Associate Professor, Aalborg University

Electric Roads

Electric Roads

on Jul 27, 2016

To date, I have published two reports about electric reports:



Version 1 from 2012 was published before any major developments in conductive electric roads, so the cost and performance of electric roads are based on technologies which have similar characteristics such as electric trams and transmission lines. In version 2, a more in depth analysis was carried out since new data became available about electric roads. A brief overview of the concept is provided in the video below, followed by a summary of version 2 and the key messages from the study.


Affordability of Electric Roads (4 mins)


Brief Overview of the Concept and Study (14 mins)


Summary: Version 2, eRoads

This study compares electric roads with oil (petrol and diesel) and battery electric vehicles, using Denmark as a case study. Electric roads can reduce the cost of electric vehicles by supplying them with electricity directly from the road rather than via a battery for long-distance journeys. In this paper, an electric road scenario is compared to both an oil and battery electric vehicle scenario using the 2010 Danish energy system, but for two sets of costs: one set based on historical costs from the year 2010 and one based on projected costs for the year 2050.

The results indicate that electric roads are more expensive than oil today, but they will be cheaper than oil in 2050. Furthermore, electric roads are cheaper than Battery Electric Vehicles in all of the scenarios considered here, which indicates that the upfront investment required to build the electric roads is less than the additional battery capacity required for electric vehicles if they are not installed.

The electric road and battery electric vehicle scenarios are more efficient and produce less carbon dioxide emissions than their corresponding oil scenarios for two key reasons: 1) the vehicles are more efficient and 2) electric vehicles enable more renewable electricity to be integrated onto the electricity grid. This is particularly evident in 2050, since the price of fossil fuels increases while the price of renewable electricity and batteries decreases. Finally, the electric road scenarios can facilitate more reductions in the energy demand and carbon dioxide emissions, since they also enable heavy-duty transport to be electrified such as trucks and buses. It is unlikely that these forms of transport will be electrified without electric roads, due to the relatively high cost of on-board battery storage.


Key Messages: Version 2, eRoads

All Figures and Tables referred to here are in the full report.

Transport is the Largest Part of the Energy System

  • Transport demand is increasing: it increased by almost 50% from 1980-2010 in Denmark.
  • The renewable energy penetrations achieved to date in transport are relatively low: Denmark has a renewable energy share of over 50% in electricity and heating, but only 5% in transport.
  • Vehicles are the most expensive component in the energy system: in 2010, vehicles account for ~45% of the annual energy system costs in Denmark which equates to ~€10 billion/year (see Figure 3).
  • Transport is the most expensive sector in the energy system: in 2010, the transport sector, which includes vehicles, fuels, and other costs, accounted for two-thirds of the annual energy system costs in Denmark (see Figure 3), with electricity and heating making up the remainder.

Electric Cars are Much Cheaper with Smaller Batteries

  • Batteries are the most expensive part of an electric car and account for more of the annual costs than all of the other major costs combined (see Figure 2).
  • If battery costs are excluded, then electric cars are already be cheaper than conventional diesel and petrol cars (see Figure 2).

Electric Roads are Relatively Cheap Compared to Other Transport Costs

  • Electric roads (eRoads) supply electricity to the vehicle while it is moving, like an electric train or trolley bus.
  • The hypothesis in this report is that eRoads should be installed on the major routes on the road network between densely populated areas, so electric vehicles can use electricity from the road instead of relying on an on-board battery. By doing so, the battery capacity required in the electric vehicle can be significantly reduced.
  • Many different proposal are currently in the research, development, and demonstration phases: 17 were identified in this study (see Table 1 and Table 2).
  • Two primary methods of charging are being developed for electric roads: conductive and inductive.
  • Elonroad ( is used as a benchmark in this study for the cost and performance of an electric road: in most cases, conservative assumptions are used here since Elonroad is currently in the research and development phase, with the first demonstration due to begin in early 2017 (see Table 5). For example, it is assumed that Elonroad will have an investment cost of €1.5 million/km-one-way, which is double their current forecasts, and a lifetime of 10 years is applied, even though many of the components will last much longer.
  • An electric road network is presented for Denmark in this study (see Table 4 and Figure 7) which assumes that everyone in Denmark will be within 50 km of an eRoad route. To do so, eRoads are installed on two lanes over 1350 km of roadway, so in total 2700 km of eRoads are installed.
  • The total annual cost of installing and maintaining 2700 km of eRoad infrastructure in Denmark is ~€500 million/year (see Figure 8). In comparison, the total annual cost of vehicles in Denmark is ~€10 billion/year (see Figure 3), so the eRoad infrastructure represents a relatively small cost in the transport sector.

This Study Compares Electric Roads with Oil and Battery Electric Vehicles

  • The 2010 Danish energy system is used here to compare oil, eRoad, and battery electric vehicles.
  • Costs from two different years are applied to the 2010 Danish energy system: historical costs based on the year 2010 and forecasted costs for the year 2050, primarily since some of the key costs in the energy system are likely to change significantly between 2010 and 2050 such as fuel, CO2, battery, and renewable energy costs.
  • Cars, trucks, and buses are all electrified in some of the eRoad scenarios, but only cars are electrified in the battery electric vehicle scenarios, since the cost of on-board batteries is extremely high to achieve sufficient range in trucks and buses.
  • Electric vehicles in the eRoad scenarios have a range of 150 km, while battery electric vehicles have a range of 300 km or more.

eRoads are Cheaper than Batteries in All Scenarios & than Oil in the Future

  • eRoads cost more than oil today based on 2010 costs (see Figure 9), but due to 1) increasing fuel and CO2 costs combined with 2) reducing battery and renewable energy costs, eRoads are cheaper than oil based on the 2050 costs (see Figure 12).
  • eRoads are cheaper than battery electric vehicles in every scenario considered here (see Figure 9 and Figure 12): the additional upfront investment required to construct eRoads is cheaper than the additional cost of extra storage capacity in the vehicle, even after assuming significant reductions in battery costs in the future (see Figure 12).
  • eRoads and battery electric vehicles are more efficient and less polluting than oil transport, primarily because the vehicles themselves are more efficient, but also because their batteries can facilitate more renewable electricity such as wind power (see Figure 10 and Figure 13).
  • eRoads can reduce the energy demand and carbon dioxide emissions more than battery electric vehicles, since they can facilitate the electrification of heavy-duty transport such as trucks and buses (see Figure 10 and Figure 13).

Recommendations: eRoads are One of the Most Promising Alternatives to Oil

  • Policymakers should allocate more funding to analyse, develop, and demonstrate electric roads, since the results here indicate that they are a very promising technology for the cost-effective decarbonisation of road transport.
  • Industry should release key cost and performance data (see Table 5) based on the upcoming demonstrations of various electric road technologies, to validate the conclusion that eRoads are a low-carbon and cost-effective alternative for road transport in the future.
  • Key stakeholders in the electricity, vehicle, road, and construction sectors will need to combine their skills and backgrounds to enable the implementation of electric roads. Ultimately, this could lead to a new institution, like a conventional Transmission System Operator in the electricity sector, that is solely responsible for the implementation, operation, and maintenance of the eRoad infrastructure.