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What Makes it a Hybrid?
Many people have probably owned a hybrid vehicle at some point. For example, a mo-ped (a motorized pedal bike) is a type of hybrid because it combines the power of a gasoline engine with the pedal power of its rider. In fact, hybrid vehicles are all around us. Most of the locomotives we see pulling trains are diesel-electric hybrids. Cities like Seattle have diesel-electric buses -- these can draw electric power from overhead wires or run on diesel when they are away from the wires. Giant mining trucks are often diesel-electric hybrids. Submarines are also hybrid vehicles -- some are nuclear-electric and some are diesel-electric. Any vehicle that combines two or more sources of power that can directly or indirectly provide propulsion power is a hybrid.
Most hybrid cars on the road right now are gasoline-electric hybrids, although French car maker PSA Peugeot Citroen has two diesel-electric hybrid cars in the works. Since gasoline hybrids are the kind you'll find at your local car dealership, we'll focus on those in this article.
The gasoline-electric hybrid car is just what it sounds like -- a cross between a gasoline-powered car and an electric car. Let's start with a few diagrams to explain the differences between a gasoline-powered car and a typical electric car.
A gas-powered car has a fuel tank, which supplies gasoline to the engine. The engine then turns a transmission, which turns the wheels.
Gasoline-powered car
Move your mouse over the parts for a 3-D view.
An electric car, on the other hand, has a set of batteries that provides electricity to an electric motor. The motor turns a transmission, and the transmission turns the wheels.
Electric car
Move your mouse over the parts for a 3-D view.
The hybrid is a compromise. It attempts to significantly increase the mileage and reduce the emissions of a gas-powered car while overcoming the shortcomings of an electric car.
To be useful to you or me, a car must meet certain minimum requirements. The car should be able to:
Drive at least 300 miles (482 km) between re-fueling
Be refueled quickly and easily
Keep up with the other traffic on the road
A gasoline car meets these requirements but produces a relatively large amount of pollution and generally gets poor gas mileage. An electric car, however, produces almost no pollution, but it can only go 50 to 100 miles (80 to 161 km) between charges. And the problem has been that the electric car is very slow and inconvenient to recharge.
A gasoline-electric car combines these two setups into one system that leverages both gas power and electric power. In the next section, you'll learn about two different hybrid structures: a parallel hybrid car and a series hybrid car
Hybrid Efficiency and Performance
The key to a hybrid car is that the gasoline engine can be much smaller than the one in a conventional car and therefore more efficient. Most cars require a relatively big engine to produce enough power to accelerate the car quickly. In a small engine, however, the efficiency can be improved by using smaller, lighter parts, by reducing the number of cylinders and by operating the engine closer to its maximum load.
There are several reasons why smaller engines are more efficient than bigger ones:
The big engine is heavier than the small engine, so the car uses extra energy every time it accelerates or drives up a hill.
The pistons and other internal components are heavier, requiring more energy each time they go up and down in the cylinder.
The displacement of the cylinders is larger, so more fuel is required by each cylinder.
Bigger engines usually have more cylinders, and each cylinder uses fuel every time the engine fires, even if the car isn't moving.
This explains why two of the same model cars with different engines can get different mileage. If both cars are driving along the freeway at the same speed, the one with the smaller engine uses less energy. Both engines have to output the same amount of power to drive the car, but the small engine uses less power to drive itself. But how can this smaller engine provide the power your car needs to keep up with the more powerful cars on the road?
Let's compare a car like the Chevy Camaro, with its big V-8 engine, to our hybrid car with its small gas engine and electric motor. The engine in the Camaro has more than enough power to handle any driving situation. The engine in the hybrid car is powerful enough to move the car along on the freeway, but when it needs to get the car moving in a hurry, or go up a steep hill, it needs help. That "help" comes from the electric motor and battery -- this system steps in to provide the necessary extra power.
The gas engine on a conventional car is sized for the peak power requirement (those few times when you floor the accelerator pedal). In fact, most drivers use the peak power of their engines less than one percent of the time. The hybrid car uses a much smaller engine, one that is sized closer to the average power requirement than to the peak power.
Besides a smaller, more efficient engine, today's hybrids use many other tricks to increase fuel efficiency. Some of those tricks will help any type of car get better mileage, and some only apply to a hybrid. To squeeze every last mile out of a gallon of gasoline, a hybrid car can:
Recover energy and store it in the battery - Whenever you step on the brake pedal in your car, you are removing energy from the car. The faster a car is going, the more kinetic energy it has. The brakes of a car remove this energy and dissipate it in the form of heat. A hybrid car can capture some of this energy and store it in the battery to use later. It does this by using "regenerative braking." That is, instead of just using the brakes to stop the car, the electric motor that drives the hybrid can also slow the car. In this mode, the electric motor acts as a generator and charges the batteries while the car is slowing down.
Sometimes shut off the engine - A hybrid car does not need to rely on the gasoline engine all of the time because it has an alternate power source -- the electric motor and batteries. So the hybrid car can sometimes turn off the gasoline engine, for example when the vehicle is stopped at a red light.
The frontal area profile of a small and large car
Use advanced aerodynamics to reduce drag - When you are driving on the freeway, most of the work your engine does goes into pushing the car through the air. This force is known as aerodynamic drag. This drag force can be reduced in a variety of ways. One sure way is to reduce the frontal area of the car. Think of how a big SUV has to push a much greater area through the air than a tiny sports car.
Reducing disturbances around objects that stick out from the car or eliminating them altogether can also help to improve the aerodynamics. For example, covers over the wheel housings smooth the airflow and reduce drag. And sometimes, mirrors are replaced with small cameras.
Use low-rolling resistance tires - The tires on most cars are optimized to give a smooth ride, minimize noise, and provide good traction in a variety of weather conditions. But they are rarely optimized for efficiency. In fact, the tires cause a surprising amount of drag while you are driving. Hybrid cars use special tires that are both stiffer and inflated to a higher pressure than conventional tires. The result is that they cause about half the drag of regular tires.
Use lightweight materials - Reducing the overall weight of a car is one easy way to increase the mileage. A lighter vehicle uses less energy each time you accelerate or drive up a hill. Composite materials like carbon fiber or lightweight metals like aluminum and magnesium can be used to reduce weight.
All of the hybrid cars on the market utilize some or all of these efficiency tricks. Let's take a look at the hybrid models you can buy right now.
Anyone with experience with A2B Electric Bikes or others?
Nathalie
Anyone have any experience with the A2B Electric Bikes?
http://www.ultramotor.com/us/product/
I'm thinking of getting one (or other brands if you have any other recommendations to look at) to ride to work, I'm about 12 miles from work and with some power-assist it would help be get there faster and not as sweaty as if I completely rode 12 miles on my mountain bike. (I've ridden to work before but my old house was 4 miles from work, now I'll be 12 miles away)
Not sure yet if I want the Hybrid or Metro model..
But in general, I'm wondering how these bikes are on ONLY peddle power? For example, say I want to mainly ride on my own peddle power and then use the electric motor once I get tired (either with or without peddling, although peddling shouldn't be too hard if power-assisted even if I'm tired)
I'm concerned with the bike being heavy (55 lbs or so I believe) how hard it is to peddle..
Anyone with experience on these or other electric bikes?
I have a motorcycle so I'm not looking for only a scooter.. I want the exercise but at the same time 12 miles is too much for me to only peddle to work, especially here in the heat of South Florida.
Thanks
Answer
I would ride the motorcycle to work and buy a nice road bike for the $2,300 that bike would cost you. You can travel at 15 mph very easily on a road bike, that's the max speed on the hybrid and you would have a $1,000 or so left over. If you want to get exercise do it after work when it won't hurt to sweat a little.
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