Well to Wheels Analysis of Biofuels vs. Conventional Fossil Fuels : a Proposal for Greenhouse Gases and Energy Savings Accounting in the French Context

The recent development of biofuel production worldwide is closely linked to GHG savings objectives and to regional agricultural policies. Many existing studies intend to evaluate the net non renewable energy and GHG savings associated to the various biofuel production pathways. However, there is no consensus on the results of those studies. The main explanations of variations among the results are the following:

• energy consumption and GHG emissions of the reference fossil pathway,
• data used for the representation of farming processes and biofuel production processes,
• accounting for carbon storage in agricultural soils,
• reference use of the land,
• choice of an allocation method in case of coproduction.

There is a strong drive in the European Union for a certification on the sustainability of biofuel pathways. Germany, The Netherlands, The United Kingdom and France have started to work on reference framework for the evaluation of biofuel pathways, in particular (but not only) from the GHG emissions point of view. This study intends to detail a WTW assessment for first generation biofuels in the French context. A detailed description of today French agriculture and biofuel production is made in order to give reference data for the WTW analysis. Based on the existing biofuel pathways and their possible evolution, this study then evaluates the potential GHG savings according to the French objectives of biofuel use: 5.75% in 2008 and 7% in 2010.

The sensitivity of the results to regional factors (mainly in the farming processes) is then calculated in order to evaluate the possible variations. Effect of land use change is not taken into account in that study. The question of a national reference value is raised: in a certification process, is it possible to use one only reference value for GHG savings, or do we need more detailed references?