The Emissions Discussion

Since I started this blog I’ve been contemplating how to handle the elephant in the room. Are electric cars actually better for the environment compared to Internal Combustion Engines (ICE)? For my fellow Albertan’s, it certainly isn’t intuitive to think that a car getting the majority of it’s power from coal fired power plants can be better for the environment than our traditional ICE vehicles. In fact, it’s the subject of numerous meme’s and hate on social media. (I’m sure more than one of you readers have seen the above Tesla with the Coal Powered licence plate being shared on various feeds).

Mazda 3

FuelEconomy.Gov

The worlds focus on vehicle emissions has been growing significantly in the past several years. One of the studies undertaken resulted in a very useful tool from the US Department of Energy.  Through the use of this tool we can easily see the actual results for emissions for my wife’s current car measured scientifically. The 2012 Mazda 3 has a 55 liter gasoline tank. Using it’s EPA rated economy (8.7 liters per 100 km), we can determine that the car has a single tank range of 632 km. [Our real world use has this closer to 500 km of range, but most of our driving is in the city]. Additionally, the car has been calculated to emit 204 grams of CO2 per kilometer. If one were to completely fill the tank and drive for the full 632 kilometers, the car should have emitted 129 kilograms of CO2.

Tesla

FuelEconomy.gov

So, how does an electric vehicle, like the Tesla perform? Unfortunately, it’s going to take a little bit more work to figure out the comparison. Unlike the ICE, an electric vehicle (EV) doesn’t directly convert a fuel to energy; instead that is performed at the Power Plant and the EV only stores that energy in its batteries. However, the US Department of Energy does provide us with the information needed to calculate a fair comparison. The Tesla Model S 90D requires 32 kWh of energy to travel 100 miles (20 kWh per 100 kilometers), and would then need to consume 126.4 kWh of energy to travel the same 632 km as the Mazda.

But for a more complete comparison,  we need to figure out how much CO2 is emitted to provide the EV car with that 126.4 kWh of energy. First we have to charge the car, which is only 90% efficient (as some of the energy is lost to heat) which increases the demand to 140.4 kWh.  Then we have to get the energy from the Power Plant to the charger. In Alberta, our electrical grid has been measured to be about 95.5% efficient. After accounting for this loss, the Power Plant must generate 147.0 kWh of energy. According to a separate study, Alberta generates 820 grams of CO2 per kWh of energy produced. Therefore a Tesla will produce (820 grams * 140.4 kWh) 115 kilograms of CO2 to travel the same 632 km the Mazda 3 did.

Ok, so are we really going to see a benefit from having a car that produces only 10% less CO2 than our old car? In order to evaluate a complete comparison, we must consider the same factors when considering emissions for an ICE vehicle. As with our EV, we need to consider that the gasoline burned in the ICE isn’t naturally occurring and must be extracted, refined, and transported to our local gas station and the emissions resulting from that process need to be included in the comparisons between the vehicles. A second point to consider is that when the power plant transitions to cleaner methods of  electricity production,  the emissions required to operate the EV  will see an immediate benefit. An ICE cannot become more efficient as the vehicle ages.

In order for gasoline to be produced, oil must first be extracted from the ground and transported to be upgraded at a refinery. The average refining process requires 6 kWh of electricity to produce a gallon of gasoline (1.5 kWh per liter). That now means the Mazda 3’s 55 L tank requires 82 kWh of electricity to refine the fossil fuels it uses (and an additional 67 kilograms of CO2).  When you add this to the emissions that the ICE vehicle generates itself in order to convert that fuel to energy, the EV now becomes much more efficient than previously thought.  We also need to consider that the finished gasoline product is then transported from the refinery to be distributed to our local gas stations. Many methods are used to achieve this, including road, rail, and/or perhaps pipelines. How we choose to deliver this product each have their own individual challenges. Road and rail transportation requires diesel engines that burn their own fossil fuels and create their own emissions. Pipelines are much more efficient but have a greater potential for environmental releases. (I still believe pipelines are the best choice for those with an environmental conscious, but that is topic for another debate). Fortunately, Alberta doesn’t import any oil like our Eastern provinces as marine transportation of Oil has massive environmental impacts.

As for Alberta, we currently have a commitment to eliminate our coal power plants and ensure that 30% of our energy is obtained through renewable sources by 2030. This means that the moment our Alberta grid reduces it’s carbon footprint the electric vehicles also return the benefit. For myself personally, I do plan on installing a residential solar array. Once in place, we would be able to travel with 0 CO2 per kilometer.

Finally, lets talk about the batteries. Yes, they do require their own resources to be produced. They contain materials like lithium which is a naturally occurring metal found in mineral pools and brine deposits. It can then be extracted in a way with very minimal environmental impacts (scientists are currently working on a method to mass produce lithium from sea water). Even if the mining process was as damaging as to the environment as some people claim (it’s not), electric vehicles still break even on their manufacture impacts very early on. The batteries are sealed and will finish their life with the materials intact (unlike the thousands of liters of fuel we burn an ICE’s lifespan). We can then recycle over 99% of the battery  due to the valuable metals it contains.

I definitely think that now is already the right time for Albertan’s to realize the environmental benefits of electric vehicles. After all, there is no other vehicle that I can think of that is better for the environment as it ages. What do you think? I encourage you to leave your feedback below.