In late 2005, Hurricane Wilma hit Florida with wind speeds of 120 miles per hour. It was the state’s seventh hurricane to come ashore in 18 months, and left approximately six million people without power. More than half of those were Florida Power & Light customers, and at the time Manny Miranda, who is now a president at Next Level Energy, was working in FPL’s distribution operations team.
“It took us 18 days to restore; our customers were upset with us, our regulators were upset with us, our commissioners were upset with us,” said Miranda on a panel at the Power Resilience Forum in Houston last month. “So we had to change. “
So began the first phase of what started out as an ad hoc effort to fix what was broken — but has evolved into FPL’s full-territory infrastructure overhaul nearly 20 years later. It was years before utilities started talking about “resiliency” as a priority, Miranda said; in fact, the word didn’t exist as a part of FPL’s vocabulary when Wilma hit.
But nonetheless, the aftermath of Wilma was an opportunity to — as Miranda Ballentine, a senior advisor at the Ad Hoc Group and the panel’s moderator, put it — “never let disaster go to waste.”
FPL’s Storm Secure program was focused for its first decade on grid hardening. That included changing all transmission structures to steel and concrete, and installing a concrete pole every few regular ones to avoid a domino effect when the weather took down power lines, Miranda explained.
Those efforts paid off: “Fast forward to 2017, we get hit with [Hurricane] Irma,” Miranda said. “Here’s the beauty: zero transmission structures down, and we were able to restore [the parts of] our transmission grid that went out within 16 hours.”
This reactive approach characterized the early resiliency efforts of many utilities across the country: Storm hits, customers get angry, something needs to change. But as utilities face increasingly frequent extreme weather events, ranging from wildfires to winter storms, they are looking to act more proactively — both because of regulatory requirements and as a necessary adaptation measure to worsening extreme weather. And as utilities establish their own resilience plans, the early and more ad hoc efforts of utilities like FPL have become case studies for how they can avoid Wilmas of their own.
Undergrounding and covered conductoring
That said, Hurricane Irma did end up damaging a lot of FPL’s distribution infrastructure, largely due to fallen trees. So in 2018, FPL began undergrounding those lines via a Storm Secure Undergrounding pilot. A year later, Florida passed a law that made it easier for utilities to recover the costs of storm resilience, prompting FPL to turn the pilot into a permanent initiative.
The utility has now undergrounded over 2,000 miles of neighborhood lines and hopes to have them all underground within the next 25 years, according to Miranda.
Undergrounding power lines has become a common resiliency measure nationwide, for both storms and wildfires. It is one of the strategies Southern California Edison has invested in since the catastrophic California wildfires of 2017 and 2018 — which were triggered by downed PG&E power lines several hundred miles north of SCE’s territory — kickstarted aggressive investment in proactive resiliency.
As Pedro Pizarro, president and CEO of parent company Edison International, said at another PRF panel, in the aftermath of those fires, SCE changed its standard for idle lines. “We used to ground them at both ends, and now we ground them at a minimum of every two miles,” he said. “And we’ve increased the level of undergrounding in the communities that were most impacted.” Those high-priority communities are generally rural places with limited road access, where a fire would be an existential risk.
That said, even these proactive efforts haven’t prevented crisis; SCE acknowledged that its own downed power lines likely caused last year’s devastating Eaton Fire in the suburban community of Altadena, which killed 19 people.
Accordingly, there’s a sense of urgency especially in these fire-prone areas where the utility equipment itself imposes a risk. At PRF, Pizarro emphasized that undergrounding is both costly and time-consuming, which has led SCE to rely for the most part on covered conductoring instead, a grid-hardening technique where overhead power lines are wrapped in multiple layers of durable, insulating materials.
“A mile of standard bare distribution wire is probably [a little less than] $700,000 a mile; a mile of covered conductor is probably up to about $900,000 a mile; and a mile of undergrounding… could be anywhere from $1.5 million to $5 million or more,” Pizarro said. Via covering its conductors, SCE has managed to harden 90% of its system in just a few years, he added.
Beyond grid hardening
SCE has also been “aggressively applying [artificial intelligence] across the company,” Pizarro said. The utility has developed a tool, called Advanced Waveform Anomaly Recognition System, which uses AI to improve grid reliability.
“Think about your Apple Watch monitoring all sorts of different things in your body — your temperature, your heart rate — and then telling [you], ‘Hey, you might be about to have a heart attack,’” Pizarro said. “[AWARE] works by fusing information from multiple sensors across the distribution system and putting it through AI. It can help us predict when and where faults are going to occur… and locate where a fault has taken place.” The latter is generally a challenge for utilities, especially when faults are located underground.
For other utilities, extreme weather events have simply flagged a need to improve existing software. Julie Caruthers Parsley is the CEO of Pedernales Electric Cooperative, a distribution utility connected to ERCOT and covering a territory of about 8,100 square miles in Central Texas. When Winter Storm Uri caused widespread outages across ERCOT in 2021, “it pointed out all the weaknesses that we had,” she said at a panel focused on Texas.
“Our software that did the rolling failed,” Parsley said, describing how ERCOT instructed them to roll a third of their load with just 45 minutes of warning, and the programs failed. “We ended up having to manually roll — we had guys in the operation center flipping one feeder on and the other off.” Now, Parsley added, Pedernales has updated its systems so that they are able to handle that kind of stress.
For Pedernales, a second lesson came from Winter Storm Mara, a smaller storm that hit its coverage area head-on two years later. The storm caused nearly 100,000 outages and triggered pole collapses due to falling vegetation and ice loading. This damage was especially prevalent where power lines share poles with telecom lines, creating a thicker surface area for ice to accumulate.
“We’ve had to learn vegetation management…[and] we’ve had to really get after the telecom companies to try to make them do their vegetation management, because 75% of our poles broke at the communication line,” Parsley said.
Now, the utility uses LiDAR technology to handle its vegetation management, which Parsley says has saved them tens of millions of dollars, and has led to less than 5% of outages being linked to trees or branches falling. In the aftermath of the storms, the utility also started a pole test and treat program, which involves testing and replacing every pole within 10 years.
“On the whole,” she said, the storm “made us much more resilient.”
