Competing Charging Standards Could Threaten Adoption of Electric Vehicles

Power Politics: Competing Charging Standards Could Threaten Adoption of Electric Vehicles

Can a new, global standard take on an existing, widespread fast-charging system? 

Plus, a timeline of electric-vehicle milestones

By Nick Chambers  

To most Americans electric cars are as new a concept as the first combustion vehicles were to horse-and buggy-drivers in the early years of the 20th century. But to the organizations around the world that have been working to make modern electric cars a consumer reality, it has taken decades to get to this point. In fact, the electric car industry is old enough now that it has developed its own internal conflicts—the biggest of which centers on vehicle charging. Unfortunately, engineering groups and consortiums are developing different standards for a quick jolt, and if the differences are not resolved, the burgeoning electric vehicle industry may stumble.

The goal, of course, is to enable electric-car owners to charge their vehicles as effortlessly as they would fill up at a gas pump. Common standards are what makes that possible. In the U.S. the organization tasked with developing these charging standards is the Society for Automotive Engineers (SAE). In January 2010 the SAE approved the so-called J1772 standard governing slow- to moderate-speed electric car charging. Every major electric car manufacturer, and most start-up ones as well, have committed to using J1772 in their existing and future products. In 2011 more than 15,000 of these J1772-compatible stations are planned for installation in early deployment communities around the U.S.

But the J1772 standard accounts only for charging at relatively low speeds. On a 110- to 120-volt circuit it can add about eight kilometers of driving range for every hour of charging, and on a 220- to 240-volt circuit, it can sustain between 24 and 100 kilometers of driving range for every hour of charging (depending on individual vehicle and station specifications).

To create more parity between electric and combustion engine cars, the industry has been developing so-called DC fast charging—which can nearly top off an electric car's battery pack in less than half an hour. (The typical range of a fully charged car is 160 kilometers.) This type of charging requires a gas pump–size station attached to an industrial power supply. Although the size and voltage make DC fast charging unsuitable for the home garage, it should be sufficient at commercial charging stations.

Two competing standards

A few pioneers have forged ahead with this fast charging, with Nissan and Mitsubishi taking the lead. Yet the standard they have chosen—called  CHAdeMO and developed by a consortium of Japanese companies—will soon face competition from another standard under development by the SAE.

The SAE expects to have its DC fast-charging standard ready within nine months, and carmakers and station manufacturers should have equipment samples in the fall to begin their internal testing, says Peter Byk, an SAE engineering specialist. The final standard should come by the end of this year and no later than the first quarter of 2012.

It will be at least 2013 before the SAE standard starts showing up in consumer vehicles. In the meantime there will be nearly 700 CHAdeMO stations in Japan, 500 in the U.S. and 300 in Europe by the end of 2011. By the time the first SAE–compliant DC fast-charging–equipped cars hit the road there could be perhaps thousands of CHAdeMO stations in the U.S. alone, according to John Gartner, a senior research analyst with Pike Research and author of an upcoming report on the state of DC fast-charging technology around the globe.

"As Nissan and Mitsubishi start selling electric cars in mass volume, they want to provide the functionality that DC fast-charging entails, so the initial products to hit the North American market went with what was the closest available standard and that was CHAdeMO," Gartner says.

Nissan began selling its LEAF all-electric car last November and has plans to sell more than 200,000 of them a year by 2013. Mitsubishi began selling the all-electric i-MiEV in select locations around the globe last year and will start selling it on the North American market at the end of 2011. Adding DC fast-charging capability to both of those vehicles is an extra cost option at the time of purchase, and many consumers have opted for it, especially on the West Coast where CHAdeMO infrastructure will be widespread.

Given the sales targets of both companies, the potential for CHAdeMO adoption could be on the order of tens of thousands to perhaps more than 100,000 vehicles by the time the SAE fast-charging standard is available in its first consumer electric vehicle.

Universality has its benefits

The current SAE fast-charging design calls for a hybrid combo that would be backward compatible with the J1772 standard but would also support DC fast-charging through a universal cable.

A universal charging standard has benefits in terms of cost savings and ease of engineering, and according to some, the SAE standard also has technical improvements over CHAdeMO designed to make it future-proof and safer to boot. BMW, which in 2013 will start selling their first mass-market all-electric vehicle, the i3, has been working in close collaboration with the SAE to develop the universal charging standard.

"We have a lot of problems with different standards around the world already," says Josef Krammer, team leader for charging systems at BMW. "We deliver our vehicles everywhere, and it's very difficult if we have to adapt our charging systems for each region."

According to Krammer, although CHAdeMO works, its major drawback is that it requires a second charging port in addition to the 110- to 240-volt AC port—which drives up both space and cost requirements. In addition, SAE's Byk says that CHAdeMO uses an older communication standard not expected to work well withcoming smart grid technologies. Also, it is less safe because instead of relying on the physical contact with the ground to shunt short circuits, it relies on a ground fault interrupt, which monitors the line for imbalanced loads and shuts it off if it senses a surge. It is like the difference between having an alternate pipe for the sewage to drain into (physically grounded) and having a way to shut off a burst sewage pipe (ground fault interrupt).

Gaining a competitive advantage

Even so, Nissan says that CHAdeMO meets the needs of electric car drivers now and into the future. "As of today, CHAdeMO is the only proved DC quick-charging system," says Hideaki Watanabe, corporate vice president, Nissan Motor Co. "We are working with our partners to deploy CHAdeMO throughout the world, and we didn't want to take a 'wait and see' approach. We wanted to be a proactive player and deploy fast charging solutions now."

The existence of multiple standards may not actually be a big deal, says Pike Research's Gartner. "The real losers are the carmakers who are waiting to provide fast-charging support while their Japanese competitors increase market share," he adds.

What effect will it have on adoption rates?

Gartner envisions a future where both standards exist as parallel options. "Because of its penetration rates CHAdeMO won't ever become obsolete," he says. "Just because SAE says they are making a global universal standard doesn't mean the Japanese manufacturers are going to switch." As Gartner sees it, manufacturers will want to take advantage of the infrastructure that is already in place. "If there are already hundreds of stations on the ground—soon to be thousands—why wouldn't a manufacturer choose that option?" he asks.

But BMW does not think this parallel-option scenario will work. "Over the long term, I don't think that multiple standards can co-exist in one region," Krammer says. He cites the need for uniformity between all vehicles and convenient consumer access as the major reasons for this. SAE's Byk agrees, and says that the convenience of universal plug format, coupled with the majority of manufacturers adopting it in the long term will likely force the market to move away from CHAdeMO.

Regardless of whether one DC fast-charging standard wins, in the short term the controversy is sure to cause some confusion in marketplace, although Gartner does not think it will have much of an effect on adoption of electric cars. "The typical consumer still can't distinguish between hybrids and electric cars," he says. "If that basic distinction is still missing, then the DC fast-charging issue is one that means very little in terms of market adoption rates of electric cars in general."