The data analyzed by Aston University combines and compares the behavior patterns of 25 Mitsubishi i-MiEV drivers over two consecutive quarters. The results form part of the CABLED project, which will see an overall total of 110 ultra low carbon vehicles from different manufacturers, tested on the roads of Birmingham and Coventry as part of a £7.5-million (US$11.9-million) year-long Government scheme.

Each vehicle in the CABLED trial is fitted with GPS and data logger, designed and installed by Coventry based RDM Automotive. These record the usage, location and charging habits of each vehicle. From this data the following information can be analysed:

• Frequency of individual journeys
• Length and duration of journeys
• Date and time of journeys
• Energy used per journey
• Duration and amount of energy transferred during charge
• External temperature
• Location of charging/parking, i.e. home, work, public etc.
• Average speed

This data will also be used to map out a future network of electric charging points, to further extend range and improve the convenience of electric vehicles.

The CABLED results at this stage show that:

• A Mitsubishi i-MiEV can travel around 80 miles when fully charged and on average, drivers are using less than 30% of their total vehicle charge in a typical daily use.
• The average charge time per i-MiEV vehicle is two hours. This provides sufficient charge for between 20-40 miles of travel at a cost of between 40p to £1, depending on the tariff.
• Drivers habitually charge their vehicles, whether the battery is half full or nearly empty, in much the same way as a laptop or mobile phone, which will influence the next generation of battery technology that is incorporated into these vehicles.
• The most popular time to charge vehicles is overnight but as around eight in 10 journeys use less than 18% of the battery and five average length journeys could be completed on one charge, there is now evidence to support the need for intelligent technology that will allow electric vehicles to interact with the national grid.

Collecting real-world analysis of electric vehicles is essential in understanding actual demands and requirements of low carbon vehicles for consumers. The journey data gathered is already showing that the current generation of vehicles are cheap to run as well as being comparable to petrol and diesel vehicles for speed, ease of use and daily journey distance.

—Brian Price, lecturer in Engineering Systems and Management at Aston

Project Leader from CABLED co-ordinating partner Arup believes the data presents a positive outlook for the mass take-up of electric vehicles.

The phenomenon known as ‘range anxiety’—concern about battery life when undertaking long journeys—is falling as drivers become more familiar with their vehicles. The low cost of ‘refuelling’ in relatively short periods of time reinforce this. While there are technical challenges ahead—such as extending vehicle range and making provision for an increased demand on the national grid—our results show that even current EVs are more than capable of meeting users’ day-to-day needs.

—Neil Butcher

The West Midlands CABLED consortium comprises 13 organizations, led by Arup. Part funding for the project came from the regional development agency, Advantage West Midlands.

Each of the six vehicle manufacturers—Jaguar/Land Rover, Mitsubishi/Colt, Mercedes Benz/smart, Tata Motors, LTI and Microcab Industries—are contributing their own vehicles towards the low carbon scheme, which includes a mix of fully electric vehicles, plug-in hybrids and hydrogen fuel cell cars.

Electricity providers E.ON are delivering charging points for the trial with assistance from the city councils of Birmingham and Coventry. In total, over 340 cars being trialed in several regions across the UK.