Electric cars are all the buzz these days. There is so much innovation going on in this industry that it is tough to keep up. Especially if you’re new to the idea of electric cars. So, here are some of the most common questions people ask answered.
What Exactly Are Electric Cars?
This seems like a simple question with an obvious answer. But, it can still get confusing because there are so many variations of electric vehicles. The term ‘Electric Cars’ or ‘Electric Vehicles’ are umbrella terms with a broad definition in today’s media. But, they generally refer to any vehicle that uses electric power to propel the vehicle. This includes both fully electric cars and semi-electric cars such as hybrids.
All electric vehicles (EVs) have an electric motor that gets its power from an electric current. This current comes from a source such as a battery. In fully electric cars, only electricity drives the vehicle, so it needs quite a powerful source for the electric current. As these cars are fully electric, they don’t emit any greenhouse gases into the air while driving.
In semi-electric cars such as hybrids, however, electricity works alongside regular gasoline. They alternate between the two sources, depending on which one is more efficient for certain driving conditions.
What are the types of Electric Cars?
Fully electric cars include Battery Electric Vehicles (BEVs) such as the Nissan Leaf and Tesla Model S. As well as Fuel Cell Electric Vehicles (FCEVs) such as the Toyota Mirai. In full-electric cars, there are no internal combustion engine. Nor any parts that relate with them such as fuel tanks, pipes or pumps.
Battery Electric Vehicles (BEVs) use battery packs (a collection of many individual battery cells) to draw the electric current to power the electric motor. As this is the only source of the current, the batteries have to very powerful. As a result, these battery packs could be quite heavy or expensive. The batteries are rechargeable and need charging once they drain.
Fuel Cell Electric Vehicles (FCEVs)
Fuel Cell Electric Vehicles (FCEVs) use fuel cells to generate the electric current for the motor. The fuel cell uses the electrochemical reaction between hydrogen fuel and oxygen in the air to produce an electric current. Similar to regular gasoline vehicles, they refuel with hydrogen fuel. Although FCEVs are generally clean and don’t give out emissions. They do produce water vapor as a by-product of the chemical reaction.
Hybrid Electric Vehicles (HEVs) uses both electric power and gasoline to propel the vehicles, hence these are semi-electric cars. This means HEVs have both a battery pack and an internal combustion engine. It’s not full reliant on electricity, so the battery pack doesn’t need to be that big. The battery charges through an internal mechanism called regenerative braking. So they can’t or need to be charged by an external power source.
Plug-In Hybrid Electric Vehicles (PHEVs) are a variation of hybrids, where the batteries can be charged by an external power source. Hence, they can rely more on electric power and could produce less emissions.
Although ‘Electric Cars’ include all these variations of electric vehicles, in this article electric cars refer to ones that are fully electric.
How do Electric Cars work?
Battery Electric Vehicles (BEVs) work by having a battery pack that draws an electric current to drive the motor. The battery pack composes of thousands of individual battery cells that store the electrical energy needed. The batteries have to be very powerful and have a high power-to-weight ratio as BEVs solely rely on this battery pack to drive the vehicle.
They electric motor used in all electric vehicles, not just BEVs, is an induction motor. Alternating current (current that changes direction periodically) will produce an alternating magnetic field, which will cause the rotor in the motor to turn.
However, the current coming from the battery pack is DC current and a conversion to AC current is necessary to be fed into the motor. This happens through an inverter which converts DC to AC current. Technically, BEVs can use DC motors as well but these tend to be bulkier, which is not ideal for an EV that already has a heavy battery pack. So, AC motors are more preferable to BEV manufacturers.
Regenerative Braking
Another important aspect of all electric vehicles is regenerative braking. When a car brakes, all that kinetic energy from the momentum converts to heat and goes to waste due to friction with the road surface. Regenerative braking attempts to recover this energy and turn it into useful electrical energy.
Regenerative Braking works by causing the induction motor to turn in the reverse direction during the car’s braking. When turning in the reverse direction, the motor acts like a generator and converts the kinetic energy of the car into electrical current. This current goes to the battery pack to store for future use.
Fuel Cell Electric Vehicles (FCEVs) work by producing an electric current during the electrochemical reaction between hydrogen and oxygen in the fuel cell. The fuel cell has three key components: a terminal holding a positive charge (called a cathode), a terminal holding a negative charge (called an anode) and an electrolyte between the anode and cathode. Here’s what happens in the fuel cell in detail:
What are the main benefits of electric cars?
Fuel Economy
Electric cars have great fuel economy, thanks to their energy saving mechanisms such as regenerative braking. This means that there’s less energy waste and hence less fuel waste. This will ultimately translate to greater fuel cost savings. In traditional cars, fuel economy is miles-per-gallon.
Fuel economy is essentially the distance travelled per gallon of fuel in miles. As EVs use electricity that isn’t measured in gallons, there’s a measurement called equivalent miles per gallon or MPGe. They use the electrical equivalent of a gallon of gasoline fuel to measure fuel economy.
Electric vehicles generally have very good fuel economies compared to regular gasoline vehicles. This is because not only do they have energy saving methods like regenerative braking, but electric motors are inherently far more efficient than internal combustion engines (an estimated 80% vs 30%).
BEVs like the Tesla Model S have an MPGe of 98, which is comparatively higher than say a Chevy Cruze Sedan which has an MPG of 52. Other BEVs such as the Nissan Leaf and Chevy Bolt have even higher fuel economies of 112 MPGe and 119 MPGe respectively.
For FCEVs, MPG is the distance travelled per gallon of hydrogen fuel, so it’s similar to measuring fuel economy in regular gasoline vehicles. FCEVs also have a high fuel economy, such as the Toyota Mirai 2016 model that has an MPG of 66.
Fuel Cost Savings
Although the upfront cost of an EV may be higher, you will end up with greater fuel cost savings annually due to the increased efficiency of EVs and the fact that electricity is a bit cheaper than gasoline. Electricity prices are also more stable than gasoline prices.
The cost of gasoline fluctuates in the range $1.50-$4 per gallon of fuel. In comparison, it costs only $1.20 to travel that same distance using electricity.
As a matter of fact, a 2018 study found that the average annual cost of operating EVs is less than half of the cost of operating a regular gasoline car. In the US, the average annual cost of operating an EV is around $457 while for a gasoline car, it is $1,117. Basically, with electric cars, you can get twice the mileage for the same money.
Lower Emissions
This is probably the most prominent benefit of EVs, especially BEVs. As they operate entirely on electricity, they don’t release toxic greenhouse gases into the air while driving. While you could argue that electricity comes from fossil fuels, they still have a lower carbon footprint compared to regular gasoline vehicles.
It is estimated that for a mid-size BEV, there’s almost a 50% reduction in CO2 emissions per mile. This is in comparison than a mid-size gasoline vehicle.
Of course, even the best EVs aren’t 100% clean. There are still emissions involved in the manufacture of the car itself. However, from cradle-to-grave, BEVs still produce the lowest emissions of any car.
FCEVs are also largely emission-free if you only consider CO2, but they do produce water vapor as a by-product.
Less moving parts means less maintenance and repair costs.
With EVs and hybrids, there is more electronic control over the key functions in the car such as the changing of the speed. For an EV, to change the speed of the vehicle, it simply needs to change the current that is feeding into electric motor. In traditional gasoline vehicles, however, the speed changes and some of the key functions are controlled through mechanical parts.
Due to this, there are less moving parts in an EV compared to a gasoline car. The transmission of an EV is a simple, one-stage transmission whereas this is more complicated in a regular car. Moving parts are the biggest source of failures and repairs, so, an EV would need less maintenance and repair work because of this.
EVs also don’t have internal combustion engines and parts associated with them, such as fuel tanks, pumps and pipes. Overall, you can save up on maintenance costs too.
What are the main drawbacks of electric cars?
Despite its eco-friendly performance, there are still some drawbacks of EVs that are preventing them from completely taking over gasoline vehicles.
Range: The maximum distance that can be travelled on a single charge is still lower than that of a regular car on a full gas tank. The BEVs with the highest range is the Tesla Model X with a range of 237 miles and the Chevy Bolt with a range of 238 miles. This is still quite low compared to the ranges of regular diesel cars.
Charging: As BEVs are totally reliant on electric power, they need to be charged regularly, because the ranges are quite low on a single charge. This is because the battery packs are still quite heavy and so, the ones used are quite light and not as powerful. The charging time is also another huge drawback of BEVs. They can take as long as 2 hours to be charged fully and even longer if charged at home.
Featured Image – Photo by Lance Cpl. Dave Flores
Source – https://www.29palms.marines.mil/News/Photos/igphoto/2001540823/
