Strategic Rationale for the Interconnection of the Dominican Republic and Puerto Rico Electricity Markets Through HVDC: Positioning the Dominican Republic as a Regional Generation Hub

Island power systems are inherently characterized by high fuel import dependency, limited generation diversity, constrained economies of scale, and elevated vulnerability to extreme weather events, resulting in higher system costs and reduced operational resilience. This paper presents a technical and strategic assessment of a proposed high-voltage direct current (HVDC) submarine interconnection between the Dominican Republic (DR) and Puerto Rico (PR) across the Mona Passage. The study evaluates comparative system characteristics including installed capacity, peak demand, renewable penetration, infrastructure constraints, and long-term demand projections. While Puerto Rico operates a mature but spatially constrained grid with limited demand growth and aging infrastructure, the Dominican Republic exhibits sustained load growth, greater siting flexibility, and expanding generation capacity with increasing renewable integration. The analysis demonstrates that the net economic and reliability benefits of the interconnection are maximized when incremental firm and renewable-supporting generation is developed in the Dominican Republic and transmitted to Puerto Rico via a controllable HVDC link. The HVDC configuration enables asynchronous grid coupling, bidirectional dispatchable power exchange, improved stability margins, reserve sharing, and enhanced system adequacy. Results indicate that coordinated generation–transmission planning under this architecture reduces total system costs, supports higher renewable penetration, and strengthens resilience under extreme-event contingencies. The proposed DR–PR HVDC interconnection constitutes a technically feasible and economically justified platform for regional power system optimization and Caribbean electricity market integration.