"Super Grids to the Rescue: Capturing Solar and Wind Energy to Combat Caribbean Hurricanes"

Researchers at Oak Ridge National Laboratory (ORNL) have developed a model to sustain electricity in the Caribbean during hurricanes by exploring "super grids." These interconnected grid systems aim to offset the impact of reduced solar power during storms, enhancing energy reliability and resilience.

When hurricanes threaten tropical shores, “super grids” could come to the rescue. Caribbean islands are shifting away from importing expensive fossil fuels, using their abundant sun and wind to generate electricity. However, frequent hurricanes can significantly reduce solar energy generation. ORNL researchers developed a comprehensive modeling method to better predict the drop in electricity generation when storm clouds overshadow solar panels. The team explored ways to compensate for these energy losses with super grids, a collection of interconnected grids allowing electricity to flow across island chains or between continents.

Lead researcher Rodney Itiki emphasized that this infrastructure planning is crucial for maintaining equitable access to electricity in the Caribbean’s 12 island countries and U.S. territories like Puerto Rico and the U.S. Virgin Islands. These historically underserved island residents cannot easily evacuate from the many hurricanes that hit the Caribbean each year. The loss of solar energy during hurricanes is likely to become increasingly important on islands like Puerto Rico, which aims to convert to all-renewable energy by 2050.

Itiki’s model can be used to understand the impact of hurricane clouds on any electric system. In this study, he and his team of experts in grid integration, renewables, and advanced computing methods used his algorithm to explore different grid connection approaches. They modeled how each approach would affect the availability of electricity, analyzing how a large hurricane would reduce power from known solar installations while traveling 10 possible paths over 10 to 14 days.

“This is one of the major contributions of the research, because when we design the power system, we need to do it considering all possible cases – most of all, the worst-case scenario,” said Itiki, a postdoctoral research associate with ORNL’s Power Systems Resilience group.

Researchers used simulations to understand power availability during hurricanes if electric grids were connected via high-voltage cables on the ocean floor. To learn whether these super grids would balance energy flow among regions, the team modeled four different combinations: a standalone U.S. grid; a standalone Caribbean super grid tying all the islands together; a U.S.-Caribbean super grid; and a super grid connecting the U.S., Caribbean islands, and South America.

The largest super grid configuration included 90 photovoltaic plants within the hurricane corridor, plus solar farms in places like California and Brazil that are unaffected by these hurricanes. The model showed some solar plants losing as much as 88% of their generating capacity for two days while shaded by hurricane clouds.

Researchers found the U.S.-Caribbean super grid increases power reliability the most. The standalone Caribbean super grid proved least helpful, partly because hurricane trajectories typically align with the chain of islands. The South American addition did not significantly reduce power variations because the continent has few solar installations. However, it could provide energy security as an alternate power supply if islands became disconnected from each other or from the U.S. system.

Itiki was intrigued as a graduate student by the successful subsea link between the electric grids of the United Kingdom and Germany. He studied the potential benefits of similar connections until a 2017 natural disaster narrowed his geographic focus.

“Soon after Hurricane Maria hit Puerto Rico, I started thinking about interconnecting Puerto Rico with Florida,” Itiki said. Maria left some Puerto Ricans without electricity for almost a year, the longest blackout in U.S. history.

Itiki’s initial focus was on wind energy during hurricanes. He explored how a U.S.-Caribbean super grid could reduce power slumps caused when hurricanes damage Puerto Rican wind turbines. After improvements to turbine technology made them stronger, he examined how a surge of hurricane wind energy could be shared among the Caribbean, the U.S., and South America.

Next, Itiki intends to combine his solar and wind algorithms to determine how super grids could broadly enhance energy reliability in both the Caribbean and the mainland. For example, during a major weather event in the U.S., could the Caribbean grid provide supplementary power to the U.S.?