An electric road, eroad, or electric road system (ERS) is a road which supplies electric power to vehicles travelling on it. Common implementations are overhead power lines above the road, ground-level power supply through conductive rails, and dynamic wireless power transfer (DWPT) through resonant inductive coils or inductive rails embedded in the road. Overhead power lines are limited to commercial vehicles while ground-level rails and inductive power transfer can be used by any vehicle, which allows for public charging through a power metering and billing systems. Of the three methods, ground-level conductive rails are estimated to be the most cost-effective.[1]: 10–11
Government studies and trials have been conducted in several countries. Korea was the first to implement an induction-based public electric road with a commercial bus line in 2013 after testing an experimental shuttle service in 2009,[2]: 11–18 but it was shut down due to aging infrastructure amidst controversy over the continued public funding of the technology.[3] United Kingdom municipal projects in 2015[4] and 2021 found wireless electric roads financially unfeasible.[5] Sweden has been performing assessments of various electric road technologies since 2013 under the Swedish Transport Administration electric road program.[6]: 5 As of 2023 Sweden is pursuing cost-reduction measures for either wireless or rail electric roads.[7] France began testing rail and wireless electric roads in 2023. France[8] and Germany[9] reported in 2024 that overhead lines are too expensive, difficult to maintain, and pose a safety risk.
Terms like "electric highway" may also be used to describe regular roads fitted with charging stations at regular intervals.[10]
Technology
editTRL (formerly Transport Research Laboratory) lists three power delivery types for dynamic charging, or charging while the vehicle is in motion: overhead power lines, ground level power through rails, and induction through rails or resonant coils. TRL lists overhead power as the most technologically mature solution which provides the highest levels of power, but the technology is unsuitable for non-commercial vehicles. Ground-level power is suitable for all vehicles, with rail being a mature solution with high transfer of power and easily accessible and inspected elements. Inductive charging delivers the least power and requires more roadside equipment than the alternatives.[2]: Appendix D
Business model
editThe Swedish Transport Administration anticipates that a national electric road network would require interfaces between several players: the electricity supplier, the power grid company, the vehicle manufacturer, the road owner, the electric road technology operator, the metering and billing provider, and the user of the electric road. The ownership model can vary: the power grid company may own the secondary roadside electrical substations that power the electric road infrastructure or they may be owned by other players, and the power reading and payment system may be owned by a player separate from the infrastructure operator.[6]: 10–11
Early implementations
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Overhead power lines have been used for road transport since at least 1882 in Berlin with Werner von Siemens's trolley buses. Over 300 trolley bus systems were in operation in 2018. Power to trolley buses is normally delivered using a pair of trolley poles positioned on top of the vehicle which extends to the overhead power lines. Implementations for highway vehicles have been developed in the late 2000s and 2010s[11]: 15 but they are not suitable for non-commercial vehicles such as passenger cars.[2]: Appendix D
Ground-level power supply in the form of electrified rails is similar to overhead power lines in implementation. Instead of an arm or pole extending to overhead power lines, a mechanical arm extends from the bottom of the vehicle and aligns with a rail embedded in the road. The rail is then powered, and power is transferred through the arm to the vehicle.[11]: 16 Ground-level power supply is considered aesthetically preferable to overhead wires[11]: 20 and it is suited for all types of vehicles.[2]: 24
The concept of a wireless ground-level power supply for vehicles was first patented in 1894. A static-charging system for shuttle buses was demonstrated in New Zealand in 1996.[11]: 13 Similar systems have been implemented by Conductix-Wampfler and Bombardier PRIMOVE, which were later developed from static charging at bus stations to dynamic charging while driving.[2]: Appendix B
Development of electronic road systems has grown significantly from the late 1990s through the 2010s.[2]: 12–22 Several companies have developed and implemented electric road systems in the 2010s.[2]: Appendix B
Korea
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The Korea Advanced Institute of Science and Technology launched in 2009 a shuttle service with wireless dynamic charging through inductive coils embedded in the road. In 2013 OLEV launched a bus line in the city of Gumi.[2]: 16 Another bus line was launched in Sejong in 2015, and two more bus lines were added in Gumi in 2016.[12]: 4 All four wireless charging bus lines were shut down due to aging infrastructure. A new bus line was inaugurated in 2019 in Yuseong District.[13] Commercialization of the technology has not been successful, leading to controversy over the continued public funding of the technology in 2019.[3]
Sweden
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The Swedish Transport Administration, Trafikverket, established an electric road program that studied the feasibility of an electric road national infrastructure for Sweden. The fact-finding program began in 2012[14] and assessments of various electric road technologies in Sweden began in 2013.[15]: 12 Trafikverket expected the final report of the Swedish electrification commission by the end of 2022,[16] but it was delayed until December 2024.[17]
The final report by CollERS, the Swedish-German research collaboration on electric road systems, advised Trafikverket to select a single ERS technology, suitable for heavy trucks, with several suppliers who use an existing standard, coordinated with German and French ERS decisions, not necessarily led by the European Union but with their coordination, utilizing an ERS-technology-neutral payment system.[18]
Trafikverket was expected to announce its chosen technology for electric roads by late 2023,[19] but due to procurement offers for the first permanent electric road on the E20 highway exceeding the project's budget, in 2023 Trafikverket began investigating cost-reducing measures in order to realize the project within its budget.[7] The E20 project was funded at 500-600 million SEK, or about 24-29 million SEK per two lane-kilometers.[20]
France
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France plans to invest 30 to 40 billion euro by 2035 in an electric road system spanning 8,800 kilometers that recharges electric cars, buses and trucks while driving. Two projects for assessment of electric road technologies were announced in 2023. Three technologies are being considered: ground-level power supply, inductive charging, and overhead lines. Ground-level power supply technologies, provided by Alstom, Elonroad, and others, are considered the most likely candidate for electric roads. Inductive charging is not considered a mature technology as it delivers the least power, loses 20%-25% of the supplied power when installed on trucks, and its health effects have yet to be documented. Overhead lines is the most mature technology, but the catenaries and overhead wires pose safety and maintenance issues,[21] and motorway companies find overhead lines too expensive.[8]
Trials
editFrance constructed a test track for Qualcomm dynamic wireless charging of vehicles, and concluded testing in 2018.[22]: 9
Alstom has developed a ground-level power supply (alimentation par le sol - APS) system for use with buses and other vehicles.[23] The system has been tested for compatibility with snow plows and for safety under exposure to snow, ice, salting, and saturated brine.[24] Alstom will trial its electric road system (ERS) on the public road RN205[25] in the Rhône-Alpes region between 2024 and 2027.[26]
Vinci will test two electric road systems (ERS) from 2023 to 2027. Both technologies will initially be tested in laboratory conditions, and upon meeting the test requirements they will be installed along 2 kilometers each on the A10 autoroute south of Paris. Wireless ERS by Electreon will be tested for durability under highway traffic, and will attempt to reach 200kW of power delivery per truck using multiple receivers. Rail ERS by Elonroad, which supplies 350kW of power per receiver, will be tested for skid effects on motorcycles. Both systems will be interoperable with cars, buses, and trucks.[27]
Other countries
editJapan
editJapan tested an electric road system on a public road with Honda in 2018. [22]: 10
Germany
editBombardier conducted a dynamic wireless power transfer trial in Mannheim, Germany, in 2013.[22]: 9 Germany launched an overhead power line electric road in May 2019 on a 10 km (6.2 mi) section of Bundesautobahn 5 south of Frankfurt. The project is operated by the ELISA consortium which includes Siemens and Scania.[28] Results from the trial were mixed, finding high costs and difficult maintenance for the overhead lines, leading the Ministry of Transport to end its financial support of the trial.[9]
United Kingdom
editHighways England began a dynamic wireless power transfer project in 2015[29] but the project was cancelled in early 2016 for budgetary reasons.[4] Another dynamic wireless power transfer feasibility study, dubbed DynaCoV, began in 2021 and issued its final report in 2022. The study found that dynamic wireless charging is 10 times more expensive than conductive charging and is not financially feasible.[5] Proposed costs for 200 metres (220 yd) were were about 716,000 GBP for the inductive coils and their management units, £258,000 for civil costs including roadwork and electric grid connections, £64,000 for planning and commissioning, £18,000 for 12 months maintenance and data management, £129,500 for upfitting a bus and a van with wireless receivers, and £300,000 for the accompanying report on the project.[30] The company that participated in the study, Electreon, is set to pave its demonstration wireless charging road in 2024.[31]
United States
editIn May 2023, ENRX won a contract to build a one-mile wireless charging system capable of charging at up to 200 kW on State Road 516 near Orlando, Florida. The project is funded at 13 million dollars.[32] Detroit, Michigan opened in November 2023 a quarter-mile wireless charging road section near Michigan Central. The project was funded at 5.9 million dollars.[33] The infrastructure, provided by Electreon, powered a van driving at 9mph with 16kW of power.[34]
Indiana began constructing a strip of electrified highway in 2024 that uses inductive coil charging at 200kW, suitable for heavy trucks. The project costs 11 million dollars per quarter mile of road. Research on the project, conducted by Purdue University's Steve Pekarek, aims to show the technology could make a transition to heavy electric trucks more financially beneficial for businesses.[35]
References
edit- ^ Francisco J. Márquez-Fernández (May 20, 2019), Power conversion challenges with an all-electric land transport system (PDF), Swedish Electromobility Centre
- ^ a b c d e f g h D Bateman; et al. (October 8, 2018), Electric Road Systems: a solution for the future (PDF), TRL, archived from the original (PDF) on August 3, 2020, retrieved November 19, 2019
- ^ a b Kwak Yeon-soo (24 March 2019). "ICT minister nominee accused of wasting research money". The Korea Times.
- ^ a b Ed Targett (September 20, 2016), Who Killed the Electric Highway?
- ^ a b Steven Pinkerton-Clark (June 22, 2022), DynaCoV - Dynamic Charging of Vehicles - Project closedown report (PDF)
- ^ a b Björn Hasselgren (October 9, 2019), Swedish ERS - program background, current analysis phase and plans ahead (PDF), Swedish Transport Administration
- ^ a b "Vi avbryter upphandlingen för Sverige första permanenta elväg", Trafikverket, August 28, 2023
- ^ a b Marc Fressoz (May 9, 2024), "Les autoroutiers divisés sur les solutions à mettre en place pour faire rouler des camions électriques", L'USINENOUVELLE.com
- ^ a b Bilanz E-Highway: Lastwagen können Hälfte an CO2 sparen, DPA, March 1, 2024
- ^ "Western Australia building country's longest 'electric highway'". 19 August 2021.
- ^ a b c d Electric road systems: a solution for the future? (PDF), World Road Association, 2018, ISBN 978-2-84060-496-9
- ^ Smart Wireless Power Transfer Technology (PDF), Korea Advanced Institute of Science and Technology
- ^ 권명관 (July 22, 2021), "[모빌리티 인사이트] 도로 위만 달려도 전기차를 충전합니다, 일렉트리온", The Dong-a Ilbo
- ^ "Test och demonstration - resultat, erfarenheter, lärande och reflektioner", Region Gävleborg, March 24, 2023
- ^ Swedish Transport Administration (November 29, 2017), National roadmap for electric road systems (PDF), archived from the original (PDF) on November 24, 2020
- ^ Kenneth Natanaelsson (March 26, 2021), Elektrifiering av transportsystem (PDF), Trafikverket, archived from the original (PDF) on March 2, 2022
- ^ Energimyndigheten (Swedish Energy Agency) (January 2023), Delrapport inom uppdraget om handlingsprogram för laddinfrastruktur och tankinfrastruktur för vätgas, p. 20
- ^ Matts Andersson; et al. (January 31, 202), Choosing ERS technology for Europe (PDF), WSP Sverige AB, archived from the original (PDF) on March 10, 2024
- ^ Per Mattsson (January 18, 2023), "40 experter: Så blir det nya mobilitetsåret", Dagens industri
- ^ Johan Kristensson (September 5, 2023), "Skjuts upp – därför skenade kostnaden för Sveriges första permanenta elväg", NyTeknik
- ^ Laurent Miguet (April 28, 2022), "Sur les routes de la mobilité électrique", Le Moniteur
- ^ a b c Martin G. H. Gustavsson (April 2, 2019), Overview of ERS concepts and complementary technologies (PDF), Swedish-German research collaboration on Electric Road Systems
- ^ "Alstom transfers tram power supply technology to buses". Rail Insider. 26 September 2019. Archived from the original on 29 November 2020. Retrieved 29 November 2020.
- ^ Patrick Dupart (February 11, 2022), Compatibility of an in-road Electric Road System with winter service operations (PDF), Alstom, PIARC
- ^ "Les aides proposées par ATMB à ses clients légers et lourds pour la décarbonation des transports", ATMB, June 30, 2023
- ^ Jean-Philippe Pastre (June 30, 2023), "L'APS d'Alstom bientôt testé sur les routes", TRM24
- ^ Léna Corot (August 30, 2023), "Vinci teste la recharge par induction et par rail sur autoroute", L'USINENOUVELLE.com
- ^ Tim Wynne-Jones (October 2019), Third Rail (PDF), Institute of Road Transport Engineers
- ^ Feasibility study - powering electric vehicles on England's major roads, Highways England, August 2015
- ^ Elaine Meskhi (December 2021), DynaCoV - Final Feasibility Report on DWPT Deployment within the UK
- ^ Chris Randall (April 29, 2024), "Wireless charging project to take off in Coventry", elecdrive.com
- ^ "ENRX wins $13.3 million contract to supply in-motion EV charging technology on Florida highway". May 2023.
- ^ Breana Noble (November 29, 2023), "This road in Detroit is the first in the country to charge an EV, project leaders say", The Detroit News
- ^ Eric D. Lawrence (November 29, 2023), "Detroit touts first wireless-charging public road for electric vehicles in US", Detroit Free Press
- ^ Thorp, Ben (June 6, 2024). "Indiana is building an electrified highway to charge EVs as they drive over it". "All Things Considered". National Public Radio. Retrieved June 8, 2024.