One topic that arises when discussing alternative vehicle options is the practicality of electric vehicles. Specifically, investigating factors such as ownership costs - factoring in battery replacement, practicality issues, and environmental impacts help understand the real-world positives and negatives of electric vehicles. Proponents of Electric vehicles (EVs) and internal combustion engines like to talk past each other. Advocates for electric vehicles like to talk about zero driving emissions, and not having to go to gas pumps. Those in favor of internal combustion talk about battery replacement costs, and lack of range.
This section examines some common reasons for buying an electric vehicle.
The true cost of running an electric vehicle is a complicated issue, not the least because the running costs of both EVs and internal combustion cars can vastly vary. While the US Environmental Protection Agency (EPA) uses 23 MPG as the benchmark for new-car mileage, in reality, most cars in the same classes as current EVs get over 30 MPG, with many achieving over 40. This immediately decreases the potential savings over a gasoline-powered car. Furthermore, battery replacement costs are generally over $10,000 at the point of writing. While outright battery replacement will not affect people who lease their vehicles, it will absolutely affect resale costs down the road, as a new buyer will potentially have to absorb battery replacement themselves. As a general rule, the more kilometers driven in a year, the lower the comparative running costs of an EV. That said, people who drive a lot often times drive longer distances, which brings up the problem of range. With a vehicle like the Mitsubishi i-MiEV, which is designed to be a city car, range is basically not a problem. According to Mitsubishi, their battery will have about 70% of its original capacity after 10 years, but even then, it will not need to be replaced, unless range is a concern. This allows the i-MiEV to offer huge amounts of savings over its lifetime without incurring any extra costs for battery replacement.
A possible financial incentive to own an EV is to take advantage of time-of-day energy pricing utilizing the cars battery. Energy prices fluctuate throughout the day due to changes in demand. Money can be made by charging EV's during low demand at low prices and then selling that energy back during peak demand and high prices. Although this is not yet an option for many EV owners, only minor upgrades to grid operation and electrical meters is required.
The overall environmental impact of EVs comes from a variety of factors. Nissan advertises their Leaf as a Zero-Emissions vehicle, and while it's true that no CO2 comes out of a tailpipe, there are generally carbon emissions associated with electricity generation. For example, in China, where 75% of electricity generation comes from coal, replacing a gasoline-powered car with a similar-size electric car would only reduce greenhouse gas emissions by 19 percent. On the other hand, in British Columbia, Canada, where roughly 90% of electricity generation comes from hydro, EVs really do emit almost no CO2 in their driving cycle.
According to Carbonzero.ca, flying from Calgary to Seattle emits 0.28 tonnes of CO2, while driving emits just 0.21 tons of CO2. While this 33% increase is not huge, CO2 from a plane is emitted directly into the upper atmosphere, so its warming effects are felt sooner than CO2 from a car. While this increase in emissions is more than offset by driving an EV on a daily basis, it is worth noting that if a person makes short airplane trips often, driving an internal combustion car is better on emissions than flying. If having an EV forces people to take a significantly larger number of plane flights, it may not be saving as many greenhouse gases as people might think.
Electric car range is a difficult issue. Short range off of a tank of fuel is not a problem with an internal combustion car, because the tank can simply be refilled. With an EV, range tends to be shorter than internal combustion, and this problem is compounded by the fact that "refueling" take hours, not minutes. According to Statistics Canada, in 2011, 15.4 million Canadians commuted to work, and 79.6% of them did so using a private vehicle. The average Canadian drives just under 47 kilometers per day. Since the range of every production electric vehicle in Canada exceeds this distance, carmakers make the argument that an EV is suitable for most people. By extension, this should mean that pretty much every person in Canada should buy an EV, right?! Not quite.
What car makers (purposely) don't take into account is that many people enjoy travelling to further-away destinations on weekends, or for holidays. The abovementioned drive from Calgary to Seattle would take a minimum of 58 hours in a Nissan Leaf, assuming a high-output charging port is handy when the battery went to empty (calculation here). Use the included 110V charging instead, assuming ideal charging points, and the trip time extends to around 133 hours, or five-and-a-half days!
Tesla Motors has proposed a plan to allow "hot-swappable" batteries for their cars. In a video from the company, they show the battery switch taking place in just over 90 seconds. They then compare this to an Audi A8 refuelling, which takes just over four minutes. While this video does show proof-of-concept, that electric cars can be practically refueled, it does not, as Elon Musk states in the video, prove that electric cars can be more convenient. This is because the diesel-powered car that they use, an Audi A8, has a 23.8 gallon fuel tank, capable of taking it more than 1,000 kilometers in combined driving, and over 1,350 kilometers on the highway. Getting Tesla's 426 kilometers (265 miles) on a charge, the Tesla will have to swap at least two batteries to go the same distance as the Audi. Three, if it's all highway driving. On top of this, Tesla proposes charging the equivalent price of 15 gallons of gas for a swap. Dividing by the range, that's an equivalent fuel cost to a car that gets 17.6 MPG, which is about the same as an average medium-duty truck. The battery swapping plan introduces convenience, but high cost basically eliminates any cost saving benefits of an EV. What it does allow, however, is for people to use their EV on a daily basis, charging at home, but not be constrained by range requirements when they do want to travel further away from home.
While EV range may be lacking now, the future looks promising. At the rate battery technology is developing, we can expect energy densities to go up, allowing for longer range between charges. Similarly, while Tesla's battery-swapping technology is too expensive right now, increased usage should lead to lower prices, meaning that in a few years, the idea of swapping batteries would make a lot of sense.
While the range of an EV may be enough for most daily driving, and be extremely convenient on a daily basis, drivers should make note of how many longer (100+km) drives will be taken. This means, EV drivers have to have a plan for getting to a destination if the EV does not have sufficient range.