CLCA for Assessing Environmental Impacts of Power Sector in the GHG Policy Context

Purpose: Current greenhouse gas (GHG) policy aims at reducing emissions from power sector. However, there are some known trade-offs of GHG emission reductions, in terms of other types of environmental impacts and impacts on other economic sectors. Consequential life cycle assessment (CLCA) has been developed to assess the environmental impacts of the power sector in relation with changes in the policy and its indirect impacts on other economic sectors. Methods: A systematic review of CLCA method is conducted in the power sector. CLCA studies since 2005 are reviewed in terms of obtained results and methodology to identify whether CLCA is a more suitable approach for assessing environmental impacts of power sector in the context of GHG policy intervention, compared to attributional life cycle assessment (ALCA). Results and discussion: With CLCA the total environmental impacts/benefits of power system change when indirect impacts are accounted. The variations between the total environmental impacts quantified with CLCA and ALCA range widely from inconsiderable difference (less than 5%) to 200%, depending on the investigated product system. These variations originate from CLCA’s modelling principles of expanding the system boundary and the inclusion of socio-economic interactions. With the expansion of system boundary, CLCA covers affected products and accounts for their relevant environmental impacts, which makes the obtained results comprehensively quantified. At the same time, the inclusion of socio-economic interactions in CLCA improves its capability of identifying the connections between environmental impacts and social-economic changes such as economic growth and consumer behaviours.