The range autonomy is one of the main barriers to the commercial success of the Electric Vehicles (EVs). However, statistics show that a large proportion of the daily trips are far below the maximum range announced by EVs constructors. Therefore, an EV with a reasonable sized battery and a Range Extender (RE) could satisfy a majority of needs achieving zero emissions in limited area and may fulfil an occasional over range trip. The main idea of this project is to study how Extended Range Electric Vehicles (EREV) could match the different usage patterns and what would be the acceptance and impacts of such a solution.
The goal of this project is to study the potential of an EREV in order to optimize the battery size, price and lifetime in addition to giving more performance and reliability to the vehicle.
The range extender is an on-board electricity generator powered by a non-electric actuator. Classically in security applications for instance, an Internal Combustion Engine (ICE) is associated with an alternator. In this work such a device for a range of power smaller than usual has been studied and sized.
Moreover, special attention has been drawn to possibilities offered by a Fuel Cell system and used as Range Extender (RE). A battery associated with a RE could be an optimal solution for a custom-made EV. But the main issue is to define realistic specifications that come from accurate statistics about different kind of location and use at the European level.
For this purpose, the project is based on an in-depth analysis of users' profiles and expectations conducted on data bases from different European countries. This typology of usage patterns will be associated to optimal sizing of technological solutions.
The EVREST Project has been composed of three main parts:
Specifications part: WP1 provided in puts and the needed data for different work packages.
Solutions part: from the user category and needs, scenarios of electric mobility have been defined in WP2 and WP3.
Evaluation part: the assessment of the established scenarios has been split into two steps.
The 1st step studied the impact evaluation of the different solutions on different aspects and included:
WP 4 aimed at exploring the perspectives of different specifications of EVs/range- extended EVs for the electric power demand and provision of energy in temporal and spatial terms as well as the impacts on transport caused emissions and their (local) impact.
WP5: from the different specifications of EREVs concepts developed in WP2, WP5 will analyse the environmental impacts for the production and use phase according to the method of Life Cycle Assessment (LCA).
The 2nd step consisted in collecting conclusions from different WPs in order to carry out a Sustainable Development Analysis and in providing recommendations at different levels. This will be the aim of the WP7.
To ensure the smooth running of the EVREST project, WP8 is dedicated both to the management and the dissemination of the project.
Some of the most relevant findings are listed below (more comprehensive information is available at the project website):
- An improved knowledge on car usage characteristics on a longitudinal perspective (i.e. the car mileage of every day of a full year) is a prerequisite for the multi-criteria optimization of vehicle concepts not only with regard to electro-mobility.
- The analysis of car-usage behaviours of conventional ICE-vehicles for the period of one year shows a high variation in the intensity of car use between the regularly low mileages for the frequent daily mobility against rare events such as excursions or holiday trips with a high mileage.
- As the raw material and energy demand for batteries and the resulting environmental impacts are not negligible, EREVs allow for an optimization and downsizing of the battery according to the use profiles and here for the basic daily mobility requirements. EREV batteries should be designed according to typical mobility ranges of everyday travel.
- Compared with a conventional ICEV the environmental impacts of EREVs during the use phase compensate the higher impacts during vehicle production
- REVs allow for an avoidance of emissions similar to BEVs in urban settings where those emissions must be regarded as more critical.