Life cycle assessment (LCA) is a cradle-to-grave method that quantifies environmental impacts from materials extraction to waste disposal. It is frequently used in decision-support related to the energy sector. While LCA is broadly applied for greenhouse gas emissions, land use and ecological impacts are much less explored. Energy infrastructure associated with unconventional oil and gas development is complex, involving life cycle stages from production through processing/refining and transportation by pipelines to end use. In this presentation, the relationship between energy infrastructure and land impacts will be explored using a life cycle perspective.
The discussion will commence by introducing a comprehensive methodology to quantify the surface land disturbance associated with the life cycle of natural gas-fired electricity. Jordaan et al. (2017) developed a method for robust estimation of the life cycle land use of electricity generated from natural gas that was produced in the Barnett Shale of Texas. Approximately 500 sites in the Barnett shale of Texas were sampled across five life cycle stages (production, gathering, processing, transmission, and power generation). The analysis integrated inventories of infrastructure, satellite imagery and well-level production.
Results/Conclusions
Results specific to the surface land disturbance associated with electricity generated by combusting shale gas produced in the Barnett Shale region of Texas will be presented. For natural gas-fired electricity in the Barnett region of Texas, the total life cycle land use (0.62 m2/MWh, 95% confidence intervals +/-0.01 m2/MWh)) was dominated by midstream infrastructure, particularly pipelines (74%). The method was developed for broad application to other natural gas producing regions; such applications will be discussed.
A synthesis of the results relative to other findings on the life cycle land implications of unconventional oil and gas development will be introduced to set the stage for future research. Moving beyond metrics to better characterize the land disturbance of singular technologies, there is a need to better compare the relative life cycle impacts of different types of energy technologies, particularly renewable and non-renewable. Future research of land-related LCAs should also work towards more comprehensive inclusion of ecosystems impacts. Ultimately, methods are not yet mature, leaving much room for impactful research and findings.