Range Confidence: Charge Fast, Drive Far, with your Electric Car

By David Herron

Long range electric cars, sales rate, the need for more fast charging

By now the message of this book should be clear: We need more fast charging.

Between late 2016 and 2020 several automakers have promised to begin selling 200+ mile range affordable electric cars. The price, $35,000 or so for a 60 kiloWatt-hour electric car with 200+ mile range, is a big improvement over what we have today (January 2016). If only because it's "more bang for the buck", these cars will make a big positive impact on electric car sales.

The 200 mile range should evaporate the range anxiety consideration. As a result, there should be an upswing in electric vehicle adoption. Lots of research over the years have pointed to a minimum 150 miles range as a threshold for widespread EV adoption.

By looking solely at the range, these buyers may miss a problem. Unless there's a matching buildout of fast charging stations, these longer range electric cars will not satisfy what the people think they're buying.

Many of these new electric car owners are unlikely to be well experienced with electric cars. Instead many of them will have been sitting on the sidelines waiting for a longer range EV, and they may have expectations similar to the gasoline vehicle experience. Namely, expecting to drive long distances using fast recharging along the way.

By their nature, the longer range electric cars will amplify that idea. With the longer range, these cars will naturally be able to fulfill a larger proportion of our trips. It will be attractive to bite the bullet and go fully electric, for those families which kept a gasoline car for long trips.

With the existing fast charging infrastructure, there's likely to be some disappointment. Except for the Tesla Model 3 owners who'll be using the Supercharger network and its excellently planned infrastructure. An example of that disappointment was an article by a newly minted Chevy Bolt driver in March 2017, discussing the trip she and her daughter took from San Jose to Los Angeles, which she described in horrible terms simply because of a few difficulties getting charging when needed. [GreenCarReports] While she planned the trip fairly well, she missed a few opportunities to charge which would have improved the trip's success.

But the bigger point is insufficient fast charging infrastructure to handle an influx of more electric car drivers.

The nature of longer range electric cars

When typical electric cars had 80ish miles electric range, it was a reasonable assumption to limit our trips to an oval shaped area surrounding our home base. The slow recharge time at 3 kiloWatts coupled with relatively short range means a longer range trip would be tedious to say the least. But we're moving into a new era, with new capabilities at the same price point.

When we analyzed several long range trips using today's charging infrastructure (May 2017), we saw how it's conceivably possible to take a longer range trip using an 80ish mile range electric car (with fast charging) but that it would be much easier in a 200 mile range electric car. For example the distance from St. Louis to Chicago has a handful of charging stations along the route. The distance between them is long enough to be risky with an 80ish mile EV, and fairly simple with a 200+ mile range EV.

The driving range roughly determines your driving horizon. The 80ish mile electric car is on a shorter leash than the 200ish mile electric car, meaning owners of the latter can easily drive further. The result will be a feeling of greater freedom, simply because it has a longer driving range.

In other words, we should expect a natural tendency for long range electric vehicle trips.

Can't get no satisfaction?

What happens if that natural increase in long-range electric vehicle trips is met by insufficient fast charging?

Taking a long trip requires fast recharging, and this is true of not only electric, but gasoline or diesel vehicles. Why? Making as good a time as possible requires ... what? Fast recharging or refueling, as the case may be.

Stories like the one run by Green Car Reports in March could become commonplace ... and then what? Would the population sour on electric vehicles ("can't find any charging stations")? And would this project of widespread EV adoption be threatened?

The Tesla Supercharger network has (so far) been built with exactly to support long-range road trips, and not so much to support urban dwellers driving around an urban area. At least Tesla owners will find satisfaction, even if owners of other brands do not.

Why EV Fast Charging is required for widespread electric car adoption

If electric car owners owners are trapped to drive within a radius of their home, EV’s will never replace gasoline powered vehicles. The competing transportation fuel, gasoline and diesel, may continue being seen as offering the compelling refueling experience. That may keep people hooked on gasoline or diesel.

The tendency to focus on the driving range – when will we have an affordable 200+ mile range electric car – misses the importance of fast charging. What's important to keep in mind is effective trip speed including the charging time. Understanding charging rates and effective trip speed The faster the recharge time, the faster the effective trip speed.

To make clear the difference between different systems (approximate recharging time for 300 miles of range):

  • 6 kiloWatt electric car charging – 300 miles range requires at least 12 hours recharging time
  • 50 kiloWatt EV charging – 300 miles range requires about 3-4 hours recharging time
  • 120 kiloWatt EV charging – 300 miles range requires about 1 hour recharging time
  • Gasoline or similar liquid fuels, Hydrogen, flow battery, battery swap – 300 miles range requires 5 minutes

While you could make a 3000 mile road trip with a 6 kiloWatt charging speed, you wouldn’t enjoy the experience because of the 120 hours of recharging time required. But 3000 miles with 120 kiloWatt charging is a breeze, requiring only 10-15 hours or so of recharging time. You’d need to take at least that much time for human needs like potty breaks and meals and sleeping.

Research shows that fast charging gives the feeling of freedom

Even though the typical driver only rarely takes Road Trips, many judge prospective cars by their Road Trip capability.

Let’s look at research presented at the PlugIn 2010 conference by Mr. T. Anegawa of TEPCO (Tokyo Electric Power Company). He showed the response of electric car drivers in Japan when the CHAdeMO network was first rolled out in 2008.

This image was derived from Anegawa-san's presentation, and reminds us the desired charging rate depends on the driving scenario we’re in. In some cases a slow charge speed is alright (long term airport parking could take several days for the recharge), in other cases a medium charge speed is okay, and in certain circumstances (like Road Trips) the charging speed has to be as fast as possible. See What charging rate do we need? “As fast as possible” isn’t always what’s needed

Typically drivers travel 40 miles or less per day. This means the number of trips requiring greater range are rare, for most people. Of course certain individuals have greater needs, or lesser, we're talking about the average driver.

This key observation by Anegawa-san demonstrates the value of fast charging. DC Fast Charging was first deployed in Japan in July 2008, long before the Nissan Leaf was first delivered in the USA. Prior to that date electric car drivers were timid about driving. Afterwards the mere existence of the fast charging network gave drivers the confidence to drive their cars more often and for longer trips.

In this last slide Anegawa-san tries to get at the economics of large scale electric vehicle charging station deployment. This shows an estimated cost of charging stations to support 1 million electric cars.

The two sweet points are the 1 kiloWatt line cord charger sold with the car, and the 50 kiloWatt (or more) DC fast charging stations.

The first is an inexpensive choice for deployment at the car owners home. Millions of these will be sold, at least one per electric car. An overnight charge with such a unit gives enough driving range to satisfy typical daily driving needs. This truism is demonstrated by the fact that this is what the majority of electric car owners do for charging at home.

Fast charging systems do not need to be ubiquitously deployed. Anegawa-san suggests a couple thousand are sufficient to support a population of 1 million electric cars. It's thought installation costs are $20-50 thousand for DC fast charging stations.

The cost he gives for in-vehicle 3 phase AC charging has been disproven with the Renault Zoe. He claims it incurs a huge vehicle cost, but the Renault Zoe is an extremely affordable electric car. Their cost-savings trick was to use the electric motor windings in the charging system, reducing the cost while implementing a 43 kiloWatt 3 phase AC fast charging system. The Zoe is one of the most popular electric cars in Europe.

On the other hand, Anegawa-san's estimate for the cost of battery swapping stations seems spot-on given what happened to Better Place. That company implemented the battery swapping approach, offering electric car drivers a 2 minute recharge time. That is, by swapping in a fully charged pack the car can quickly drive away fully charged. Recharging the depleted pack will of course require some time, without impacting the car driver. Better Place went out of business in part due to the high expense of building battery swapping stations.

Hydrogen fuel cell vehicles have a similar very fast recharge time – because it’s “just” a matter of refilling an on-board compressed hydrogen tank. But, (longtailpipe.com) the hydrogen refueling infrastructure is expensive, because stations cost $2 million apiece. By contrast, DC Fast Charging stations cost a fraction of that amount.

What about ethanol or other biofuels? They can slot right into the existing liquid fuel system, and be dispensed at gasoline stations just like gasoline or diesel. Surely their refueling infrastructure is inexpensive, as is the on-board equipment in the cars. I’m sure that’s true – however, biofuels have a hidden cost because of the amount of land required to grow the fuel. (greentransportation.info) Where it’s possible for an average house to hold enough solar panels to power not only the house, but a couple electric cars, try to do the same with Corn Ethanol and you require nearly 3 acres of corn to fuel one car. Try to fuel the entire American vehicle fleet with corn ethanol, and you’ll need to find 300+ million acres of land – more land space than all of California – just for the corn fields.

In other words the most cost efficient method for non-fossil-fuel rapidly recharged vehicles is DC Fast Charging battery electric cars. Every other method is much more expensive than this.

Cost is one limiting factor for charging infrastructure deployment. It's a business concern, the more expensive the equipment the less feasible it is to build enough to support refueling a large fleet. To make a significant impact on climate and environmental issues, there must be a large fleet of zero emission vehicles.

Which of the fast refueling technologies will support a large zero emission vehicle fleet? That's DC Fast Charging.


Range Confidence is Copyright © 2016-17 by David Herron

Long range electric cars, sales rate, the need for more fast charging

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