Design and Valuation of High-Capacity HVDC Macrogrid Transmission for the Continental US

This work explores the benefits of increasing transmission capacity between the US Eastern and Western Interconnections under a high-renewables future. Given the existing “seam” between the two interconnections, a co-optimized infrastructure planning model was developed to assess trade-offs between investments in cross-seam HVDC transmission, AC and DC transmission needs within each interconnection, generation investment costs, and operational costs, at different renewable penetration levels. The model allows existing and candidate generation resources for deliverable planning reserves to be shared throughout the interconnections, a feature which drives identification of least-cost investments. This work is performed using an industry-vetted 169-bus representation of the North American power grid. Results from this analysis indicate that, under high wind/solar growth scenarios, the cost of a macrogrid HVDC transmission is outweighed by the generation-related savings they produce. The presence of other benefits related to grid reliability, resilience, and adaptability, suggest that cross-seam transmission is highly attractive infrastructure.