One of the great fears about owning and driving an all-electric vehicle is running out of juice. Most every driver has had the uncomfortable experience of seeing the gas gauge rapidly approach "Empty" and having to search for a gas station. However, unless you're driving out in the country, a gas station is probably not too far away. And if the dreaded event happens, and you do run out of gas, you can fairly easily get a container of gas from the nearest station, put it in your tank, then drive to the station. A giant nuisance … maybe even a giant embarrassment … but actually pretty easy to resolve.
But what if you're driving an all-electric vehicle? There's no equivalent to a can of gas to stick in your tank. So far as I know, no one makes a portable battery that you can attach to the car to give it enough fuel to get you to the nearest charging station. And unlike gas stations, electric charging units are still not particularly commonplace.
Then when the driver is able to re-charge the vehicle, it takes a long time. While the typical driver can put 15 or so gallons of gas in a vehicle in five minutes, re-charging an electric vehicle usually takes a minimum of 30 minutes at a high power charging station, and about six to eight hours if one plugs into an ordinary outlet. The thought of spending 30 minutes in a charging station is very practical much of the time.
So it's quite understandable that lots of people are nervous about driving an all-electric vehicle for fear of running out of juice.
It's an obvious problem, but maybe the real problem is that we're all working off of the wrong "mental model". The "mental model" I'm referring to is the one about filling the tank of your auto with gas. We're all in the habit of letting our gas tanks get close to empty, then refilling the tank until its full. This model makes perfect sense when you think about the "nuisance factor" of putting petroleum in your auto or truck. Filling the tank completely makes complete sense when the task is so annoying.
But what if there was a different "mental model" about filling the tank? The model I'm thinking about is related to the old riddle, how do you eat an elephant? The answer, of course, is, one bite at a time. If we apply this idea to putting fuel in your auto or truck, it would mean that we would add fuel to the vehicle a little bit at a time. If it is a conventional vehicle, it would be as if you added one gallon of gas at a time. Of course, it's pretty unlikely that you'll stop at a gas station fifteen different times, each time adding one gallon of gas, to refill the tank. The same thing is true of an all-electric vehicle. You're very unlikely to stop the vehicle, plug in to a charging station for a short time, then do that all over again a short time later.
There's no way to get petroleum into your vehicle without attaching a hose to it, but there actually is a way to get electricity into an electric vehicle without attaching a cord to the vehicle. As I'll show below, this could provide a convenient way to "eat the elephant", or recharge your electric vehicle.
The idea is based upon the concept of induction. Basic electromagnetic induction works by supplying power to a charging station that includes an induction coil. The electric current causes the induction coil to create an electromagnetic field around itself capable of transferring power to a second induction coil nearby. Applying this principle, one can recharge an electric vehicle without plugging it in to the electric supply – cordless recharging. The idea of wireless transfer of energy was first suggested more than a century ago by renowned inventor Nikola Tesla.
Several companies now sell devices to provide cordless recharging. One, named Evatran, sells a combination "pad" and "pickup" for between $ 2500 and $ 4000. Another company, named Hevo, sells this for about $ 3,000. The "pad" is attached to the source of the power supply. The "pickup" is equivalent to the plug on the vehicle where one would normally plug in the power supply. Electricity travels through the air from the pad to the pickup.
Evatran was started in 2009 and the started selling its product to the public in 2014.
BMW and Daimler, two of the big German automakers, have announced plans to develop wireless recharging systems, to be installed in a garage or carport.
While it isn't an automaker, Qualcomm is reported to have developed a number products and tools that will be valuable in wireless recharging.
How efficient is this "through the air" recharging? Not quite as good as if a cord is involved, but it's pretty good. When you plug in the power supply, you get about 95 to 99% efficiency. In contrast, when you do it using an induction system, it's about 84 to 90% efficient.
The concept of "one bite at a time" re-charging is actually being used on some bus systems. Milton Keynes, a town northwest of London in the UK, has one of its bus lines outfitted with induction charging. Eight buses on Line 7 of the Milton Keynes system are all-electric, and each of the buses has been outfitted with an induction charging system. When a bus reaches the end of the line and is ready to turn around, it pauses for two to four minutes for a quick recharge, then starts on another bus run. Each bus is recharged this way throughout the day.
The operators of the Milton Keynes bus system say they save about 80 cents/mile by running electric buses rather than diesel ones. This is a combination of lower fuel costs and reduced engine repairs. The eight electric buses on Line 7 run a combined 425,000 miles/year, so the marginal cost savings is about $ 340,000/year.
How much does it cost to install such a system? Milton Keynes uses a charging system built by IPT Technology, a German company, and it costs about $ 130,000/charging pad. Assuming one pad is placed at each end of the trolley line, the payback on any single trolley line is about 9 months, making this a very good investment. The Milton Keynes bus operator is looking to convert other lines on the system. Besides Milton Keynes, such wireless induction charging bus systems are run in Salt Lake City, five cities in California, and European cities such as Utrecht, Genoa, and Turin. Los Angeles plans to install such a system next year.
Wireless induction systems make great sense on bus lines, but could the same concept be applied elsewhere? I think the idea can also be applied to automobiles. Now autos rarely travel along the typical fixed route of a bus, but I think the idea of periodic wireless recharging of autos and other vehicles, the core of the Milton Keynes system, is quite reasonable.
The obvious place to do this is in parking lots. It's become increasingly common to see electric charging stations in parking lots, but it still requires one to attach a cord to the auto or truck. Why not make it so the driver doesn't have to do anything more than park the vehicle in the space? Wireless induction creates the possibility for that. Here's how:
- Imagine that the vehicle is outfitted with a standard "pickup". It could be installed by the automaker.
- Imagine, also, that the parking space has a built in "pad".
- The driver would park the car in the space. He or she could then use a mobile phone app to instruct the pad to recharge the vehicle while it's parked. Charging could be by the minute, with the "charging" charged to the driver's credit card.
- Besides credit card billing information, the app could include instructions about whether the vehicle should be charged if peak load pricing is in effect.
More and more, drivers don't fumble for change on parking meters, choosing instead to pay for parking using a mobile phone app. Why not do the same for electric charging? Pretty much any parking space could be outfitted with a charging pad.
The problem, of course, is who is going to pay to install charging pads? How about the electric utility? They have a natural interest in selling power. But other parties could have an interest in selling electric power if they could be shown a way to make money doing it. So how could someone make money selling power this way?
Anyone who runs a business that has customers driving to store/office might want this. Imagine having your customers park at your place of business, conduct business with you, then have the benefit of getting the auto at least partially recharged. Doctors and dentists should love this. I can't think of a time that I've ever been to a doctor or dentist and it took less than one hour. In the space of one hour, my electric vehicle could at least be partially recharged. Even if it recharges at the rate of a wall outlet, which usually takes 6 – 8 hours to recharge a vehicle, one could at least get a recharge of about 1/8 the total in an hour. Typical electric vehicles now have a range of at least 250 miles, so one hour of recharging should provide at least an additional 30 miles. If it's a fast recharger, it could easily completely re-charge the vehicle.
Why might a business want to make this type of investment? It might do it simply as a way to attract customers, but a more likely reason would be as a way to generate additional revenue. The company could charge customers for electricity by the minute, the rate depending upon how fast the recharging system operates. Presumably, it would charge a premium over what the driver would pay for electricity if he or she did the recharging at home, but because this is a convenience, most likely the driver will be willing to pay a premium.
Could wireless re-charging of vehicles be a viable business? If re-charging pads can be sold for $ 2500 to $ 3000, I believe one can easily create a viable business with as little as $ 4.00 to $ 5.00 in revenue per charging pad per day. This would be in addition to the cost of the power. Assuming the charging station could be priced at $ 2.00/hour plus power, it would only need to be used 2 to 2 ½ hours each day. Would drivers pay $ 2.00/hour to use such devices? I believe they would, especially if they're concerned about running out of power. Simple convenience suggests this makes a lot of sense.
Alternatively, the electric utility might install these charging pads, then pay some type of rental fee to the owner of the parking lot. Again, this could be a revenue opportunity for both the parking lot owner and the electric utility. An electric utility might want to make these available, even providing the power for free at certain times of the day, simply to help reduce the load at other, peak times. It's been reported that utilities in California are now experiencing excesses of power during the day due to solar installations, so providing free charging at certain times might benefit more than just the driver.
Using the recharging service would be completely optional to the driver of the auto. They key is to create a convenient, simple experience for the driver. The ideal scenario is for the driver to park the car, the driver to use an app on his or her phone to instruct the charging device to recharge. It might even be done more or less automatically.
The core idea here is convenience and user experience. The more that it can be made easy, the more likely is it for drivers to want to adopt electric vehicles. The induction concept provides another way for the driver to avoid running out of power, and also a convenient way to add power.
Induction based wireless charging will provide a convenient way to overcome the problem of "range anxiety", the fear of the car running out of juice. It should provide one more way to make electrics the vehicle of choice in the days to come.