Submarine Cable to Link Electricity from DR to PR, Revives Talk of USVI Link

M.A. Dworkin

San Juan, PR - The U.S. Department of Energy (USDOE) has approved a $2.5 billion project to build a 150km, 700 MW HVDC submarine cable that will link the Dominican Republic to Puerto Rico, allowing Puerto Rico to import electricity from a new Dominican natural gas plant. 

The project, which recently received a Presidential permit from the U.S. Department of Energy, is expected to start construction in 2027 and be completed in 2031. It will integrate both the DR and PR grids, improve regional energy security, and assist in transitioning from aging fossil-fuel-reliant infrastructure in Puerto Rico. It will be the Caribbean’s first cross-border energy connection. 

Known as the Hostos Project, the interconnection is designed for a capacity of up to 700-750 MW, capable of providing enough electricity to power roughly 600,000 homes or more than one-third of Puerto Rico’s residential energy needs. The infrastructure includes a 90-kilometer overhead line in the DR, a 150-kilometer undersea cable across the Mona Passage, and a 6-kilometer cable to the Mayaguez substation in Puerto Rico. The originating generation station in the DR will send power through three separate power lines from the plant to the coast where it will be transported via a submarine cable stretching across the Mona Passage waterway that links the DR and PR. 

The link will provide bi-directional capabilities to ensure stable power to both countries and allow for higher integration of renewable energy. Key benefits of the project include reduced operational costs for electricity generation, improved reliability, and reduced risk of power outages in Puerto Rico.

The PR grid is characterized by high vulnerability to storms, aging infrastructure, and high energy costs, and is still facing issues and outages years after the 2017 Hurricane Maria storm devastated a good deal of the island’s electrical grid. 

The Dominican Republic grid has been expanding its energy mix and is seeking to act as a regional hub, with capacity to export power. 

DR-PR-USVI Link

The USDOE’s approval and subsequent starting date for the Hostos Project has revived serious talk (which for some reason was buried 15 years ago) that involved stretching a submarine electrical link to the U.S. Virgin Islands from Puerto Rico. In today’s version, the link would originate from the Dominican Republic and travel through Puerto Rico to the USVI, bringing added electricity and stability to the Virgin Islands electrical infrastructure system. 

The technical and economical feasibility of submarine cables in recent years makes such a link all the more possible in 2026. It would provide significant cost saving for residential customers and provide a great deal more stability in electrical delivery.

For practical engineering reasons and cost factors, the USVI cables, which would be installed in phases, would originate in the DR and then start with the Fajardo substation in Puerto Rico and connect to the Krum Bay substation on St. Thomas. Instead of running directly from St. Thomas to St. Croix, where the waters reach depths of 7,200 feet, which is far deeper than submarine cables have so far been constructed, the latest studies on such a link showed that a 100 MW DC cable running between the Yabucoa Substation in Puerto Rico and the Frederiksted substation on St. Croix would be much more feasible with existing technology. 

Taking the idea a step further, the establishment of a Caribbean power grid would allow use of renewable energy from other islands such as Nevis, which is working on a geothermal power system that taps energy from volcanic heat. With the Caribbean’s abundant natural resources - from sunshine to wind to geothermal and hydro - the Caribbean is well positioned to lead one of the world’s most meaningful clean energy transformations away from fossil fuels to renewables. 

For the USVI, the link between DR-PR-USVI would offer much needed relief in energy costs to residents and a much more reliable electrical system without the worry of outages and hurricanes destroying great parts of the antiquated energy infrastructure.