Stockholm Environment Institute

Transcription

1 Biomass Energy: Challenges and Perspectives Forest Soils and Productivity, November 18, 2011 Carrie Lee, SEI - US Stockholm Environment Institute Independent international research organization working on sustainable development. HQ in Stockholm, Sweden with centers in the US, UK, Estonia, Tanzania and Thailand. Applied scientific research: bringing science to policy makers. 170 staff (25 in the U.S.). Funders: Swedish and US Governments, UNDP, UNEP, UNFCCC, foundations, national & local governments and NGOs US Center of SEI is an independent non profit research institute affiliated with Tufts University in Massachusetts. Web sites: us.org and international.org Overview What is Bioenergy? Global energy demand Conflicting demands Potential impacts Global supply Does bioenergy provide a climate benefit? Example of analysis of life-cycle GHG from woody biomass residues in PNW 1

2 What is bioenergy? What is bioenergy? 1 st generation 3 rd generation 2 nd generation? 4 th generation Biomass Energy Demand 450 ppm scenario reference scenario Source: IEA 2009 and UNFCCC

3 Global Energy Demand Comparison of Estimates of Technical Potential of Energy Crops estimates of technical potential of energy crops primary energy demand EJ/yr energy crop demand (in carbon constrained future) 2050 primary energy demand (in carbon constrained future) Published Studies Potential Bioenergy Impacts Natural Resources Ecosystem Services Positive Global Climate low carbon fuel (?) surface albedo Negative air pollution water pollution water demand soil fertility loss biodiversity loss forest cover loss LUC iluc Food Security crop variety research food availability food prices nutrition Social and Economic Security employment energy security land tenure rights smallholder vs. largescale production 3

4 Global Bioenergy Conflicts Bioenergy demand bioenergy imports Bioenergy export production Global Bioenergy Conflicts Bioenergy demand domestic production Food export production Global Bioenergy Conflicts Bioenergy demand domestic production Food prices rise 4

5 Bioenergy Conflicts Competing demands for food, feed, fuel: Population growth 1 billion more people in sub-saharan Africa by 2050 (UN, 2009) Food demand 190% increase in cereals in sub-saharan Africa by 2050 (Msangi and Rosengrant, 2009) Feed demand doubling of global meat and milk demand by 2050 (FAO, 2006) There is always a climate benefit There is a climate benefit only if... At landscape level carbon stocks are increasing 5

6 There is a climate benefit only if... At stand level carbon stocks are replaced and increasing There is a climate benefit only if... Using residues Current Common Practices On-site Decomposition On-site Combustion Regional Air Quality Maintenance of ambient air quality Regional Haze Nuisance Smoke Air Toxics 6

7 Biomass Energy: Emissions from Alternatives for Woody Biomass Residues System Emissions = Sum of process step and use disposal soil residential amendment energy industrial energy industrial liquid fuel feedstock Example: Life-cycle boundary of pelletization & combustion in pellet stove gathering processing transport pellet processing distribution combustion in pellet stove Net Emissions = System Avoided + Alternate disposal soil residential amendment energy industrial energy industrial feedstock liquid fuel New Product System Emissions pelletization & combustion in pellet stove wood stove furnace electric heat Displaced Existing Product Emissions * avoided avoided alternate * Analysis assumes fuel wood is diverted to an alternate use 7

8 Life cycle system boundary Forest Residue Alternatives Alternative Displaced Existing Product Options 1. Disposal decomposition combustion N/A 2. Soil amendment mulch wood mulch; other organic mulch composting wood bulking agent; other organic bulking agent biochar (+ energy generation) electricity 3. Residential energy fireplace fuel wood EPA certified stove fuel wood; natural gas; electricity; pellet stove heating oil 4. Industrial energy industrial boiler: fossil fuel natural gas; diesel; residual oil industrial boiler: biomass hog fuel integrated gasification and combustion natural gas; diesel; residual oil; electricity cogenerator electricity 5. Industrial feedstock pulp or paper pulp + electricity 6. Liquid fuel cellulosic ethanol gasoline + electricity ethanol by gasification gasoline System Process Step Emissions 8

9 Net GHG Emissions fuel wood alternate wood stove fuel wood combustion fuel wood decomposition electric heat natural gas (furnace) heating oil (furnace) Emissions Calculator tool Woody Biomass Emissions Calculator spreadsheet tool, allows users to adjust inputs to generate estimates for project specific circumstances, or to cast the consequential LCA relative to a different reference option. Questions? Please contact me at: Carrie Lee carrie.lee@sei us.org 9