There are sectors of the transport system, such as buses and heavy goods vehicles, which have proven challenging to electrify due to their high energy demands. Dynamic Wireless Power Transfer (DWPT) is a technology which has the potential to help these use cases decarbonise by extending the range of battery electric vehicles by powering the vehicle or charging the battery while it is in motion. This proposal aligns with one of the three focus areas from our Innovation Forward Plan: Electrification of Freight. This project will investigate wireless dynamic charging infrastructure and its impact on our distribution network. The project will produce models that will accurately assess the impact of a roll out of this type of technology across our license areas.
This project will assess the feasibility of deploying DWPT technology on UK roads and the electrical impact on our distribution network. This technology is a small continuous charging strip that is laid beneath the tarmac on major trunk roads. The electrical impact of this technology is not yet understood, as it would require many connection points across the length of charger, and there would be several challenges to understand such as earthing arrangements.
As part of this project, a scalable and transferrable model to evaluate the impact of DWPT on the energy network will be created. The project will also produce a set of electrical values which will be incorporated into the new WPD planner’s tool. This is a key deliverable and will be shared with all RIIO licensed UK DNOs for their own use. The project can be broken down into the following work packages:
WP1 – Project Management – Set up of project and the maintenance of all the project management documentation.
WP2 – Technology Review – Review of current continuous charging systems & wireless systems worldwide, led by Cenex.
WP3 – Power Modelling – Coventry University will model the proposed technology on our case study network in Coventry, and asses electrical impact.
WP4 – Demonstrator Evaluation – Building on WP3, Cenex will include traffic data to provide accurate usage profiles for the technology and look at the viability of the technology including validation.
WP5 – Dissemination and Reporting – Final evaluation reports and dissemination to industry. This includes the transfer of deliverables into BaU.
Coventry City Council will lead the project with support from WPD and a consortium of partners: Cenex; Coventry University; Hubject; Midlands Connect; National Express; Toyota Tsusho UK and Transport for West Midlands.
Benefits
The project will benefit all energy network licensees who will be able to better understand the impact of DWPT technology on the energy system, and by incorporating the findings of this feasibility report into BaU planning tools, as well as having a forecast of the use and demand of this system across the WPD area.
By having this feasibility study completed, it will ensure the efficient connection of wireless chargers to the network, with complex and technical issues already resolved. This will support the on-going commitment of achieving net zero by 2050.
NIA Project Registration and PEA Document 2021-07-10 9_56 (95.8 KB)
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NIA Project Registration and PEA Document (86.4 KB)
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NIA_WPD_055 (21-01-2021 16-00-54) (47.8 KB)
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NIA_WPD_055 (28-01-2021 14-29-14) (47.7 KB)
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project-difference (08-04-2021 15-06-43) (9.0 KB)
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project-difference (08-04-2021 16-35-22) (9.0 KB)
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WPD_NIA_055 (30-11-2020 17-58-09) (47.8 KB)
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Learnings
Outcomes
Work package two found that there were eight other projects which have demonstrated this technology, but only one supplier worldwide. It also found that there would be work needed for it to comply with all the existing standards which surround things on highways, electromagnetic emissions, and cyber security. The third work package was a modelling task based on a case study location. This found indicative demands for a vehicle passing over a DWPT system, and then combined this with the traffic modelled in the area, the expected state of charge, and how that would vary throughout the day. This found that for various scenarios, it would add to the demand at the evening peak as most people are travelling home from work with a car that would be at lower charge than in the morning. This means it will not help us as a DNO with our flexibility aims, in a way that conductive charging could. The fourth work package looked at the business case from the charge point operators’ point of view, to determine if a DNO should expect to see these on the network soon. This found that the best business case was marginal at best, which is to fit the vehicle receiver coils to Heavy Goods Vehicles, and lay DWPT on motorways. This is because HGVs spend a lot of time on motorways and fitting DWPT there would amplify the effects of the installation. The case from the DNOs point of view for this technology was that it would allow us to provide charge to HGVs in a more distributed manner, and allow us to install DWPT in areas which currently have spare capacity and avoid the need for expensive reinforcement. However, there are numerous technological and regulatory barriers to its uptake in the UK, and as a result, we are not expecting to receive connection requests for these in the near future. A Draft paper was submitted for peer review, titled Determining the social, economic, political and technical factors critical to the success of dynamic wireless charging systems through stakeholder engagement https://www.mdpi.com/journal/energies/special_issues/Wireless_Transfer
Lessons Learnt
DWPT operates at frequencies between 10 and 100 kHz, often centred on 85 kHz, and requires AC/DC and DC/AC converters to increase the frequency of power supplied, this could have an impact on power quality depending on the efficiencies and how the technology is being utilised.
Variations in air gap, lateral alignment and longitudinal alignment, mean that DWPT systems must be designed to give acceptable power transfer efficiency when misaligned.
DWPT deployments should adopt a modular design to allow for scalability and reduce distribution network impacts. All DWPT solutions consist of a Management Unit (MU), Ground Assembly (GA) and Vehicle Assembly (VA) for which the MU and GA is controlled by the installer of the coils.
The take up of this technology will depend heavily on vehicle manufacturers adopting this technology and installing VA (Vehicle Assembly) or receiver units on their vehicles.
A total of eight DWPT demonstrations or deployments have been identified around the world with most projects focusing on supplying power to heavy vehicles such as trucks or buses. This is significant as at this stage of the technology lifecycle, it is not deemed feasible for privately owned passenger cars.
ElectReon is the only active participant in the DWPT market at present.
Early learning has determined that the lack of comprehensive standards across all the elements of technology, installation and use of DWPT is currently a risk for future deployment. To avoid problems of interoperability, tailored standards on the type and placement of receiver coils, compliance with roadway construction and safety regulation to standards of service, information sharing, data collection and payment will be required.
Power Quality – DWPT systems are made up of various electronics that will have an impact on the power quality at the point of connection to the network. Impacts such as harmonics are discussed within the report but can only truly be detailed using a live trial.
The cost to install DWPT is at a best case scenario three times more expensive than traditional conductive charging. This is taking into account the most likely scenarios and comparing with traditional methods. This is a significant barrier to wide scale rollout and for DWPT to be realised in the UK either the costs of purchasing and installation will need to be reduced or the costs per kWh will increase significantly to outweigh any potential savings through reduced battery sizes.
