Benchmarking Environmental Impacts of Peat Use for Electricity Generation in Ireland - A Life Cycle Assessment

The combustion of peat for energy generation accounts for approximately 4.1% of Ireland’s overall greenhouse gas (GHG) emissions, with current levels of combustion resulting in the emission of 2.8 Mt of CO2 per annum. The aim of this research is to evaluate the life cycle environmental impacts of peat use for energy generation in Ireland, from peatland drainage and industrial extraction, to transportation, combustion, and subsequent after-use of the cutaway area, utilising Irish-specific emission factors. The environmental impacts considered are global warming potential, acidification potential, and eutrophication potential. In addition, the cumulative energy demand of the system is evaluated. Previous studies on the environmental impact of peat for energy in Ireland relied on default Intergovernmental Panel on Climate Change (IPCC) emission factors (EFs). This research utilises Irish-specific EFs and input data to reduce uncertainty associated with the use of default IPCC EFs, and finds that using default IPCC EFs overestimates the global warming potential when compared to Irish-specific EFs by approximately 2%. The greatest contribution to each of the environmental impacts considered arises from emissions generated during peat combustion, which accounts for approximately 95% of each of the environmental impact categories considered. Other stages of the life-cycle, such as impacts emanating from the peat extraction area, fossil fuel usage in harvesting and transportation machinery, and after-use of the cutaway area have much smaller effects on overall results. The transformation of cutaway peatlands to different after-use alternatives has the potential to mitigate some of the effects of peatland degradation and peat combustion.