Environmental sustainability assessment of using forest wood for heat energy in Ireland

Wood from Irish forestry has potential for sustainably supplying some of Ireland's energy needs. This study used an environmental sustainability assessment methodology to assess how much heat energy could be supplied sustainably and the impacts on the environment in comparison to fossil fuels. Around 11% of the Irish land area is forested and around 31% of harvested forest wood is used for energy. Considering this, the steady-state sustainable supply of fuel wood energy from this area was estimated to be around 8.7% of the Irish heat primary energy demand in 2010. Thus, forest wood fuel is a limited resource and can only sustainably supply a small fraction of demand. Life cycle assessment showed that total environmental impact was about 10% of that for heating oil, although this did not include land requirement which is the dominant impact for wood fuel and limits its supply. Even though forest wood is “greener” than heating oil from a climate change perspective, there are a number of other impacts where it performs worse, in particular, emissions of particulate matter during wood combustion which contributed to the highest emissions impact from the life cycle.