of EV batteries. Even today, we reclaim more than 95% of the three major metals they contain: nickel, copper, and cobalt. And a reclamation process is currently being developed for lithium – the metal the battery is named for, though it’s not its major component.
We will undoubtedly cause more damage to the earth and the environment as we mine the materials to build electric cars. But in contrast to drilling for oil, this mining will be a finite process. At some point in time, we’ll barely need new mines at all.
What’s more, the opportunities for EV and battery innovation are huge – much greater than for conventional cars and petroleum. For example, countless researchers around the world are currently looking for ways to replace graphite by the more easily obtained silicon, which has a much higher energy density. Read a summary here of recent research into silicon’s advantages as a replacement for graphite. silicon, which has a much higher energy density. Read a summary here of recent research into silicon’s advantages as a replacement for graphite. Graphite mining is a major polluter, The Washington Post visited graphite mines in China. a major polluter, The Washington Post visited graphite mines in China. and the mineral is hard to recycle.
Last but not least, battery factories can become greener, much the way electric cars can. For the calculations in this article, I followed the lead of expert researchers and assumed that battery factories use largely fossil-sourced electricity in the production process. They, too, could switch to using renewable energy – and some already have.
Tesla, for example, is building a massive zero-emissions factory in Nevada. Instead of a pipeline pumping in natural gas, the Gigafactory will have a roof packed with solar panels. Windmills surrounding the plant will generate the rest of the energy required. Read more about the Gigafactory’s renewable energy plan here. the rest of the energy required. Read more about the Gigafactory’s renewable energy plan here.
Recycling, innovation, and the greening of factories can dramatically reduce the CO2 emitted during EV battery production. For those reasons, the figures I’ve used in this article are more likely too conservative than too optimistic, even for the immediate future.
Want to know more about the situation in other countries?
Before I realized I needed to focus on one country for my computations, I reviewed several international life-cycle and cradle-to-grave analyses. For those of you interested in the international context, here’s a short list to check out:
The Union of Concerned Scientists wrote an easy-to-read report on its two-year analysis of climate emissions from cars: “Cleaner Cars from Cradle to Grave” (2015) Read the UCS report Cleaner Cars from Cradle to Grave here. “Cleaner Cars from Cradle to Grave” (2015) Read the UCS report Cleaner Cars from Cradle to Grave here.
A recent paper in the academic journal Applied Energy Here’s a well-to-wheels analysis for a number of countries from the Applied Energy journal. paper in the academic journal Applied Energy Here’s a well-to-wheels analysis for a number of countries from the Applied Energy journal. analyzes the situations in Brazil, China, France, Italy, and the US (2016)
A report by the University of Dresden Here’s a University of Dresden report on the German situation (in German only). report by the University of Dresden Here’s a University of Dresden report on the German situation (in German only). that calculates more somber figures for Germany (2014; in German)
A white paper by World Auto Steel Here’s World Steel’s analysis of CO2 emissions for steel vs. aluminum bodies. white paper by World Auto Steel Here’s World Steel’s analysis of CO2 emissions for steel vs. aluminum bodies. takes a closer look at the difference in CO2 emissions from using steel vs. aluminum car bodies (2016)
De Correspondent members
Dieuwertje develops life-cycle assessment (LCA) methodology at the University of Bordeaux. Her dissertation addressed different ways to include recycling in the LCA process.
and Wiljan Smaal Wiljan studied applied physics at the Delft University of Technology in the Netherlands. He currently manages a research platform for printed organic electronics at the University of Bordeaux. read an earlier version of this article, provided invaluable feedback, and made me realize that I needed to rewrite the whole thing to focus on one country initially.
Dieuwertje also tipped me off to the existence of a scientific journal that’s entirely devoted to the art of the life-cycle assessment – with a special issue on electric cars – and read the second version of this article.
De Correspondent member Jack van Dijk pointed me toward an investigative report by Germany’s Krautreporter Krautreporter: ‘Dein Elektro-Auto ist Keine Öko-Revolution’ (in German only). an investigative report by Germany’s Krautreporter Krautreporter: ‘Dein Elektro-Auto ist Keine Öko-Revolution’ (in German only). which made me realize that current emissions figures depend heavily on which country you’re in.
De Correspondent member Jan Derk Stegeman Jan Derk studied aerospace engineering at the SUPAERO institute in Toulouse, France. From 1994 through 2000 he worked in the helicopter department at the Netherlands Aerospace Center in Amsterdam and developed software in his free time. He’s currently a freelance nerd. provided inspiring input on another – completely different – way to look at the question. For this article, I used his comment that the assumption of a 135,000-mile lifetime for an electric car may be on the low side (see the info card above for more on that).
Richard Smokers at TNO provided crucial context for TNO’s report and made sure I didn’t do anything crazy with the numbers. His colleague – and De Correspondent member – René van Gijlswijk René is a researcher in the Sustainable Transport & Logistics department at TNO. helped me calculate the grand total.
I can’t thank you all enough! Any errors that remain are mine alone.
—Translated from Dutch by Grayson Morris and Erica Moore
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