Forest biomass supply chains in Ireland: A life cycle assessment of GHG emissions and primary energy balances

Abstract

The demand for wood for energy production in Ireland is predicted to double from 1.5 million m 3 over bark (OB) in 2011 to 3 million m 3 OB by 2020. There is a large potential for additional biomass recovery for energetic purposes from both thinning forest stands and by harvesting of tops and branches, and stumps. This s tudy builds on research within the woodfor-energy concept in Ireland by analysing the ener gy requirements and greenhouse gas emissions associated with thinning, residue bundlin g and stump removal for energy purposes. To date there have been no studies on harvesting of residues and stumps in terms of energy balances and greenhouse gas emissions across the li fe cycle in Ireland. The results of the analysis on wood energy supply chains highlights tr ansport as the most energy and greenhouse gas emissions intensive step in the life cycle. This finding illustrates importance of localised production and use of forest biomass. Production of wood chip, and shredded bundles and stumps, compares favourably with both other sources of biomass in Ireland and fossil fuels.