french institute of science and technology for transport ... - Ifsttar

Research orientation 1_Mobility, the environment and energy
How households are adapting
to rising fuel prices
The considerable rises in fuel prices since the beginning
of the years 2000 have prompted more in-depth analysis
of the (variable) impacts this has had on household car
ownership and use.
A CERTU study on travel in the period 2000-2010 summarizes
the research started at INRETS in 2009 and completed
in 2011 into the way households adapted to fuel price rises
during the period 1999-2008. The research team has also
investigated the specific impact of price volatility.
What has emerged is that these price rises have led to a substantial
reduction in the distances travelled by car. As a consequence,
although the number of cars continues to increase,
overall traffic levels in France have remained constant since
2005. Another long-term effect is that vehicle manufacturers
and consumers are tending to favour more economical models,
particularly diesel. The price sensitivity of households to fuel
prices is greater when the rise lasts for some time (after 2004)
and when prices are volatile (the large increase in mid-2008
which was followed by a collapse).
Apart from this overall impact, when households are monitored
over a several years, certain vulnerable groups stand out: the
poorest individuals and those who live in the least dense zones
cannot reduce their mileages because they have no alternative.
A sudden price rise like the one in 2008 (when almost half of all
motorists reported driving less) amplifies these impacts: some
individuals, who were thought to be incapable of reducing
their mileages, still manage to restrict their car use even more
drastically. But how? Gaining a clearer picture of these groups
and how their behaviours change would allow us to design
compensatory social measures (fuel cheques, re-evaluation
of the per-kilometre tax deduction, etc.) that target them. All
topics that are worth studying…
160
150
140
Fuel prices between 01/1999 and 12/2011
(“DIREM” series, constant Euro – end 2011 – per hectolitre)
130
120
110
100
90
80
70
Gazole
Super SP95
60
01/01/99 31/12/00 31/12/02 30/12/04 30/12/06 29/12/08 29/12/10
43
@ CONTACT
laurent.hivert@ifsttar.fr
Storing energy in hybrid vehicles
Accelerated ageing
IFSTTAR played an active role in the Simstock project
which was completed in 2011 and financed by ADEME
to the tune of €2M. For three years, the 15 project partners
from industry and academia mounted a large-scale
experimental operation and developed joint protocols
and a common methodology to investigate the ageing
of the batteries and supercondensers used in hybrid
vehicles.
A great deal is at stake here, as if these vehicles are to
become acceptable and widely used we must improve forecasting
of the performance and lifetime of the on-board energy
storage systems used in these complex technologies.
Accelerated ageing tests were conducted for us to develop ageing
models and build up a large database on the ageing of the
batteries and supercondensers under experimental conditions
which although simplified are nevertheless representative of
use in a hybrid vehicle. The influence of utilization parameters
(temperature, current amplitude, exchanged
charge and variations in state of charge) has
been demonstrated and led to the development
of ageing models which have the potential to
be implemented in energy simulation tools for
vehicles.
The project partners are planning to continue
their research by extending it to cover real loading
conditions (real current profiles, rest periods and
temperature variations). Studies of battery ageing are
faced by the rapid development of technologies which are
not yet industrially mature and the complexity of the mechanisms
that are at work during real use. In addition, it is not possible
to extrapolate directly to the conditions of “electric vehicle”
or “hybrid vehicle” use. Plenty of work remains to be done!
@ CONTACT
gerard.coquery@ifsttar.fr & serge.pelissier@ifsttar.fr
Battery cell
for vehicle
applications.
ANNUAL REPORT 2011 ifsttar.fr