A hurricane-proof Caribbean super grid

Modelling has been developed to estimate the impacts of shading on PV output during hurricanes and how a US-Caribbean-South America super grid could minimise these.

Solar PV is proving the most cost-effective option for scaling renewables in the Caribbean, as it is elsewhere. But it also is highly sensitive to shading and thus weather events such as the hurricanes that are prevalent in the region and that nucleate massive amounts of clouds around their centres to shade hundreds of kilometres in their paths.

The modelling tool from the US Oak Ridge National Laboratory (ORNL) was developed to improve predictions of PV power variability during hurricanes and other lesser tropical storms, enabling utilities to plan accordingly.

The researchers also assessed the potential of interconnecting the islands with HV submarine cables and connecting them to the continental US and South America in the form of a ‘super grid’ to share power in order to reduce the impact of the shading.

Have you read?
Caribbean advances renewables potential
Extreme weather pushes power grids to the brink – Is AI the answer?

With a range of 10 potential hurricane trajectories tested a standalone Caribbean super grid, including the US territories of Puerto Rico and the US Virgin Islands, was found to endure the most significant power valley among all the schemes.

This is primarily due to the close alignment of the islands so that they are nearly entirely covered by the shading caused by hurricanes and that the hurricane paths typically align with the island chain (the standalone grid modelled excludes the smaller southern islands).

A US–Caribbean super grid with an interconnection to Florida was found to significantly reduce the power variability during hurricanes passing over the Caribbean from almost 38% to less than 9%.

However, connecting South America to the US-Caribbean super grid via the southern Caribbean islands to the Guyanas and beyond was not found to significantly reduce the variability further.

Such an interconnection would add approximately 61GW of PV capacity, primarily from Brazil, situated outside the hurricane corridor and thus would provide energy security by an alternative power supply in the event of the disconnection of a segment of the Caribbean super grid.

“Reducing intermittent renewable power variability is critical in the transition to the decarbonisation of the power sector because power consumers expect high levels of service without power interruptions,” the researchers write in their paper in the journal Energies.

“This research demonstrates that the US–Caribbean–South America super grid or US–Caribbean super grid are alternative solutions to address the power variability in PV power plants under hurricanes.”