Now showing 1 - 10 of 18
  • Publication
    Transport sector in Ireland: Can 2020 National targets drive indigenous biofuel production to success?
    Ireland's transport sector consumes just slightly less than one third of all energy in Ireland and is heavily dependent on oil imports, especially diesel. The European Union has set targets that are to be met by 2020, in order to guarantee a sustainable future for Europe and assure security of energy supply. There is an increase of biofuel usage in the transport sector, to reduce greenhouse gas emissions and encourage indigenous production of renewable sources. Currently, Ireland has only two licensed suppliers of biodiesel. The Irish government has issued a number of policy support mechanisms, and while that has increased the use of biofuels in Ireland, it has not necessarily aided the domestic suppliers of biofuels. The aim of this paper is to detail the existing policies and support mechanisms in Ireland and to examine whether it is possible for Ireland to produce biofuels indigenously while meeting the 2020 targets and competing with the alternative conventional imports. Alternatives to the current supply scenario will be considered, including alternatives such as electric vehicles, recovered waste vegetable oils, and grass gasification for biomethane for natural gas vehicles.
    Scopus© Citations 5  1224
  • Publication
    Feasibility Study of Carbon Dioxide Plume Geothermal Systems in Germany−Utilising Carbon Dioxide for Energy
    To manage greenhouse gas emissions, directives on renewable energy usage have been developed by the European Commission with the objective to reduce overall emissions by 40% by 2030 which presents a significant potential for renewable energy sources. At the same time, it is a challenge for these energy technologies which can only be solved by integrated solutions. Carbon capture and storage combined with geothermal energy could serve as a novel approach to reduce CO2 emissions and at the same time facilitate some of the negative impacts associated with fossil fuel-based power plants. This study focuses on the technical and economic feasibility of combining these technologies based on a published model, data and market research. In the European Union, Germany is the most energy intensive country, and it also has an untapped potential for geothermal energy in the northern as well as the western regions. The CO2 plume geothermal system using supercritical carbon dioxide as the working fluid can be utilized in natural high porosity (10–20%) and permeability (2.5 × 10−14–8.4 × 10−16 m2) reservoirs with temperatures as low as 65.8 ◦C. The feasibility of the project was assessed based on market conditions and policy support in Germany as well as the geologic background of sandstone reservoirs near industrialized areas (Dortmund, Frankfurt) and the possibility of carbon capture integration and CO2 injection. The levelized cost of electricity for a base case results in € 0.060/kWh. Optimal system type was assessed in a system optimization model. The project has a potential to supply 6600/12000 households with clean energy (electricity/heat) and sequester carbon dioxide at the same time. A trading scheme for carbon dioxide further expands potential opportunities.
      169Scopus© Citations 14
  • Publication
    Life cycle assessment of biomass-to-energy systems in Ireland modelled with biomass supply chain optimisation based on greenhouse gas emission reduction
    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.
      794Scopus© Citations 46
  • Publication
    Energy requirements and environmental impacts associated with the production of short rotation willow (Salix sp.) chip in Ireland
    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.
    Scopus© Citations 44  651
  • Publication
    Miscanthus production and processing in Ireland: An analysis of energy requirements and environmental impacts
    The environmental impact of bioenergy supply systems can be determined using life cycle assessment methodologies. This study focuses on the impact of production of Miscanthus pellets and briquettes, potentially used to satisfy renewable energy requirements in Ireland. The impact categories considered are particularly important when assessing bioenergy systems; global warming potential, acidification potential, eutrophication potential, and energy demand. The scope of the study incorporates Miscanthus cultivation, harvest, processing and transport to a biomass distributor. The aim of the research is to evaluate the effects of changes in keys variables on the overall environmental impacts of the system. The scenarios examined include replacement of synthetic fertilisers with biosolids, Miscanthus processing by pelleting and briquetting, and transport distances of 50 and 100 km. Results indicate that maintenance and processing of the Miscanthus crop have the most environmental impacts with transport having less of an effect. Replacing synthetic fertiliser with biosolids results in a reduction in global warming potential of 23–33% and energy demand of 12–18%, but raises both acidification and eutrophication potential by 290–400% and 258–300%, respectively. Pelleting of Miscanthus requires more energy than briquetting, hence has higher impacts in each category assessed. Increasing the transport distance from 50 to 100 km, results in a small increase in each impact category. Miscanthus briquette production compares favourably with wood pellet, kerosene, and coal production, with Miscanthus pelleting proving more environmentally damaging.
    Scopus© Citations 47  900
  • Publication
    The Evaluation of Flash Point and Cold Filter Plugging Point with Blends of Diesel and Cyn-Diesel Pyrolysis Fuel for Automotive Engines
    The production of synthetic fuels from alternative sources has increased in recent years as a cleaner, more sustainable source of transport fuel is now required. The European Commission has outlined renewable energy targets pertaining to transport fuel which must be met by 2020. In response to these targets Ireland has committed, through the Biofuels Obligation Scheme of 2008, to producing 3% of transport fuels from biofuels by 2010 and 10% by 2020. In order to be suitable for sale in Europe, diesel fuels and biodiesels must meet certain European fuel specifications outlined in the EN 590:2009 standard. The aim of this paper was to prepare blends of varying proportions of synthetic diesel (Cyn-diesel) fuel, produced from the pyrolysis of plastic, vs regular fossil diesel. The flash point (°C) and cold filter plugging point (°C) of these blends as well as of the conventional petroleum diesel fuel were analysed in relation to compliance with the European fuel standard EN 590. The results confirmed that blending of Cyn-diesel with conventional petroleum diesel has a highly significant effect on the properties of the resulting fuel blend. The results show that by increasing the Cyn-diesel content of the blend, the flash point of the blend decreases and the cold filter plugging point increases. Furthermore, comparing the fuel blends to EN 590 specifications has highlighted significant trends. The cold filter plugging points of all of the fuel blends are in compliance with EN 590 specifications. However, only blends of up to, and including, 40% Cyn-diesel are in compliance with EN 590 specifications for flash point. This analysis shows that a blend of 40% Cyndiesel is in compliance with all of the EN 590 specifications examined, and as such could be placed on the European fuel market (provided that the blend meets the requirements for the other properties in the EN 590 specification). This finding highlights the potential for Cyn-diesel blends to be incorporated into the European and national renewable energy targets.
    Scopus© Citations 9  538
  • Publication
    Forest Biomass Supply Chains in Ireland: A Life Cycle Assessment of GHG Emissions and Primary Energy Balances
    The demand for wood for energy production in Ireland is predicted to double from 1.5 million m3 over bark (OB) in 2011 to 3 million m3 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 study builds on research within the wood-for-energy concept in Ireland by analysing the energy requirements and greenhouse gas emissions associated with thinning, residue bundling 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 life cycle in Ireland. The results of the analysis on wood energy supply chains highlights transport 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.
    Scopus© Citations 65  1056
  • Publication
    Investigation of the potential impact of the Paris Agreement on national mitigation policies and the risk of carbon leakage; an analysis of the Irish bioenergy industry
    A criticism of production-based reporting and accounting of greenhouse gas emissions, as implemented under the UNFCCC and Kyoto Protocol, is the risk of mitigation measures adoption in one country to reduce national emissions, leading consequentially to the displacement of the source activity to other jurisdictions, thus resulting in an increase in net global emissions referred to as 'carbon leakage'. An important outcome of the 21st Conference of the Parties (COP) to the 1992 UNFCCC may be 'plugging' of carbon leakage. This study examined the bioenergy industry in Ireland to determine the extent of existing carbon leakage due to national energy policy and to establish if measures identified within the relevant intended nationally determined contributions will result in plugging of carbon leakage. The study focused on co-firing of biomass with peat, the major use of biomass for energy generation in Ireland. The results show that significant levels of carbon leakage occur due to reliance on imported biomass feedstocks to meet co-firing targets under Irish energy policy. In the post-COP21 scenario, one of the three Intended Nationally Determined Contributions analysed contains a measure which has the potential to reduce greenhouse gas emissions from imported biomass by 32%, highlighting the potential of the Paris Agreement to reduce carbon leakage.
    Scopus© Citations 29  765
  • Publication
    A Feasibility Assessment of Photovoltaic Power Systems in Ireland; a Case Study for the Dublin Region
    Photovoltaic (PV) power generation is one of the cleanest sources for producing renewable energy; however uptake on the Irish renewable energy market to date has been low. There is a lack of support for solar PV systems in Ireland; there is currently no solar PV energy feed-in-tariff as there are for other renewable energy systems in Ireland. Despite the current lack of support, the Government has indicated that support for the uptake of solar PV installations will be provided through the provision of a feed-in tariff in the future. The aim of this study was to determine the feasibility of installing PV systems under Irish climatic conditions at a location based in Dublin, Ireland, from a technical, environmental and economic point of view. This was achieved by carrying out a life cycle assessment of potential environmental impacts, and analysis of energy and economic payback times relating to the proposed PV system. Four possible renewable feed-in-tariffs (based on existing feed-in-tariffs for other renewable energy systems) were considered to determine the effect of such tariffs on the overall economics of the proposed PV system. Results show that life cycle GHG emissions are 69 g CO2-eq per kWh generated by the system, significantly lower than the current electricity grid mix emissions of 469 g CO2-eq per kWh. It will take 5.23 years of operation of the solar plant to generate the same amount of energy (in terms of primary energy equivalent) that was used to produce the system itself. The economic payback time varies from 19.3 and 34.4 years depending on the rate of renewable energy feed-in-tariff applied. The costs for the production of PV electricity in this study are higher than is usual in countries where the solar PV market is more developed, e.g., Germany, due to constraints with building integration and lack of experienced PV installers. As more PV is deployed, the Irish PV installer base will increase and ‘learning by doing’ effects will allow installers to install projects more efficiently and quickly under Irish conditions, leading to significantly reduced costs.
    Scopus© Citations 28  1108
  • Publication
    Greenhouse gas and energy based life cycle analysis of products from the Irish wood processing industry
    The timber industry in Ireland is an important producer of wood products for export and indigenous use, and supplies significant volumes of sawmill co-products as biomass for energy generation. This research expands existing knowledge on the environmental impacts of wood supply chains in Ireland by widening the analysis to incorporate the wood processing stage. The study determines and analyses energy and material inputs in the production of several timber products; sawnwood, wood chip, wood-based panel (WBP) boards and wood pellets, with an analysis of the resulting greenhouse gas emissions. Forestry operations and transportation make an important contribution to overall emissions. Electricity usage is responsible for the majority of emissions in sawmilling. Integration of combined heat and power (CHP) systems with sawmilling and pellet manufacture reduces greenhouse gas (GHG) emissions. The penetration of renewables in the Irish national grid mix is forecast to increase by 2020 in line with EU renewable energy targets. Analysis shows that the forecast fall in the carbon intensity of the grid will have a positive effect on the reduction of GHG emissions from the wood processing supply chains. Wood energy products compare favourably with other sources of biomass energy and with fossil fuels.
      1254Scopus© Citations 54