Embodied transport energy analysis of imported wood pellets

Abstract

The Irish Government has recently introduced a series of capital grants to boost the uptake of domestic wood-pellet technologies in order to reduce greenhouse gas emissions. These have proved popular and have encouraged a significant number of people to switch from gas- and oil-fired boilers to the cleaner fuel. The demand for wood-pellets has, however, greatly exceeded the national capacity for production. The market for wood pellets elsewhere in Europe is also tight and, consequently, a large proportion of Irish pellets are sourced in Canada. This presents possible problems: the carbon emissions associated with long-distance transport may significantly offset the expected environmental benefits; and the resulting need to purchase carbon credits may impact on the Irish Governments rationale for promoting the technology. This paper describes a process-based embodied energy analysis which indicates that the difference in transport embodied energy and CO2 emissions between imported and domestically produced wood pellets is up to 1,403MJ/tonne and 108kg/tonne respectively. Imported pellets have up to four times more embodied energy than those that are domestically-produced. Although this erodes their environmental credentials, it is still a significant improvement when compared to displaced conventional fuels; for example, it is equivalent to 22 of natural gas CO2 emissions. An economic analysis of present value indicates that the short-term cost to the Irish exchequer of these increased emissions is small.