This work contributes to methods to integrate LCA, Risk Assessment and Benefit-cost analysis in order to better account for geographic heterogeneity in the environmental assessment of energy technologies. The first challenge considered is lack of data on locations of supply chain processes. This challenge is addressed by formulating a bounding analysis to characterize the range of impacts for locations within a region. The second issue is uncertainty in valuation models for marginal damages of air emissions. The approach is to consider all available models, construct a baseline but also estimate results for alternate choices. The third challenge addressed is uncertainty in the social cost of carbon, addressed by recasting a benefit-cost analysis as finding the breakeven social cost of carbon required to make a technology beneficial, per location.
The method is applied to assessment of Carbon capture and storage (CCS) on coal plants in the United States. CCS for coal power plants reduces onsite carbon dioxide emissions, but affects other air emissions on and offsite. This research assesses the net societal benefits and costs of Monoethanolamine (MEA) CCS, valuing changes in emissions of CO2, SO2, NOX, NH3 and particulate matter (PM), including those in the supply chain. Geographical variability and stochastic uncertainty for 407 coal power plant locations in the U.S. are analyzed. The results show that the net environmental benefits and costs of MEA CCS depend critically on location. For a few favorable sites of both power plant and upstream processes, CCS realizes a net benefit (benefit-cost ratio > 1) if the social cost of carbon exceeds $51/ton. For much of the U.S. however, the social cost of carbon must be much higher to realize net benefits from CCS, up to a maximum of $910/ton. While the social costs of carbon are uncertain, typical estimates are in the range of $32-220/ton, much lower than the breakeven value for many potential CCS locations. Increased impacts upstream from the power plant can dramatically change the social acceptability of CCS and needs further consideration and analysis.