Power decarbonation in Northeastern America: the benefits of multi-stage planning and regional cooperation

The decarbonization of power systems, while widely studied, seldom compares the cost implications of the underlying planning assumptions. For example, the time horizon that is considered, and the scope of regional cooperation, can have a significant impact on costs. To highlight the benefits of long-term, multi-stage, cooperative plans, we compare them with myopic and less-cooperative cases. The model is tuned to Northeastern North America, stylized as five regions in Canada and the United States. Generation, storage and transmission decisions are included, as well as investment cost and load growth uncertainties. Assuming optimization over three stages and regional cooperation in transmission, simply decarbonizing the system for 2050 under a stable load leads to a mild 70% increase over 2020 yearly costs. Tripling the load brings a 15-fold increase in costs. However, if optimization is performed myopically, one stage at a time, or if deployment of new transmission lines is prevented, tripling the load brings an approximate 17-fold increase over 2020 costs. If both myopic optimization is used and no new transmission lines are allowed, costs increase by a factor of 29.