Wireless Charging: Insights from EV Roadmap 8 Oregon
04 Aug 2015
There was a question and answer session "Wireless Charging: Emerging Business Models" at EV Roadmap8 Portland Oregon USA 30 July 2015.The panel consisted of Jeremy McCool of Hevo Power, which retrofits wireless charging, Jeff Muhs of WiTricity with key patents and Wesley Smith of WAVE installing large vehicle solutions. They also talked to IDTechEx afterwards.
The panel saw many positives for WC making it the inevitable end game in their view. It is space saving and not ugly like manual charging stations. It is the only sensible option for shared cars and autonomous vehicles. In urban environments, charging by overhead gantries (eg Sinautec, ABB and Proterra buses) is often banned or not viable so WC solves the problem.
Less convincingly WAVE thought it may become mandatory for warranty of a vehicle because improper charging is possible for contacted charging - presumably meaning deep discharge and neglect that would not occur with independent top ups from semi-dynamic and dynamic charging without driver involvement. All felt that efficiencies and costs are now comparable to those for contacted charging. Prospects are even better because, "Power electronics will continue to improve in size, cost and efficiency faster than batteries". Indeed WAVE has been increasing the kW handles by four times in 18 months with 250 kW charging expected soon. All agreed that there is no limiting physics with the power of wireless charging. WAVE is even talking to ship companies about 1 MW charging. "Heat will need to be managed but that is OK".
Contrast bus companies with plug-in where special staff are hired when bus drivers refuse to handle electricity with wet hands in the open. This is an identified issue with car drivers too and in cold climates, "contact charging is a disaster". On the other hand, WAVE has two WC systems in roads surviving salting and snow ploughs in cold parts of the USA. Visual alignment is used as in the picture below and it was not said what is done when snow covers the guide lines. People can walk over them safely.
MvCool advises that warranty and safety issues of retrofitting are manageable and WC is inherently lower cost and far more attractive to consumers than contacted charging. The panel expressed the view that OEM car manufacturers will be fitting WC as standard in up-market models from 2017. The standards issues for open systems are not fully resolved but the situation is nothing like as bad as for phones and the like with two competing standards. A measure of collaboration between SAE, IEC, ISO and so on is occurring on this. Indeed, Wesley Smith of WAVE told IDTechEx that industrial WC standards will be no problem at all because it will simply be that the first big rollout will establish a de facto standards that will later be formalised.
No one was pretending that dynamic and semi-dynamic charging is imminent but it was convincingly argued that there is facts based range anxiety with industrial vehicles converting to pure electric unlike the largely imagined worries of car drivers. See below.
Range difficulties with pure electric industrial vehicles
Source IDTechEx picture
All agreed that very few WC are out there on vehicles and getting ones to fit is an issue. They said Conductix Wampfler in Belgium has two vehicles fitted there, two in the UK and two in Italy. Bombardier has two on trial. This represents little change over many years.
The current design of electric buses almost always involves large batteries travelling around and the panellists questioned whether this will survive in the longer term because inductive top up will be seamless. Indeed they noted issues with who pays for any form of charging because there is no payback. However, Wesley turned this on its head by suggesting that utilities desperate to stop the peak time extra load of 2.7 GWh of power going into the bus batteries of California for example would install, operate, fund and own top up inductive charging to level their grid loading.
How to compete better
Asked specifically how the WC industry could more effectively compete, the panel said that it must improve the customer service model over plug-in. It must get higher power for buses etc because although there is no theoretical limit, to SAE the limit is about 20 kW at present. At $1000/watt the WC option is argued to be comparable to plug-in costs but these were three organisations selling the technology. IDTechEx does not get that message from others. Anyway the panel said clearly lower costs than contacted charging and clearly comparable efficiency at end-to-end 85% or more would boost adoption. The WC industry must get over the message of better appearance, practicality and cost of ownership, even smaller parking lots possible with WC. Safety and standards must be accepted by all. Good news is that Toyota has licensed the WiTricity resonant (longer range) technology, all agreeing that this is necessary for vehicles unlike the situation with phones etc where close coupling is vying with resonant though both are inductive coupling. These enthusiasts all believed that the lack of problems with metallic wrapping blowing onto the coils, animals getting between the coils, water and so on are all accepted by the major car companies as non-issues now. One proof cited was that fact that Toyota licensed the WiTricity system.
The panel considered transit, notably buses are the easiest entry point for WC. They noted in passing that buses are a much more compelling case for pure electric powertrains anyway because the user experience in cars is modestly improved whereas in buses you can hear what people are saying for the length of the bus, the silence is dramatic.
In a parallel session on EVs beyond cars, Proterra, the manufacturer of pure electric buses shared the following perception of the place of inductive charging today, noting that its gantry system charges at 400 kW so they need more power from inductive alternatives.
Proterra view on WC vs other charging of buses today.