With destruction from Superstorm Sandy in mind, Florida Power & Light is shoring up 14 electrical substations in Miami-Dade and Broward counties and another 11 across South Florida that are vulnerable to damage from storm surge.
The monster storm sideswiped South Florida and, aside from chewing up a chunk of A1A in Fort Lauderdale, caused minimal damage here. But Sandy’s surge, which topped 14 feet in New York City, devastated power plants, sewage plants and other critical infrastructure along the coast in several Northeast states. That damage has proved an eye-opener for many coastal utilities.
Earlier this year, FPL launched a $500 million, three-year program to improve the storm resilience of power poles, substations and other parts of the grid. In 2006, FPL ordered up an initial storm-hardening program after widespread power pole failures during the 2004 and 2005 hurricane seasons, when repeated hurricanes struck South Florida.
The 25 substations in South Florida, most of them decades old, have not been flooded by surge in the past but new, more sophisticated modeling suggests they could be risk of damage under some storm scenarios, said Marty Mennes, an FPL project manager.
“Just because it hasn’t happened to us doesn’t mean it won’t happen,” said Mennes at a small substation in Fort Lauderdale undergoing the upgrades.
The substation is in an industrial area on the edge of Pond Apple Slough, a wetland preserve bordering the New River just west of Fort Lauderdale-Hollywood International Airport. Though the facility is several miles inland and west of I-95, it’s at risk because a major hurricane could potentially push water up and over the banks of the New River.
FPL spokesman Bill Orlove said computer scenarios produced by the National Hurricane Center show the substation, which serves about 4,000 customers, could potentially see a range of flooding impacts from hurricanes: eight-tenths of a foot from a Category 3 hurricane at high tide, 2.9 feet during a Cat 4 and as much as 5.2 feet during a Cat 5.
The upgrades focus on a small bunker-like building called the “relay vault.’’ It houses electronics and communication equipment that allow off-site operators to control banks of transformers that covert high-voltage power coming into the substations into lower-current juice sent out to homes and businesses.
A crew on Tuesday was installing a new surge-proof door built with thick gaskets and heavy locking bolts. It looked a bit like the watertight doors installed in ship bulkheads. Mennes said it was built to be twice as strong as hurricane doors installed in homes. New metal louvered windows also are designed to keep out water and wind.
It will be fitted with a sump pumps in the floor designed to keep any water that does get in from pooling and damaging equipment. The one to be installed at the Fort Lauderdale substation can pump up to 80 gallons a minute. The 24 other substations most at-risk in Miami-Dade, Broward, Lee, Collier, Charlotte and Sarasota counties will get similar systems.
Those substations are part of more than 200 that also will be equipped monitors on the outside walls to allow FPL to monitor rising water as it happens.
The protections won’t necessarily make the substations flood-proof, Mennes said, but they could help FPL keep them operating longer during a storm and get them back online faster after a hurricane.
Environmentalists, citing storm surge concerns and rising sea levels, have urged FPL not to pursue a separate plan to add two more nuclear reactors to the Turkey Point power plant along Biscayne Bay in southern Miami-Dade. FPL, while still awaiting regulatory approval, has defended the site, saying the new reactors will be built atop elevated mounds of fill.
Orlove said the substation improvements were intended specifically to address concerns raised by Sandy, not climate change and rising sea levels.