Houston — As the Atlantic's ninth tropical disturbance threatens to become a tropical cyclone affecting the Bahamas and Florida, the Rocky Mountain Institute is working with Bahamian power utilities to enhance resiliency after Hurricane Dorian's devastating effect on those islands' mainly diesel-driven power grids.
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A tropical depression that the National Hurricane Center forecast to become Tropical Storm Humberto on Friday had maximum sustained winds of 30 mph and was centered about 240 miles southeast of Grand Bahama and less than 200 miles southeast of Great Abaco Island -- both devastated by Hurricane Dorian's Category 5 winds on September 2-3.
The northwestern Bahamas faced a tropical storm warning, and much of Florida's Atlantic coast faced a tropical storm watch.
"On the forecast track, the system is anticipated to move across the central and northwestern Bahamas tonight, and along or near the east coast of Florida Saturday and Saturday night," the National Hurricane Center said.
Florida Power & Light spokesman Peter Robbins said Friday FPL is "definitely taking this one seriously and keeping an eye on it."
As the storm's path becomes clearer, FPL will position resources "as best we can" to respond quickly and safely, Robbins said.
After Hurricane Wilma devastated Florida in October 2005, FPL has worked to harden the grid and expedite service restoration, most recently by installing more underground power lines, Robbins said.
Duke Energy Progress spokeswoman Ana Gibbs, said her Florida utility's meteorologists "are closely monitoring the storm" and following its detailed storm response plan, which includes checking equipment and supplies.
Duke Energy's investments to harden its power delivery system "include inspecting and replacing equipment, trimming trees, replacing wood transmission structures with steel or concrete and installing grid automation and self-healing devices which help improve service reliability and reduce both the length and number of outages."
HARDENING AND RESTORING
On Friday, the Rocky Mountain Institute conducted a webinar about how to help restore the Bahamas power system so it can more effectively withstand and recover from the destruction wrought by Category 5 hurricanes such as Dorian.
Government-owned Bahama Power and Light serves all of the Bahamas except Grand Bahama Island, which is served by Emera's Grand Bahama Power Company. BPL has a maximum capacity of about 438 MW, and GBPC's gross capacity is 98 MW, according to their websites.
Grand Bahama and BPL's Abaco Island lost all electricity service during the storm, which is expected to take at least two weeks to restore, Rocky Mountain Institute spokesman Nick Steel said. Grand Bahama has about 18,800 customers, and Abaco has about 9,000.
"On Abaco, 90% of the infrastructure was completely destroyed," said David Locke, RMI senior director of empowering clean economies, during the webinar. "On Grand Bahama, the generating capacity is largely intact."
Current efforts to restore service focus on debris removal, Steel said, and "will be slowed by the rain and weather, but crews will work through the weekend," despite this new storm's approach.
Diesel generators provide most of the Bahamas' power, but BPL has a small-scale renewable generation program, and GBPC has a renewable energy rider program through which residential customers can sell excess energy back to the utility.
Rocky Mountain Institute learned from the destruction wrought by 2017's hurricanes Irma and Maria on Barbuda, Dominica, Puerto Rico and the Virgin Islands that much of the human cost of these storms was not from the wind and rain, but from the lack of power to provide essential health and safety services afterward, Locke said.
These islands had adopted grid systems with centralized generators and transmission and distribution systems, "which are inherently vulnerable to hurricane environments," Locke said.
RETHINKING HOW THINGS ARE DONE
David Gumbs, another webinar speaker who was CEO of the Anguilla Electric Company when Irma hit in September 2017, said, "We had to rethink the way we did things previously."
Since then, RMI has helped several islands through the Caribbean Electric Services Corporation, an association of power services and other stakeholders, to reorganize their systems with more "distributed generation, coupled with renewables that are not as reliant on outside" support, Locke said.
Part of that effort was the composition of the "Solar Under Storm" white paper, which describes best practices for ground-mounted photovoltaic solar systems so as to minimize damage and restore service quickly, Locke said.
A 1-MW car park solar canopy in the Bahamas withstood Dorian and continued to provide power, although disconnected from the grid, Locke said.
RMI is developing specifications and raising funds for a plan to build such systems, with diesel backup, to decentralize the Bahamas' power grid, so that essential services can continue when another major storm hits.
The plan should be designed to provide power "at lower cost and that is more resilient," Locke said, adding that RMI and local utilities hope to "use this as an opportunity to leapfrog into the 21st Century grid."
-- Mark Watson, firstname.lastname@example.org
-- Edited by Gail Roberts, email@example.com