Biomass and Bioenergy Approaches to Assessing Greenhouse Gas Mitigation Potential Carly Green 20 November 2003IEA Bioenergy Task 38 National Meeting - Ireland University College Dublin

Introduction What is biomass? Why calculate GHG benefits –The Carbon Cycle –Options for biomass How are GHG benefits calculated –Life Cycle Analysis Case Studies

What is biomass? Accumulates in living vegetation following photosynthesis Important pool in the carbon cycle Exists in many forms Contributes to other pools within the global system

The Carbon Budget Contribution Emitted (source) Absorbed (sink) Burning fossil fuels6.3 Land use change1.6 Enhanced vegetation growth 3.0 Ocean-atmosphere exchange 1.7 Total Balance3.2 (Source: Broadmeadow and Matthews, 2003)

Greenhouse gas mitigation options Fuel for Energy Dedicated Sources (i.e. by-products of other activities) Dependant Sources (i.e. energy crops grown specifically for food ) Carbon Sink Wood Products

Fuel for Energy Long use history (i.e. centuries) –Currently contributes 14% to the global energy requirements More efficient use through modern technology –Solid liquid and gas Capable of replacing all fossil fuel energy forms

Fuel for Energy (cont.) a. CO 2 captured by growing crops and forests ‘Recycling of carbon’ Source: IEA Bioenergy Task 38 d. Released C from burning biomass is made available again. c. C in harvested biomass is transported to the power station b. O 2 released and C is stored in the biomass of plants

Carbon Sink Recent Policy has focused on this option –Kyoto Protocol Article 3.3 Increase carbon stock in various pools –Aboveground / belowground and soil Time Dependant –Land use change

Carbon Stock Dynamics Managed as a carbon sink a. Establishment b. Full vigour c. Mature Phase d. Longterm equilibrium Managed as commercial forest Periodic felling indicated by arrows Over several rotations carbon stocks niether increase of decrease Accumulation balanced by removals for wood products, bioenergy etc

Wood Products Product replacement Sink Fuel at end of life

Why calculate GHG benefits Analyse potential Quantify benefits Compare options Quality decision

Life cycle analysis considerations Other greenhouse gases Task 38 standard methodology for calculating GHG emissions Source: IEA Bioenergy Task 38 Carbon stock dynamics Trade-offs and synergies Leakage Permanence Emissions factors By-products Efficiency Upstream/downstream emissions

Constraints Must compare systems within same system boundary Task 38 standard methodology for calculating GHG emissions Source: IEA Bioenergy Task 38 Information (data) sources – Boundary selection – Restricted analysis

Bioenergy Case Study 1 GORCAM output Source: IEA Task 38

Bioenergy Case Study 2a Ethanol production in Brazil vs United States Potential CO 2 emissions avoided –Brazil 5.6 MtC/yr –United States 0.59 MtC/yr Source: Kheshgi and Marland, 2000

Bioenergy Bioenergy output to fossil energy input –Forestry and agriculture (25-50 : 1) –Liquid energy (4-5 : 1) Source: Marland, 1999

Bioenergy Case Study 2b natural gas power plant with gas and steam turbine Greenhouse gas emission factor [g CO 2-eq. kWh electricity -1 ] 51,1 459 CO 2-eq wood chips power plant with steam turbine 34,5 16, ,9 CO 2 N2ON2O Greenhouse gas 0,307 0,62 CH 4 Austria: Fuel cycle analysis of Power plants Source: Jungmeier et al, 1999

Canada: Total Forest Ecosystem Carbon Modelling ( ) Source: Kurz and Apps, 1999 Sink Source Case Studies - Sink

Case Study - Sink Typical radiata pine regime New Zealand: Long-term average carbon density Source: IEA Task 38, 2003

Case Study – Wood Products 1 kilometre of transmission line Life 60 years Including disposal Emission in tonnes of CO 2 equivalent to construct Product Replacement Source: Matthews and Robertson, 2002

Case Study – Wood Products Canada:Forest Products Carbon Storage Source: IEA Task 38, 2003

Preferential Use Source: Matthews and Robertson, 2002