Federal Department of Economic Affairs DEA Agroscope Reckenholz-Tänikon Research Station ART LCA of energy crops from the perspective of a multifunctional agriculture R. Freiermuth Knuchel, T. Kägi, G. Gaillard, Agroscope ART Th. Hölscher, K. Müller-Sämann, Agentur ANNA S. Deimling, PE International Life Cycle Management Conference 2007 28/08/2007
Background & Aim of the Project Partners: Agentur ANNA (D), PE International GmbH (D) and Agroscope Reckenholz-Tänikon ART (CH) Funding: Innovation fund of badenova AG & Co. KG Aim: Energy and water supplier in Southern Germany Supports regional research projects for a sustainable water and energy use Elaboration of a funded decision basis for the choice of ecologically and economically favourable bioenergy carriers Evaluation of the impact on the environment when substituting food with energy crops. Focus on nitrate leaching Site specific (German upper Rhine Valley) 2/12
Materials & Methods: System boundary Resources SALCA GaBi 4 Infrastructure: Buildings Machinery Means of prod.: Seeds Mineral fertiliser Pesticides Energy carriers Ashes Cultivation: Green manure Soil working Manure Seed Plant protection Mechanical weed control Harvest Transport to farm gate Miscanthus Willow Maize silage Triticale Meadow Transport and processing Fermented substrate Combustion Biogas Heat Electricity 3/12
Materials & Methods: System description REFERENCE CROP ROTATION winter wheat turnip rape grain maize grain maize summer barley winter rape spontaneous greening triticale turnip rape silage maize mustard silage maize mustard summer barley winter rape BIOENERGY SCENARIOS spontaneous greening permanent meadow willow short rotation coppice miscanthus Reference crop rotation over 5 years Energy crop rotation over 5 years Permanent meadow, willow and miscanthus: 20 cultivation years Results for permanent cultures expressed for 5 years Utilisation paths Combustion Biogas plant Food and Feedstuff Green manure 4/12
Materials & Methods: LCA Life cycle inventory Site specific management data Inventory: ecoinvent-database Version 1.2 (Frischknecht et al. 2004), SALCA-database (Nemecek et al. 2004; Nemecek & Erzinger 2005) and GaBi-database (PE International) Impact categories (Midpoint) Global warming potential (IPCC) Terrestrial ecotoxicity (EDIP97) Ozone formation (EDIP97) Aquatic ectotoxicity (EDIP97) Acidification (EDIP97) Human toxicity (CML 01) Eutrophication (EDIP97) Non renewable energy demand (ecoinvent) Renewable energy demand (CML 01) Calculation: Agriculture: SALCA (Swiss Agricultural Life Cycle Assessment), based on software TEAM Energetic conversion: GaBi 4 (Product Sustainability software) 5/12
Results 1: Agricultural cultivation Functional Unit: kg odm*5yr. CR Miscanthus Willow reference CR energy Meadow Impact category unit absolute % of Reference non ren. energy demand MJ-eq. 3.188 60 36 21 16 Global warming pot. (100 y.) kg CO2-eq. 0.556 53 28 16 11 Ozone formation kg Ethylene-eq. 0.000 70 45 23 22 Acidification kg SO2-eq. 0.003 261 435 20 12 Eutrophication kg N-eq. 0.011 89 62 19 18 Terrestrial ecotoxicity Tox. points 0.056 44 7 21 16 Aquatic ecotoxicity Tox. points 0.425 54 11 4 4 Human toxicity Tox. points 0.009 57 39 21 18 Direct nitrate leaching kg N 0.007 69 0 18 16 Yield kg odm/ha 32542 178 116 232 164 Legend: similar better much better worse Lowest impact for miscanthus and willow, comparable for CR energy thanks to high yield CR energy and meadow: High impact for acidification due to ammonia emissions from fermented substrate For functional unit ha: CR energy higher nitrate leaching and higher impact for ozone formation, acidification and eutrophication than CR reference 6/12
Results 2: Agric. cultivation / Economy /ha 500 400 300 200 100 0 CR reference Gross Margin CR energy Meadow Willow Miscanthus Comparison of full costs shows: Miscanthus is the cheapest biomass Willow needs to be dried which leads to higher costs Permanent meadow has a very low productivity and therefore the highest full costs. 7/12
Results 3: Energetic conversion MJ/kg odm 20 15 10 5 0-5 -10-15 -20-25 -30 CR Energy Biogas Energy fixation / Energy use Meadow Biogas Miscanthus Combustion Willow Combustion Non renewable Energy saved Renewable Energy used/fixed Delta All options show a saving potential, which is highest for miscanthus followed by meadow, CR energy and willow The saving potential is e.g. due to substitution of fertilisers with fermented substrate and the combination of electricity/heat production 8/12
Results 4: Global warming potential CML2001, Global warming potential (100 years) 2,0 Agric. prod. [kg CO2-equiv. /kg odm] 1,0 0,0-1,0-2,0-3,0 CR energy (Biogas) Meadow (Biogas) Miscanthus (Combustion) Willow (Combustion) BM-CO2 (B) Silage prod. Transports Th. energy (B) Pow er (B) Conversion plant Fertilizer (B) Infrastructure -4,0 Absolute CO 2 reduction potential ranges from -1.27 to -1.63 kg CO 2 /kg odm Dominant are emissions from conversion plant and the benefit (B) for substituting fossil energy carriers Transportation, silage production and infrastructure play a minor role for global warming potential 9/12
Results 5: Eutrophication EDIP 1997, Eutrophication 0,010 Agric. prod. [kg N-equiv. / kg odm] 0,008 0,006 0,004 0,002 0,000-0,002 CR energy (Biogas) Meadow (Biogas) Miscanthus (Combustion) Willow (Combustion) Silage prod. Transports Th. energy (B) Pow er (B) Conversion plant Fertilizer (B) Infrastructure Eutrophication and acidification: the agricultural production plays a dominant role 10/12
Conclusions Double conflict: Production of bioenergy vs. Nitrate leaching Current practice vs. Nitrate leaching LCA results depend on the functional unit chosen showing the conflict of interests between the functions of agriculture (land use, productive and financial function). Miscanthus and willow allow a resource and groundwater protecting production of bioenergy. Permanent meadow has the same effect but the yield is lower. Looking at the whole system, Miscanthus allows the biggest reduction of CO 2 -emissions compared to the use of fossil energy carriers and is from the economic point of view most favourable. 11/12
Thanks To Thomas Hölscher (Agentur ANNA) for leading the project To the partners Sabine Deimling (PE International GmbH), Karl Müller-Sämann (Agentur ANNA), Thomas Kägi, Gérard Gaillard and Thomas Nemecek (ART) To badenova AG & Co. KG for funding the project and for your attention! 12/12