Forest biomass utilization for energy production: opportunities and concerns

Transcription

1 Forest biomass utilization for energy production: opportunities and concerns David Paré, Evelyne Thiffault Canadian Forest Service Nova Scotia Energy Research & developement forum 2010 Halifax May 26-27

2 Lumber Bioenergy Pulp Forest harvest residues as a source of energy: is this a good idea? Source: Groupement forestier de l est du lac Témiscouata

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4 Plan 1. Bioenergy in the context of world energy supply 2. Issues --- can it really help reducing our GHG emissions?--- How about Ecosystem sustainability? 3. A path to building a success story Production of CO2 by human activities

5 We used to get most our energy from bioenergy sources. What role can it play today? From Hughes 2007 NRCan

6 Renewed interest for renewables: Climate change issues; Energy security; Economical issues and biomass is currently the big player in renewable E global primary energy consumption (IEA 2009) Renewable (IEA 2009) 100 Ren, Oil, Nucl, 6 Coal, Other R Hydro Bioenergy 87% 77 wood Gas,

7 Biomass energy: land intensive (Sci & Vie 2008) Area (km2) required to produce 3.65 GW electricity (a large city: Paris) 0 nuclear solar hydro wind biomass

8 Forest residues: low density energy, transportation distances are critical Source Dominic Roser METLA

9 Technical potential from renewable energy (EJ) From IEA 2008 Solar Wind Hydro Bioenergy Why biomass? It is already being produced out there, in real ecosystems, you don t need much infrastructure to get it although it is not dense both in terms of energy content nor of energy produced per land area

10 Bioenergy: is the cure worse than the disease? (Doornbosch 2007 round table on sustainable development, OECD) Issues outlined by IEA 2008: Higher food prices competition with food crops Expensive option for energy security Limited GHG reduction benefits Do not meet their claimed environmental benefits because may not be produced sustainably Accelerating deforestation Negative impact on biodiversity Compete for water in some region

11 Ecological footprint of forest biomass utilization?

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13 Lignocellulose based fuels are definitely on the positive side of the equation

14 Biofuels for transportation from woody materials are definitely good options for reducing contribution to GHG but direct heating, CHP or co-firing are superior options in terms of energy use and of GHG reductions Estimates of E used for heating and transportation compared to technical potential energy from forest harvest residues in Canada (EJ) Paré Bernier Thiffault Titus in prep HEATING DEMAND TRANSPORTATION RESIDUE Roadside+urban Transportation Commercial-water Commercial space Residential-water Residential-space

15 Nova scotia: Forest Residues supply vs potential uses (PJ/y) NRCan Office of Energy year 2007, Sidders Supply use mill roadside urban heating-r passenger freight

16 Forest biomass and GHG reduction The use of forest biomass can definitively contibute to reducing GHG emissions It ranks top among other types of biofuel feedstocks even better when used for generating heat and when use locally

17 Sustainability of forest biomass harvesting

18 Wholetreeharvestedsite Slash No slash Slash pile effect

19 Harvest residues can be used as protective mats for machinery. This protection is lost when residues are to be collected for bioenergy purposes.

20 Residue harvesting also reduces soil cover and can increase erosion.

21 More machinery entries on the forest site increase the risk of soil rutting/compaction.

22 Tree growth

23 Field studies in the boreal forest of Quebec years after harvest Whole tree harvesting Stem-only harvesting Loss of growth (20% after 20 yrs): Jack pine Black spruce Balsam fir Coarse sandy soil Medium textured till soil Reduced OM, CEC, Cations Ca Mg Source: Thiffault et al. 2006, SSSAJ,

24 Field trials in the Maritimes Whole-tree harvesting Stem-only harvesting NB (9 yrs) NS (7 yrs) PEI (8yrs) 0 Tree height (cm) bs WTH Deersdale NB bs STO Deersdale NB jp WTH Deersdale NB jp STO Deersdale NB rs WTH Dickey Lk Rd NS rs STO Dickey Lk Rd NS ns WTH Dickey Lk Rd NS ns STO Dickey Lk Rd NS rs WTH West River Stn NS rs STO West River Stn NS ns WTH West River Stn NS ns STO West River Stn NS rs WTH West Brook Rd NS rs STO West Brook Rd NS bs WTH West Brook Rd NS bs STO West Brook Rd NS wp WTH PEI wp STO PEI ws WTH PEI ws STO PEI Data courtesy of: Dr Taumey Mahendrappa

25 Some examples of sensitive sites (see Thiffault et al SSSAJ) Coarse sandy soils Thin soils Credit: Sutherland 2005

26 What are the risks? Loss of Biodiversity Loss of carbon Compaction and rutting Erosion Loss of nutrients Loss of tree growth

27 Which site conditions are sensitive to these risks? Loss of Biodiversity Loss of carbon Compaction and rutting Erosion Loss of nutrients Loss of tree growth sensitive wildlife habitat coarse soil peatland steep slope peatland???? rare plant communities excessively drained soil Poorly drained soil shallow soil shallow soil coarse soil excessively drained soil poor or acidic soil

28 What guidelines for biomass harvesting should be applied to these sites? Loss of Biodiversity Loss of carbon Compaction and rutting Erosion Loss of nutrients Loss of tree growth sensitive wildlife habitat coarse soil peatland steep slope peatland???? rare plant communities excessively drained soil Poorly drained soil shallow soil shallow soil coarse soil excessively drained soil poor or acidic soil No harvest Winter harvest or retention of large debris Winter harvest No harvest No Harvest OR Winter harvest/ Retention of of residues

29 This info can be built in GIS tools to assess sustainable availability of biomass: Example for Abitibi (western Quebec) Area of productive forest: 30% = Sensitive 70% = Suitable

30 Regulation Adaptive Management Monitoring Map sensitive sites (avoidancemitigation)

31 A standard protocol for monitoring the impacts of residue harvesting Boundary of main plot Boundary of main plot Paired plots Centre 20 m Centre 20 m Plot with residues Plot without residues

32 GUIDELINES Establishing Permanent Plots for Monitoring the Environmental Effects of Forest Biomass Harvesting (Thiffault, Paré, Dagnault, Morissette to be released 2010)

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34 Take-home messages Using forest harvest residues as a source of energy makes sense as an option to reduce our GHG contributions (scored top among other bioenergy feedstocks) but for best usage, one should consider production of heat and limited transportation distances. A path to sustainability: Develop a strategy based on current knowledge + Monitor + Validate tools to rate sensitivity + Review regulations.