Do electrical interties stimulate Canadian hydroelectric development? Using causal inference to identify second-order impacts in evolving sociotechnical systems

Abstract

Debates over the scope of environmental impact, life-cycle, and cost-benefit analysis frequently revolve around disagreements on the causal structure of complex sociotechnical systems. Environmental advocates in the United States have claimed that new electrical interties with Canada increase development of Canadian hydroelectric resources, leading to environmental and health impacts associated with new reservoirs. Assertions of such second-order impacts of two recently proposed 9.5 TWh year^-1 transborder transmission projects played a role in their suspension. We demonstrate via Bayesian network modeling that development of Canadian hydroelectric resources is stimulated by price signals and domestic demand rather than increased export capacity per se. However, hydropower exports are increasingly arranged via long-term power purchase agreements that may promote new generation in a way that is not easily modeled with publicly available data. Overall, this work suggests lesser consideration of generation-side impacts in permitting transborder transmission infrastructure while highlighting the need for higher resolution data to model the Quebec-New England-New York energy system at the project scale. More broadly, Bayesian analysis can be used to elucidate causal drivers in evolving sociotechnical systems to develop consensus for the scope of impacts to consider in environmental impact, life cycle, and cost-benefit analysis.