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Two cable logging systems were reviewed to compare the efficiency of potential biomass extraction from remote forest sites in Ireland based on productive machine hour (PMH) and unit cost of operation (€/m3). Three operational scenarios (SC) were analysed where SC I was a three man crew operation (choker setter, the carriage operator and unhooking chokers). SC II was a variation of this with a two man crew operation. SC III was operating radio controlled chokers there was a two man crew (choker setter and carriage operator). The study aims to assess how operations in Ireland perform against previous known cable studies to determine whether the cost of timber extraction on remote forest sites inaccessible for mechanised felling, has a future given the increased demand for wood fibre in Ireland, both from the saw milling industries and the wood for energy sector. The volume per PMH was recorded at 17.97 for SC I, 15.09 for SC II and 20.58 m3 for SC III. The difference in productivity versus SC III remote controlled chokers is 5.49 m3/PMH for SC II crew and 2.61 m3/PMH for SC I. The decrease in total volume extracted from SCs I and II versus SC III was recorded at 15.69 m3 (15%) and 32.97 m3 (36%) product respectively. In value terms, the unit cost (€/m3) varied from 6.29 (SC I) to 6.43 (SC II) to 4.57 (SC III). When looking at the production unit costs of normal wood energy supply chains in Ireland, the figures are similar ranging from 3.17 €/m3 to 8.01 €/m3. The value of the end product of course will always determine which market the eventually goes to but given that cable log wood fibre has been unthinned and unmaintained then the biomass sector may be an ever increasing demand point in the search for increased woody biomass given that the unit costs can be competitive with other wood energy supply chains. [ABSTRACT FROM AUTHOR]

Willow Salix sp. is currently cultivated as a short rotation forestry crop in Ireland as a source of biomass to contribute to renewable energy goals. The aim of this study is to evaluate the energy requirements and environmental impacts associated with willow ( Salix sp .) cultivation, harvest, and transport using life cycle assessment ( LCA). In this study, only emissions from the production of the willow chip are included, end-use emissions from combustion are not considered. In this LCA study, three impact categories are considered; acidification potential, eutrophication potential and global warming potential. In addition, the cumulative energy demand and energy ratio of the system are evaluated. The results identify three key processes in the production chain which contribute most to all impact categories considered; maintenance, harvest and transportation of the crop. Sensitivity analysis on the type of fertilizers used, harvesting technologies and transport distances highlights the effects of these management techniques on overall system performance. Replacement of synthetic fertilizer with biosolids results in a reduction in overall energy demand, but raises acidification potential, eutrophication potential and global warming potential. Rod harvesting compares unfavourably in comparison with direct chip harvesting in each of the impact categories considered due to the additional chipping step required. The results show that dedicated truck transport is preferable to tractor-trailer transport in terms of energy demand and environmental impacts. Finally, willow chip production compares favourably with coal provision in terms of energy ratio and global warming potential, while achieving a higher energy ratio than peat provision but also a higher global warming potential. [ABSTRACT FROM AUTHOR]

The threat of increasing fuel prices and climate change necessitates the need for clean, renewable and independent energy sources. A GIS (Geographical Information Systems) model was developed using ArcGIS 9.2 to analyze the availability of non-woody biomass (wheat, oat, barley and rape straw, willow and miscanthus) for pellet production in Ireland. Utilization within the heating and electricity sector would displace currently used fossil fuels with cleaner, carbon neutral non-woody residues. The aim of the analysis was to determine the total hectares of biomass within Ireland and compute the potential non-woody biomass yield. The greatest potential source of biomass for pelleting is cereal straw. Within the Republic of Ireland the South-East, South-West and Mid-East of Ireland have the greatest biomass yield for pellet production and likely to be most economically viable. Non-woody biomass has a realistic potential to displace fossil fuels within the heating and electricity sector resulting in CO2 mitigation. [ABSTRACT FROM AUTHOR]

The energy sector is the major contributor to GHG (greenhouse gas emissions) in Ireland. Under EU Renewable energy targets, Ireland must achieve contributions of 40%, 12% and 10% from renewables to electricity, heat and transport respectively by 2020, in addition to a 20% reduction in GHG emissions. Life cycle assessment methodology was used to carry out a comprehensive, holistic evaluation of biomass-to-energy systems in 2020 based on indigenous biomass supply chains optimised to reduce production and transportation GHG emissions. Impact categories assessed include; global warming, acidification, eutrophication potentials, and energy demand. Two biomass energy conversion technologies are considered; co-firing with peat, and biomass CHP (combined heat and power) systems. Biomass is allocated to each plant according to a supply optimisation model which ensures minimal GHG emissions. The study shows that while CHP systems produce lower environmental impacts than co-firing systems in isolation, determining overall environmental impacts requires analysis of the reference energy systems which are displaced. In addition, if the aims of these systems are to increase renewable energy penetration in line with the renewable electricity and renewable heat targets, the optimal scenario may not be the one which achieves the greatest environmental impact reductions. [ABSTRACT FROM AUTHOR]

In the coming years, Ireland will continue to face an increasing demand for wood biomass as a renewable source of energy. This will result in strained supply/demand scenarios, which will call for new planning and logistics systems capable of optimizing the efficient use of the biomass resources. In this study, a linear programming tool was developed which includes moisture content (MC) as a driving factor for the cost optimisation of two supply chains that use short wood and whole trees from thinnings as material feedstock. The tool was designed and implemented to analyse the impact of moisture content and truck configurations (5-axle and 6-axle trucks) on supply chain costs and spatial distribution of the supply materials. The results indicate that the inclusion of wood chips from whole trees reduces the costs of wood energy supply in comparison with only producing wood chips from short wood to satisfy the demand, with 9.8% and 10.2% cost reduction when transported with 5-axle and 6-axle trucks respectively. Constraining the MC of the wood chips delivered to the power plant increases both transport and overall supply chain costs, due, firstly to an increase in the haulage distance and secondly, to the number of counties providing the biomass material. In terms of truck configuration, the use of 6-axle trucks resulted in a 14.8% reduction in the number of truckloads and a 12.3% reduction in haulage costs in comparison to the use of 5-axle trucks across the MC scenarios analysed. [ABSTRACT FROM AUTHOR]