Bio-energy greenhouse gas life cycle assessment review

Transcription

1 Bio-energy greenhouse gas life cycle assessment review CO 2 Summit: Technology and Opportunity Helena Chum Ethan Warner Garvin Heath Maggie Mann June 8 th, 2010 NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, operated by the Alliance for Sustainable Energy, LLC.

2 Overview Background Bioenergy systems Bioenergy sustainability Life cycle Assessment (LCA) LCA literature review Attributional literature Land use change methodologies Future potential for bioenergy Land Use Management 2

3 Bioenergy is a Part of a Complex System Dornburg et al

4 Human Dimension Local, Regional,Global Potential Impacts: - Abiotic Depletion - Potential Acidification - Eutrophication - Global Warming Potential - Ozone Layer Depletion - Human Toxicity - Marine Toxicity - Ionizing Radiation - Land competition -Photochemical Oxidation - Biodiversity Feed Production & Supply Logistics 4 Infrastructure

5 Attributional Life Cycle 5

6 Literature collection criteria Focus on GHGs 1. Must be a life cycle assessment reporting at least CO2. 2. Must be only attributional or report it separately. 3. Must exclude direct land use or report it separately. 4. Required functional unit: weight CO2-eq/distance traveled or /energy. Alternatively, annual or lifetime emissions reported with data to calculate above functional units. 5. Must be in English. 6. Must be an original analysis/estimates. 6

7 Literature Collected to Date Fuels Ethanol: 50+ references Biodiesel: 30+ references FT-Diesel: 10+ references Green Diesel: 5+ references DME: 5+ references Methanol: 5+ references Other Misc. Fuels: 10+ Biopower: 40+ references Includes biomass co-firing, combustion, pyrolysis, and gasification; land fill gas, anaerobic digestion, and the use of municipal solid waste Only some of these categories are included in this presentation 7

8 Data Categorization Hierarchy Divisions Fuel Type/Technology Categories E.g. Ethanol, biodiesel, methanol, FT-diesel, electricity-co-firing, electricity-gasification, etc. Feedstock category E.g. Starch crops, sugar crops, plant oils, herbaceous/srwc, etc. Primary energy source Location (generally based on where the feedstock is grown) Co-product credit calculation method Coal, natural gas, grid average, cogen systems North America, European Union, Asia, Oceania, Africa, South and Central America System Expansion, allocation by economics, energy, mass, product process 8

9 Definition of Allocation Energy use and emission burdens of a given biofuel pathway are distributed among all products according to their mass output shares Energy use and emission burdens of a given fuel production pathway are distributed among products according to their energy output shares Distributes energy and emission burdens based on economic revenue shares of individual products Energy use and emissions burdens of producing the product displaced by the co-product are estimated. The estimated energy use and emissions burdens are credits that are subtracted from the total energy use and emission burdens of the biofuel production cycle 9 ISO

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16 Limitations of Literature and Future Progress Limitations: Shortage of estimates on existing alternative technologies (e.g. land fill gas) Coverage outside North America and the European Union is generally lacking. Summary: A fair amount of depth for a limited set of biodiesel, ethanol, and power focused pathways for certain countries. Not a lot of breadth. Future progress: Continue literature collection Focus on additional alternative fuels Apply quality screens Exploration of other impacts and/or functional units E.g. water use, criteria pollutants, dluc E.g. weight CO2-eq/weight biomass or /hectare 16

17 Consequential Life Cycle Assessment and Land Use Change

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19 U.S. Environmental Protection Agency (EPA) 2010 analysis of Renewable Fuel Standard 2 (RFS2) Models: DAYCENT/CENTURY, FAPRI-CARD 2010, FASOM, GREET 1.8c, MODIS v5, and MOVES 2010 (Partial Equilibrium) Scenario: Business as usual for 2022 compared to 2022 with the Energy Independence and Security Act (EISA) mandate. Land Types: forest, grasslands, shrublands, savanna, natural and mixed, wetlands, barren. ~50 world regions Fuels: Ethanol maize, maize stover, sugarcane, switchgrass; Biodiesel and Renewable Diesel soya, microalgae; FT-Diesel - switchgrass, maize, stover; Butanol - maize 19

20 U.S. California Air Resources Board (CARB 2010) Analysis of Low Carbon Fuel Standard (LCFS) regulation GTAP-SOY (General Equilibrium) Scenarios: Change in biofuel production expected to occur in response to federal energy legislation and other regulation such as the LCFS from 2001 to Land Types: forest, grassland, crop Geographic Resolution: 111 world regions Fuels (iluc): Ethanol maize, sugarcane; Biodiesel soya 20

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22 Limitation of iluc Analyses and Methods Modeling systems Assumptions about the fuel (e.g. primary product?) Resolution of land changes and world regions Scope/interlinkages between economic sectors Coverage and bias issues with limited sources of data Most analysis are complex and therefore not easily transparent Scenario design Need to evaluate, critique, and improve upon all existing iluc evaluation methods. Meta-analysis would be a good starting point to inform future development. 22

23 Summary Part 1 Bioenergy is a part of complex interlinked system whose sustainability can in part be evaluated through LCA. Attributional analysis of GHGs for several bioenergy systems is fairly in depth and convergent on certain estimates Not much breadth in analysis among bioenergy or among systems within a fuel types Several iluc evaluation analyses have been completed or are on going. Roughly similar estimates, but hindered by limitations of the tool and assumptions about reality Land use is a big issue then energy and land use management offers a potential alternative. 23

24 Summary Part 2 Bioenergy has the opportunity to contribute to sustainable energy goals. However, the effects of bioenergy on environmental sustainability may be positive or negative depending upon local conditions, how criteria are defined, how actual projects are designed and implemented, among many other factors. There are likely tradeoffs between sustainability criteria. Policy has a role in influencing whether bioenergy with have on net positive or negative impacts. 24

25 References Dornburg, V., et al Biomass Assessment. Assessment of global biomass potentials and their links to food, water, biodiversity, energy demand and economy. p. 23.Report , CARB, California Environmental Protection Agency (EPA), "Proposed regulation to implement the low carbon fuel standard," vol. 1 (EPA, Sacramento, CA, 2009); CBES, 2009 Center for BioEnergy Sustainability, Oak Ridge National Laboratory.. Land-Use Change and Bioenergy: Report from the 2009 workshop, ORNL/CBES-001, U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy and Oak Ridge National Laboratory, Center for Bioenergy Sustainability ( EMBRAPA, Brazilian Agricultural Research Corporation (EMBRAPA), Ministry of Agriculture (MAPA), based on the Brazilian President Decree nº 6.961/2009; MAPA Norms Description nº 57/2009; related Resolutions of the National Monetary Congress (CMN) nº 3.813/2009 and nº 3.814/2009, and pending legislation nº 6.077/2009. EPA, 2010, Renewable Fuel Standard Program (RFS2) Regulatory Impact Analysis, EPA-420-R , February 2010, Melillo,J.M., Reilly,J.M.,. Kicklighter, D.W., Gurgel,A., Cronin,C.W., Paltsev, S., Felzer,B.S., Wang,X., Sokolov,A.,Schlosser, A. Indirect Emissions from Biofuels: How Important? Science, 326, Sparovek, G., Berndes, G., Kluga, I.L.F., Barretto, A.G.O. 2010(?).Status and challenges for Brazilian agriculture in relation to environmental legislation, in press 25