The Motley Fool is reporting Electric vehicles (EVs) are expected to be one of the world’s fastest growing green technologies in the next 10 years and Mercedes, Tesla and BMW are taking the lead in offering a number of new and exciting choices for consumers.
With all this hoopla, the Nissan Leaf was still the best-selling EV in 2015, with well over 165,000 EVs sold since it was introduced in 2010, according to GreenTechMedia.
Total worldwide sales of EVs and plug-in hybrid electric vehicles (PHEVs) in 2014 amounted to 320,000 in 2014 and were forecast to exceed 500,000 units at the end of 2015. While cumulative sales are only one percent of the global auto market, it is believed that EVs and PHEVs are here to stay.
The battery is the big difference
The major difference in an electric car, compared to a gasoline-powered car is the battery. When the electric car’s battery pack is combined with an electric motor and the motor’s controller, you’re talking about the “brains” of an electric car.
Stay with me now. The motor’s controller takes its power from the batteries and delivers that power to the electric motor. The accelerator pedal (gas pedal on a gasoline-powered car) is hooked up to a pair of potentiometers (variable resistors) that tells the controller just how much power it is supposed to deliver.
When using the accelerator as you would the gas pedal on a gasoline-powered car, the controller can deliver absolutely no power, like when the car is turned off, full power when the accelerator pedal is mashed to the floor, or any level of power in between.
The biggest challenge to electric car technology is the battery
Electric vehicles or EVs can run on AC (alternating current) or DC (direct current) motors. EVs with DC motors can run on anything from 96 up to 192 volts. Many DC motors come to us from the forklift industry. If the EV has an AC motor, it’s a bit more complicated because the motor is more than likely a three-phase AC motor running on 240 volts of AC power along with a 300-volt battery pack. Now that’s enough to pique someone’s interest.
And that brings us to the need for better battery technology if electric cars are going to continue to gain in popularity. Most experts agree that the “holy grail” for EV batteries is getting costs down to around $100 per kilowatt-hour from the present cost of $250 to $300 per kilowatt-hour.
It is believed that by reducing the cost per kilowatt hour to $100 or less to operate an EV, then, and only then would they be able to compete with the gasoline engine in conventional cars today. To put the cost in perspective, say electricity costs a consumer 12-cents a kilowatt-hour, and the home uses 900 kilowatt-hours of electricity in a month, the total cost would be $109.00.
With gasoline-powered cars, many people want to know how much horsepower an engine has, right? With the new EV technology, you would ask, “how much kilowatts does that car have?” Both are measurements of power. A little bit of history is needed to explain kilowatts, OK?
Back when horsepower was first used, it described the theory that a horse could do 33,000 foot-pounds of work in a minute, or to put it simply, a horse can move 1,000 pounds of “whatever’ 33 feet in one minute. Based on this theory, a 300-horsepower engine can do the work of 300 horses in the same length of time.
While most countries use horsepower to measure a gasoline engine’s power output, Australia uses kilowatts. Obviously, one kilowatt equals 1,000 watts. So when an EV like the Nissan Leaf has an “80 kW AC synchronous motor,” this means it has an AC electric motor that runs on alternating current and produces 80 kilowatts.
So to figure out how an 80-kilowatt motor compares to a gasoline-powered engine, a little conversion is needed. To convert kilowatts to horsepower, multiple the number of kilowatts by 1.34. In this example, 80 kilowatts is about 107 horsepower.
There are several problems to overcome in improving upon EV batteries, including weight, bulk, capacity, charge, lifespan, and the price, according to How it Works. Solving these problems will eventually reduce the cost per kilowatt-hour, making EVs more economical to operate.
This means having a battery that isn’t as heavy as the ones in use today, and also requires making a battery with better energy density. Lithium ion batteries may show some promise although they have a number of deficiencies that need to be overcome, such as a short life cycle, toxicity and being quick to degrade over time.
Tesla’s Musk says they hope to solve many of the lithium ion battery problems within the next 10 years in its Giga factory. Tesla and Panasonic are throwing billions into improving lithium ion batteries. Building on lithium-ion battery tech seems to be the biggest trend right now, and a breakthrough would be huge for EVs and their future growth.
This story is Part 1 in a series that focuses on electric vehicles and where this green technology is headed. Part 2 will look at future trends and advances, including innovations in lightweight carbon-fiber bodies and automation.
