Hurricane Maria Aftermath: Why Did Puerto Rico’s Electric Grid Fail?

Soldiers stationed at 783rd Maint. Co. in Toa Baja, Puerto Rico, provide support after Hurricane María hit the island.
(Alexis Velez/Puerto Rico National Guard)

Hurricane Maria, the latest storm to devastate the Caribbean, has been particularly destructive in the US Commonwealth of Puerto Rico. The island’s power has been completely knocked out, with some estimates saying it will be six months before the grid is fully restored. President Donald Trump is set to visit the island next week to get a first-hand look at the destruction.

CURENT—the Center for Ultra-Wide-Area Resilient Electric Energy Transmission Networks, housed in the University of Tennessee, Knoxville’s Tickle College of Engineering—recently had a conference in San Juan, where they met with officials from the Puerto Rico Electric Power Authority.

CURENT specializes in research related to the grid, electricity, and power use and storage.

Experts from CURENT can discuss some of the following issues related to power outages:

Why does power often go out in storms?

Power is often produced far away from areas that use it, meaning transmission lines are needed to get it to customers. Exposed lines are particularly vulnerable in storms, as are the towers and poles that support them.

Why is it hard to restore power after storms?

Because it often isn’t just that the lines need to be restrung but also that the supports for the lines, and perhaps even the generation plants themselves, need to be totally replaced.

Why not bury power lines?

While it might better protect against storms, burying power lines comes with a cost that some areas find prohibitive.

What kind of steps can be taken to design new systems that can be better maintained and repaired?

One idea is microgrids—systems that can operate independently of the overall power grid when the situation arises. They generate power by drawing on solar and energy storage and can operate in times when the main grid might be down.

How might microgrids help in situations like the current one in Puerto Rico?

If microgrids were deployed, they could rapidly be activated using stored energy. While far from returning power across the island, such usage would allow quick restoration to vital areas and services such as medical, law enforcement, and humanitarian facilities.

Are microgrids affordable and available?

One of the issues of establishing microgrids is their cost. While their initial startup is costly, their resilience and reliability can overcome that factor over time.

Could the US face a similarly dire situation?

One of the things that makes the problem worse in Puerto Rico is its location. While goods have to be flown or shipped to the island, the ability to use roads and rail in the mainland helps shorten repair time.

How does work being done at UT play into this situation?

CURENT is constantly testing, monitoring, and developing new ideas for grid performance. This work helps improve electric infrastructure, both in times of storms and in normal situations.

For more information, visit curent.utk.edu or call 865-974-9720.

CONTACT:

David Goddard (865-974-0683, david.goddard@utk.edu)