BOULDER, Colo. -- For proponents of battery electric vehicles (BEV), the development of a public charging infrastructure has been frustratingly slow. And the latest technology that promises to speed up that development is facing headwinds of its own, according to a recent webinar by clean-technology market research firm Navigant Research.
DC Fast charging is an electric vehicle supply equipment (EVSE) technology that can provide a full charge to a BEV in less than one hour, compared to lower-voltage level 1 and 2 home and public charging stations, which can take several hours.
It also could make the best business case for public EVSE hosts--the faster the charge, the faster the ROI--and it could also influence the design of future BEVs. "More frequent, rapid charging could encourage automakers to install smaller, less expensive batteries on vehicles," said presenter John Gartner, smart transportation program director at Navigant, noting that the price of the battery accounts for most of a BEV's premium versus traditional vehicles.
"The challenge for companies looking to offer fast charging in their specific area is where to place the equipment, since BEV sales will not really be uniform across any geography, with concentrations in larger, urban centers," said Gartner. According to Navigant projections, annual BEV sales will grow nearly tenfold by 2020, with the strongest sales growth in China, Japan, Germany and the United States. Currently, only 15.5% of BEV sales come from North America, according to Navigant, with Western Europe and the Asia-Pacific region expected to contribute 80% of the market through 2020.
"North America won't grow as fast because of greater interest in plug-in and extended-range vehicles in the U.S., as many American drivers do not like to be constrained in their driving distance and they prefer having the option of a secondary power source of a fuel tank," said Gartner.
While Navigant believes one public DC fast charger per nine BEVs is a "sustainable" ratio, there is currently only one charger per 170 BEVs in the United States. "Vehicle sales have gotten a bit ahead of infrastructure," said Gartner. "This current undersupply of charging infrastructure indicates an opportunity for locations to host charging infrastructure."
However, one of the biggest barriers to infrastructure development is the high cost of the DC fast charging equipment, which is continuing to fall but currently sits around $16,000 per unit, according to Navigant.
There is also an infamous standards conflict for BEV fast-charging connectors, with Japanese BEV automakers embracing the CHAdeMo standard, while European and American car makers plan to adopt the new SAE Combo connector standard. BEVs must have a CHAdeMo compatible socket to charge from an EVSE with a CHAdeMo connector, and similar constraints would apply to BEVs with an SAE Combo compatible socket. Webinar presenters compared it to the VHS and BETA videotape technology tussle of the 1980s, and expected it to take five to 10 years for the industry to finally agree on a final standard. GM's Chevrolet Spark will be the first vehicle on the U.S. market this year compatible with the SAE connector.
Finally, there is the sticky issue of demand charges, which hosts can incur from their utility if the high-current, 500-Volt DC fast charging units draw during peak times. One possible solution is new "medium Fast DC charging" EVSEs that are rated at 20 to 30-kW and can charge a BEV battery up to 80% in one hour, and draw less power.
It's a critical issue to hammer out if the charging infrastructure is to expand, and one that hinges on growing the BEV fleet to bring down costs for EVSE hosts. Consider that a DC Fast charger seeing only one charge a month can incur a cost per vehicle of more than $800, after factoring in energy costs, the meter charge and a hefty demand charge. If up to 500 BEVs visit that EVSE per month, the cost falls to $3.80 per vehicle.
"It's a huge marginal cost impact for operating DC Fast chargers," said co-presenter Garrett Beauregard, executive vice president at ECOTality Inc., manufacturer of the Blink and Minit EV charging stations. "We need to think about how many charge events will a charger see in a month so we can start to amoritize that demand charge and really bring those costs down to a reasonable range where you can have a business model."
The real trick, said Beauregard, is to figure out how to satisfy customers' needs, which don't necessarily coincide with utility demand rates. "How do we find a happy medium that allows for an ongoing business model that also gives the customer what they need, which is the energy to keep driving?"
Click here for a replay of the Navigant Research webinar "Fast DC Charging for Electric Vehicles."
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