Life cycle assessment of electricity transmission and distribution-part 1: power lines and cables

The purpose of this study is to provide life cycle inventory data and results for components of electrical grids to the larger community of life cycle assessment practitioners. This article is the first in a series of two, each focusing on different components of power grids. In part 1, the objects under scope are power lines and cables. Systems for overhead, underground, and subsea transmission are modeled here, including HVDC systems used in long-distance transmission. We use process-based life cycle assessment based on information provided by companies and in reports, Ecoinvent v2.2 as a background dataset and ReCiPe Midpoint Hierarchist perspective v1.0 as the impact assessment method. The average European power mix is used to model the electrical energy required to compensate power losses in the equipment. Under the assumption of European power mix, power losses are the dominant process for impacts of lines and cables in all impact categories, contributing with up to 99% to climate change impacts. An exception is the category of metal depletion, for which the production of metal parts is the most relevant process. After power losses, processes generating the most impacts for overhead lines are the production of metals for masts and conductors; production of foundations comes third. Recycling of metal parts shows benefits in all impact categories. For cables, infrastructure impacts are dominated by cable production, and recycling of cable materials does not always compensate for the other impacts generated at the end of life.