Life cycle GHG emissions of biofuels: Results from review of studies Emanuela Menichetti UNEP-DTIE, Energy Branch European Environment Agency Expert workshop Copenhagen, 10 June 2008

Bioenergy Strategy developed in 2007 UN Energy report on Bioenergy Most relevant current activities GBEP => UNEP entrusted with developing sustainability work stream RSB => UNEP is a Steering Board Member and participates in all 4 technical working groups Jatropha Roundtable => network of centres of excellence to share information on agronomics, sustainability criteria, technologies and business models UNEP’s Activities on Bioenergy

Two main review studies Chapter on LCA for the OECD MCM report in cooperation with the IEA Report for the International Panel for Sustainable Resource Management Life cycle GHG emissions of biofuels

Overview Review and analysis of 60 studies Full LCA studies: 32% Energy and GHG emission balances: 33% Methodological / review studies: 23% Life cycle inventories: 7% Energy balances: 5% Focus mostly on transport applications

Selected results for GHG (w/o LUC)

Key determinants of results (w/o LUC) Two main life cycle stages – and within these two – a limited number of variables are responsible for the largest impact share Agricultural phase N 2 O balance Assumptions on co-products (and allocation) Transformation phase Process energy Assumptions on co-products (and allocation)

Example: rapeseed biodiesel Agricultural phaseConversion phase Land use reference scenario Crop yieldAmount of fertilizers N balanceAllocationEnergy fuel used Co-products allocation Green: quite consistent background assumptions Orange: some discrepancies observed, it affects results to some extent Red: high inconsistency area, it affects results significantly N 2 O emissions Ecobilan (2002) EMPA (2007) IPCC default value Emission factor (N 2 O) 0.5% %1% Ecobilan (2002) EMPA (2007) Mass allocation (46% to RME) Economic allocation (87% to RME) Overall GHG improvement on biodiesel : Ecobilan 80% vs. EMPA 23%-41%

Allocation methods QUESTIONS: What is the most appropriate allocation method for biofuel co-products for regulation purposes? One method for whole life cycle or mixed approach? Consistency with allocation method(s) in fossil fuel chains? Sub- division System expansion Allocation based on physical criteria Allocation based on other criteria Mixed methods No allocation to co- products Not applicable / Not available Mass- based allocation Energy content- based allocation Economic allocation

Influence of process energy QUESTION: What should be used for regulation purposes? Present average mix, state-of-the art, BAT, expected trends? Quantity and type of energy source significantly affect LCA results State-of-the art vs. old plants (e.g. Wang et al. 2007) Wide range of specific process energy consumption observed in reviewed studies (e.g. Unnasch and Pont, 2007)

Other methodological aspects Various (and non harmonised) LCI databases Various LCIA methods used Most studies only cover CO 2, N 2 O and CH 4 Various reference scenarios modelled Uncertainty related to the fossil fuel chain: Variability in assumptions and results of fossil fuel chains Lack of updated LCA of marginal fossil fuel production (deep extraction, unconventional oils) Comparison with average or marginal fossil fuels?

Land use change Very significant impacts on overall GHG balances Direct land use change can be integrated in LCA Harmonization on data and methods needed More research needed to include indirect land use change What is the reference baseline? How to take productivity and process improvements into account? tC/ha Arable land Cultivated land Permanent grassland GrasslandLightly forested area Tropical rain forest (min. soil) SavannahOil palm plantation EC RES directive German SBO draft

Conclusions Research gaps Need for more full LCA studies on other crops and geographical contexts Number of open questions N 2 O emission factors Allocation methods Consistency of fossil fuel chain LCA Level of technology representativeness for policy-making decisions Direct and indirect land use change Parametric LCA? To better evaluate the influence of assumptions To depict future improvements To orientate policy making Harmonisation of rules GBEP, RSB, UNEP LCI, EPLCA Look at experience in the eco-labelling sector (PCR-like process)

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