How Do Hybrid Vehicles Impact the Environment?

More and more, we are demanding a cleaner, greener, environment. Much of the destruction that has been done to the environment comes from transportation, due to the fact that a majority of the vehicles on the road today emit harmful pollutants and waste, such as nitrogen gas, carbon dioxide, and carbon monoxide. With more regulation in the automobile industry to reduce these emissions, companies have responded by developing  more efficient vehicles, i.e. Hybrid vehicles. Although doing so will not have a significant impact until all vehicles on the road are hybrid, it still motivates people and other companies to follow suit, either by producing their own version or by buying one for themselves. Together, they are able to reach the common goal. With such a broad range of technology implemented in hybrid vehicles, we’ve come to believe that they are clearly one of the best substitutes one could ask for when trying to build a better environment.

Emissions chart for on-road vehicles

(above is a chart showing what percentage of which pollutant comes from cars)

Vehicles that run on oil and gas are a heavy burden on the environment, releasing chemicals, pollutants, and other wastes. Automobile manufactures are using hybrid vehicles to tackle this problem, as they release fewer and cleaner wastes, resulting in smaller pollution levels. Additionally, the technology in hybrids allow them to be smaller and quieter than traditional vehicles, a good amount of them being nearly silent, such as the Toyota Prius. Through engine-idle technology, energy recycling, and such technology, hybrid vehicles are also more fuel-efficient, boasting mileages that are twenty to thirty percent greater than traditional vehicles, thus allowing us conserve more of those resources.

Left: Clean, efficient, Toyota Prius hybrid
Right: Gas guzzling Hummer H2

Although this may so far seem very positive, hybrid cars actually have a significant negative impact on the environment.

To begin, compared to regular vehicles, who conventionally use lead batteries, hybrids use nickel metal hydride batteries. Nickel metal hydride batteries are much more toxic than lead batteries, but are used in hybrid vehicles because they are less problematic. Because they are toxic, challenges arise when trying to recycle or re-manufacture them, as companies try to dispose of this toxicity as efficiently as possible. Hybrids are also more difficult to build, as they are more complex and sophisticated, resulting in more energy used during the process.

Nickel Metal Hydride Battery (Used in Hybrids)

Lead Battery (Conventional Cars)

Also, many hybrid cars also feature a combustion engine, so in turn although they are not producing as many emissions, there is still a notable amount being released into the environment. The electric engine is used mainly at low speeds or when stopped, so while driving at high speeds, the combustion engine takes over and releases the same wastes as a conventional vehicles. Plug-in hybrids who run on electricity may be harming the environment without even knowing it! Depending on where you charge your vehicle, the electricity that is being pumped in the vehicle may come from a power grid that runs on oil or coal, causing you to be almost as harmful to the environment as someone driving a regular car. Additionally, many hybrid vehicles use copper in their motors and wiring. This copper must be mined, degrading and damaging the environment. When mining for copper, certain areas are cleared of their trees, grasses, and dirt to make room for digging and machinery. And while digging various metals and acids are released as air emissions.

So while hybrid cars may be the solution for a greener environment, many underlying issues need to be solved in order for this to be truly true. With a broad range of the types of hybrid vehicles available on the market today, a majority of them still aren’t as efficient as we’d like them to be, as they still produce emissions and damage the environment when being produced. Within the next decade though, these problems should disappear or become nearly irrelevant.






The Tesla Model S

The most talked about new electric vehicle is the Tesla Model S, designed by Franz von Holzhausen and Tesla Motors. Recently introduced to the US, this vehicle has already made its mark in the car industry. It’s a four door luxury sports sedan and features an 85 kilo-watt battery with a 265 mile range, the longest available range currently available in the market, and goes 89 miles per gallon. The Tesla is an all electric vehicle, equipped with 416 horsepower and a rear-mounted electric motor. Being a sporty electric car, it should go fast. But compared to other sports cars in its market, such as the hybrid BMW 5 series and the hybrid Mercedes E-Class, it’s much slower. But compared to other full electric cars, it is pretty fast; it has a top-speed of 125 miles per hour and goes from 0-60 in 5.6 seconds (the Toyota Prius is twice as slow, 90 miles per hours and 0-60 in 10.2 seconds).

On the outside, the Model S resembles a mix of a Jaguar and an Aston Martin, with daring exterior curves. The car comes with an all-glass panoramic sunroof and door handles that retract into the door of the car to reduce aerodynamic drag. Inside, the car features eight-way power-adjustable front seats, touch-sensitive door handles and a 17-inch touch-screen that controls the audio and navigation systems as well as climate and other controls. It was recently awarded Car of The Year, by Automobile Magazine.

(above is an image of the Tesla Model S)

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Types of Hybrid Vehicles

Now that we have an understanding of the technology hidden behind the world of hybrid vehicles, let’s have a look at the different types. The reality is that, not all hybrids are created equal! Hybrid cars are categorized based on their degree of hybridization and the drivetrains that they utilize. There are many kinds of hybrids, the main ones are; conventional hybrid, mild hybrid, full hybrid, and plug-in hybrid.

Conventional Hybrid:

Conventional hybrids are the most basic kind of hybrid vehicles out there. They utilize only two forms of hybrid technology; idle-off capability and depending on the vehicle, a system that sacrifices fuel economy for acceleration. As I mentioned in the previous post, idle-off capability is the cars ability to shut off the main engine at times when it is not needed, such as in heavy traffic, low speeds, or stop lights. The second, sacrificing fuel economy for acceleration, allows the car to run faster, but creates a disadvantage as it consumes more gas than other hybrids. Also, this type of hybrid does not allow for plug-in into an electrical source for the battery. Instead, it charges the battery through regenerative braking and and its gas engine.

Mild Hybrid:

Mild hybrids are a step up from conventional hybrids, although they too don’t have full capabilities. Mild hybrids have idle-off capability (like the conventional hybrid), regenerative braking, as well as an electric motor. The difference is that mild hybrids are more focused on fuel economy than conventional hybrids, eliminating the sacrifice of gas for acceleration. The disadvantage is that this kind of hybrid boasts a smaller engine/motor as well as weaker battery, making the vehicle less powerful. Some automakers provide the option to include direct-injection and turbocharging, allowing for them to maintain the same performance level; but of course, this comes at an extra cost. Regardless, it is a good alternative, because you get the main benefits of a hybrid car at lower cost and weight.

(above is chart comparing a mild hybrid vs a full hybrid, which we will cover next. Notice how the mild hybrid as much smaller battery pack and comes with a generator rather than an electric motor.)

Full Hybrid and Plug-in Hybrid:

A full hybrid has the three main features of a mild hybrid, but includes an electric motor, allowing the vehicle to save even more gas, as the electric motor can be used to power the vehicle. The arrangement of its electric motor, engine, and battery system make it so that the vehicle can drive using electricity at low speeds/cruising. If more power is needed, the engine kicks in and allows the vehicle to operate with twice as much power. The vehicles accessories, such as the a/c, windows, and radio are all powered using the battery. This system allows for more fuel consumption under certain circumstances. (The graphic above shows how a full hybrid system differs from a mild-hybrid system.) Plug-in hybrids are nearly identical to full hybrids, but come with batteries that are rechargeable using a wall plug and the vehicle is able to drive for more than 20 miles on electricity alone. Pretty innovative huh?

(above is an image of a plug-in hybrid being charged)

All hybrid vehicles offer innovative dual-source powertrains that will progressively introduce improved performance and efficiency statistics. Cutting-edge hybrid technology promises to be prominent in future, as it satisfies consumers that demand better fuel economy as well s those desiring performance. The future of the automobile appears to be promising, as this is just the foundation of hybrid vehicle technology.

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The Science Behind Hybrid Vehicles

With the creation of the automobile, we have been able to go from vehicles that rely on steam power (Cugnot Steam Trolley, 1769), to ones that run on gasoline (like the ones commonly used today), and are now moving towards hybrid vehicles. The question is though, what exactly is a hybrid vehicle? Is it one that runs on electricity? Is it one that runs on batteries? Or is it a combination of both? With a greater need for new energy sources, economically efficient vehicles, and rising gas prices, many hope that hybrid car technology is the ultimate solution.

Despite prior attempts to introduce hybrid cars to the market, sales of vehicles with this technology took off in 2004, thanks to the Toyota Prius II, one of Toyota’s best selling vehicles. With the Prius II, consumers had the advantage of using both gas and electricity in their vehicles. The gas engine produced 76 horsepower while the electric motor produced 67 horsepower, nearly equivalent, and a combined milage achievement of 65MPH.

Today, most hybrid cars utilize the same technology, using an electric motor/gas engine. By doing so, the energy from gasoline could be used to power a battery, capacitor  or directly power the engine, while the electric motor is used to drive the wheel. Alternatively, in “parallel” and “power split” hybrid vehicles, an engine and an electric motor share the work of driving the wheel. “Plug-in” vehicles store energy in lithium-ion battery packs by plugging the vehicle into an outlet, allowing for an increase in overall energy storage capacity. Generally, electric vehicles relies on energy from batteries to power the wheel, while in gasoline vehicles, gas is used to power the wheel. Although the process used by electric vehicles is much more efficient than that of gasoline vehicles, hybrid cars are more efficient because the minimize waste. For example, most hybrid cars use a technology that sends left-over energy back to the battery pack and show real-time gas milage, allowing for drivers to drive at an optimal speed to reduce their costs.

(Above is a comparison between the 2004 Toyota Prius II and a equally sized vehicle boasting a combustion engine)

Let’s go deeper and look directly at how this technology really works. There are five steps to making a vehicle a hybrid, or “hybridization”. The first is idle-off capability. Like lights that automatically turn on or off based on usage, this feature allows the gasoline engine to be shut off when not in use, but turn back on  and be ready to go by the time your foot is on the gas pedal. This is accomplished through the use of an electric motor garnering more than 100 volts. Similarly, conventional engines accomplish the same through the use of a 12 or 42 volt motor, although it isn’t as efficient. The second technology used is regenerative braking, mentioned in the previous paragraph. When a car accelerates, it builds kinetic energy. In conventional vehicles, when a vehicle slows down, the friction of mechanical brakes is used, turning the energy into hot brakes, therefore throwing it away. In hybrid vehicles, an electric motor aids the vehicle by recovering some the kinetic energy and converting it to electricity that can be stored in the battery and used at a later time, therefore reducing/eliminating waste. Third is power assist and engine downsizing. A hybrid vehicle utilizes both a gasoline engine and an electric motor, using the motor to supplement the engine to help accelerate the vehicle and slow it down. With a large enough motor and battery pack, the demands on the gasoline engine are reduced, allowing for the use of a smaller engine, while maintaining similar or greater performance. All hybrid vehicles use this technology, as it allows for greater efficiency and greatly reduces waste. Next is an electric-only drive setting. This technology allows the vehicle to drive using only the electric motor and battery, creating a full advantage from the electric side of the system. Through use of this, when starting up a Toyota Prius, the vehicle is so quiet it’s hard to realize it’s even on. Only the battery system is operating the car rather than the rumble of a combustion engine. This also allows the vehicle to operate the engine only when it’s reached optimal efficiency (Battery and electricity at low speeds, engine at high speeds). The final technology used is extended battery-electric range. This extends the use of the electric motor by recharging it from an energy source, such as a “plug-in”. Through the use of this, vehicles can run on battery-electric power for nearly 60 miles, improving environmental standards and performance. The downside to this though, is that a larger motor and battery pack is required to maintain good performance as well as sufficient electric range. (See below for a descriptive diagram)

(Above is a chart by General Motors further demonstrating the steps a hybrid-car uses to increase efficiency.)

Isn’t this amazing? Why haven’t we implemented this technology in all vehicles? Through the use of this technology, we are able to create new standards in the automobile industry. This would reduce the cost of production as it would be commonly utilized and at the same time achieve new environmental feats, a win-win for both sides! Follow me, as we next look at the different types of hybrid vehicles.

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