Energy crops in Ireland: Quantifying the potential life-cycle greenhouse gas reductions of energy-crop electricity

Abstract This study uses life-cycle assessment (LCA) to compare greenhouse gas (GHG) emissions from dominant agricultural land uses, and peat and coal electricity generation, with fuel-chains for Miscanthus and short-rotation-coppice willow (SRCW) electricity. A simple scenario was used as an example, where 30% of peat and 10% of coal electricity generation was substituted with co-fired Miscanthus and SRCW, respectively. Miscanthus and SRCW cultivation were assumed to replace sugar-beet, dairy, beef-cattle and sheep systems. GHG emissions of 1938 and 1346 kg CO 2  eq. ha −1  a −1 for Miscanthus and SRCW cultivation compared with between 3494 CO 2  eq. ha −1  a −1 for sugar-beet cultivation and 12,068 CO 2  eq. ha −1  a −1 for dairy systems. Miscanthus and SRCW fuel chains emitted 0.131 and 0.132 kg CO 2  eq. kWh −1 electricity exported, respectively, compared with 1.150 and 0.990 kg CO 2  eq. kWh −1 electricity exported for peat and coal fuel chains. 1.48 Mt CO 2  eq. a −1 was saved from electricity production, and 0.42 Mt CO 2  eq. a −1 was saved from displaced agriculture and soil C-sequestration. The total reduction of 1.9 Mt CO 2  eq. a −1 represents 2.8% of Ireland's 2004 GHG emissions, but was calculated to require just 1.7% of agricultural land area and displace just 1.2% of the dairy herd (based on conservative Miscanthus and SRCW combustible-yield estimates of 11.7 and 8.81 t ha −1  a −1 dry matter, respectively). A 50% increase in cultivation emissions would still result in electricity being produced with an emissi...