The importance of quantifying energy savings and improvement in energy efficiency for each
sector of the economy is now widely recognized in order to demonstrate progress towards
targets and compliance with legal obligations. The focus of this paper is specifically on
evaluating energy efficiency in transport using the ODEX methodology.
More detailed data has recently become available on transport energy trends and the
underlying factors that allow the authors improve the calculation of Ireland’s transport
ODEX. Through data mining of administrative databases mileage, volume, age, engine type
and size data are available at a disaggregated level for each mode of road transport.
In particular this paper examines private car energy efficiency, quantifying the change arising
from improved data. There was an overall slight improvement (0.71 percentage points) in the
Irish private car ODEX when both proposed changes of using MJ/km as the unit consumption
measure and modeling the stock by vintage were applied.
The overall effect of the revised transport ODEX calculation does not show a significant
increase in energy savings associated with the value of the ODEX indicator (0.82%).
However the purpose was to improve the methodology of how the ODEX was being
calculated, not necessarily increasing the savings
