Wireless charging is the secret to expanding EVs

Urgent action is needed to increase the ease of owning and operating electric vehicles (EVs), both light and heavy duty, if Aotearoa New Zealand’s vehicle fleet is to change in time to meet the required targets for greenhouse gas emissions set by the Climate Change Commission.

The Government’s recently announced discounts of up to $8,625 are a positive move but technology changes are also imminent that should smooth the way to going electric.

To help alleviate any purchasing concerns of operating an EV, extending their travel range is critical. After all, most consumers and fleet owners don’t want to constantly worry about running out of power, so for them the easiest way to avoid that drawback is to stick with petrol and diesel vehicles in the short term.

Although advances in battery technology are helping to reduce concerns and the sales barriers they create, equally important is work being done in New Zealand to help make EVs mainstream by creating wireless systems that can be integrated as part of a road and perform over expected lifetimes in locations that make economic sense.

This work at the University of Auckland, with the Robinson Research Institute at Te Herenga Waka—Victoria University of Wellington and GNS Science, is all about removing the plug-in and range anxieties associated with owning an EV. Instead of plugging in vehicles, drivers can simply park or drive as usual, but over a coil buried in the ground. This means the vehicle can be ‘connected’ to the grid without wires and can be charged when stationary or on the move with a process that happens automatically.

Wireless charging isn’t a solution in search of a problem. Just the opposite: cutting the cord eliminates multiple problems, starting with the obvious one of never having to worry about forgetting to plug in.

For example, it’s easy for parents juggling groceries and a toddler to forget to plug in when they arrive home or for them to leave the choice of plugging in until later—an oversight they don’t realise until it’s time to leave for daycare and work.

For fleet owners, the forgetfulness problem scales up, such as lost productivity when employees wind up stranded on the side of a road.

For consumers and fleet owners alike, wireless also eliminates the expensive problem of connectors damaged by debris and weather infiltration, and the need to plug in outside in all weather conditions.

Other benefits are less obvious.

Making charging easily available and simple to use (without having to do anything other than park or drive normally) means people will take advantage of it more often. Without this, many consumers will rely on plugging in at home. In developed countries, electric utilities look at consumption history to assume each household will use a certain amount of power—about 2kW, on average—and build their infrastructure accordingly.

Now fast forward to, say, 2030, when EVs are more common. Suddenly there are many households with one or two EVs that could consume 10kW or more at night, while commercial premises could have significant-sized EV fleets. To accommodate the demand, utilities would have to upgrade their neighbourhood transformers and other infrastructure—something that takes a lot of money and lead time to implement.

Wireless charging can significantly reduce the need for those upgrades by spreading demand over a larger amount of geography and time. Today, vehicles are charged at home or, in the case of fleets, at the owner’s place of business. Tomorrow, they’ll be charged in various additional places, including at work, at the store, on the street and in places of interest (such as at the beach and parks, which are often weekend locations and if some distance away raise natural concerns over the range of the EV). Solar and wind can power wireless charging stations because vehicles will use them only for short periods to top-up rather than for hours or overnight.

For commercial fleet operators of medium- or heavy-duty vehicles, despite battery improvements the weight of the battery pack required to enable large payloads and long range are of concern, with the charging time needed at truck stops. With wireless charging, smaller battery packs can be used by taking advantage of future in-road systems to improve the vehicle efficiency and reduce downtime.

Many, if not all, of the automotive manufacturers have spent the past several years working with their suppliers evaluating, developing and refining wireless charging technologies. These systems have been successfully integrated and tested on a number of different vehicle platforms: Renault Fluence; Nissan Leaf; BMWi3; BMWi8; and Honda Accord.

In late 2020, a number of light-duty vehicle wireless charging standards were completed globally, targeting up to 11kW. These standards ensure developed systems will meet all safety regulations and will be designed to ensure any vehicle can charge on any ground pad irrespective of their design, manufacturer or the vehicle to which they are fitted.

And the good news is standardisation efforts have ensured seamless power transfer is now possible over standard airgaps with high efficiency (typically over 90 percent, which is only a percentage point or two lower than a plug-in system).

Heavy-duty standards, targeting significantly higher power levels for buses and trucks, are presently being developed, with safety and seamless high-efficiency power transfer at common charging stations as the focus.

This standardisation process is expected to be shorter, given what has been learned from the light-duty standards, and because selected proprietary heavy-duty wireless charging systems have been in place and tested in Europe, the US and Asia for more than a decade, showing the technology can now be scaled to meet heavy transport demands.

By early 2022, expect to see wireless charging emerge as an option: initially on luxury light-duty vehicles, as is the case with just about every new technology, and then steadily down market. Some fleet owners could be early adopters even though they don’t buy premium vehicles—for example, taxi companies were among the first and biggest buyers of hybrids. Higher power levels will become available over the following five years as heavy-duty standards develop.

Dynamic electric vehicle charging (charging on the move), as a potential future application of this technology, has also been successfully trialed. Present research is focused on designing systems that can accommodate all modes of transport, with many different power demands and ground clearances. This is expected to become available within a decade as EV vehicle numbers increase. Initial applications include slow-moving traffic at taxi ranks, but as these systems mature and cost is reduced installations with lanes on highways will enable power transfer at highway speeds.

So while solutions are ready to roll out for light-duty vehicles, significant research is now targeting solutions for commercial and heavy-duty vehicle fleets to encourage electrification, given present heavy-duty vehicles are only 6 percent of the vehicles on the road but emit 23 percent of transport carbon emissions.

Wireless power, a technology pioneered in New Zealand, and successfully commercialised in industrial applications and for consumer electronics, is now having a global impact that can make life better, easier and lower cost, and at the same time help fight climate change by contributing to decarbonised transport systems.

Professor Nick Long is director of the Robinson Research Institute at Te Herenga Waka—Victoria University of Wellington. His research includes magnetic materials for wireless power transfer.

Professor Grant Anthony Covic is in the Department of Electrical and Computer Engineering at the University of Auckland. He has been researching wireless power transfer for more than 25 years and is the co-chair of the interoperability sub-committee within SAE J2954 focusing on wireless charging standards for electric vehicles.

Dr Doug Wilson is in the Department of Civil and Environmental Engineering at the University of Auckland. His research includes placement of wireless power within pavements to ensure system robustness.

Read the original article on Newsroom.