LCA s of biogas production in Central Germany A regionalized perspective

Transcription

1 LCA s of biogas production in Central Germany A regionalized perspective Workshop: Biomass for energy - lessons from the Bioenergy Boom Steffen Schock, Alberto Bezama, Daniela Thrän November 2014 KUBUS, Leipzig, Germany

2 Overview Introduction Concept & case study: A regional life cycle approach in Central Germany Results Outlook & conclusion 2

3 Introduction: Biogas development in central Germany 300 Number of Plants Significant biogas plant infrastructure 0 Sachsen Sachsen-Anhalt Thüringen Electricity generation from Biogas Mio. kwh Saxony Saxony-Anhalt Thuringia Share of Biogas-electricity from gross electricity production % Data Source: DBFZ, ZSW Saxony Saxony-Anhalt Thuringia

4 Introduction: LCA s for biogas production Many LCA studies in the recent years on biogas production Large variation of results Hard to simplify Different reasons for the variations: Methodological differences - Functional Unit - System Boundaries - Methodological Assumptions Complexity of natural systems 4

5 Problem related to agricultural biogas production What to do if we want to Analyze displacement effects on a system level Identify optimization potentials on a regional/larger level Comparisons of the environmental performance and identification of improvement potentials between regions 5 Source: O keeffe

6 Assessing agricultural biogas systems struggling with the heterogeneity/complexity of natural systems Dependence of the output complex in relation to the input Variability of input data System boundary not clear defined Source: Wikipedia-CC-BY-SA-3.0-de Diffuse nature of agricultural biogas production Combination of different technical options 6

7 Environmental assessment: Problem of scales Degree of simplification high Area of impact Health Environment Ressources Scale global Spatial, temporal, specificity Climate change Substances input regional low Biodiversity local Source: Witing, Schock 7

8 Environmental assessment: Problem of scales Spatial, temporal, specificity Degree of simplification high Area of impact Health Environment Ressources Complex, multi-causal relations Climate change High uncertainties Scale Dealing with it by using modeling approaches: global Our solution: integrated statistical modeling approach using commonly available data regional Substances Still inherent uncertainties input but consistent on a regional scale low Biodiversity local Source: Witing, Schock 8

9 Case study Central Germany : Spatial delimitation Agro-climatic Regions (Roßberg et al.) Homogeneous agricultural production regions 9 Picture source: Flickr / mgrenner

10 System description Two staged inventory process For each subsystem development of a parameterizable, generic production module Agricultural Field Substrate Transport Silo Slurry storage Electricity Machinery Agro Chemistry Seeds Agricultural System Fertilizer management Digester Secondary fermenter Digestate Storage CHP Heat Conversion System System Boundary 10 Picture source: flickr / tuxdriver

11 The concept: Agricultural production Regional Statistics Geo-Data Farm typology LCI - Datasets Farm management Cropping systems Nutrient balances 11

12 Case study: Agricultural inventory Differentiation of cultivation systems / crop-management systems Management areas/ regional differentiation Agricultural operating systems crop farm livestock farm mixed farm Tillage systems conventional conservation tillage Crops Winter wheat corn silage rapeseed Crop management Fertilizer applications Plant, Harvest & Tillage operations Management Timing Selection of crop rotations Management database User specified complexity Pool of crop rotations (regionally differentiated & actually practiced) LCI Input Source: Witing et al 12

13 System description Agricultural Field Substrate Transport Silo Slurry storage Electricity Machinery Agro Chemistry Seeds Agricultural System Fertilizer management Digester Secondary fermenter Digestate Storage CHP Heat Conversion System System Boundary 13 Picture source: flickr / tuxdriver

14 Case study: Biogas in Central Germany Data source: DBFZ 14

15 Case study: Plant inventory Technical Data: DBFZ Biogas-Database (Germanwide survey) Efficiencies Heat usage Operating hours Data gaps: Literature / Expert opinion Source: Martina Nolte / CC-BY-SA-3.0-de 15

16 Some preliminary results of biogas production (GHG) GHG Emissions (kg CO2-eq / kwh el) BG 1 CumBG 1 BG 2 CumBG 2 Credit Power Credit fertilizer Credit Heat Plant operation Methane Emissions construction Substrate Sample plants: BG 1 Saxony ~500 kw Silage/ Cattle Slurry BG2 Thuringia ~250 kw Pig slurry /silage

17 Discussion & conclusion (1) Biogas is contributing to GHG emission reduction, amount varies Regional variability can be captured by applying the developed approach For the full picture - full LCA (inclusion of other local Impact categories) Level of regionalization strongly dependent on the scope 17

18 Discussion & Conclusion (2) The development of regionalized impact categories can add substantially to the accuracy of the results (especially in combination with GIS) In the context of bio-economy regionalization is important for the sourcing of agricultural substrates 18

19 Thank you! Helmholtzzentrum für Umweltforschung GmbH Deutsches BiomasseForschungsZentrum ggmbh Leipzig Germany 19 Steffen Schock