By Ed Burke, Dennis K. Burke Inc.
We’ve all seen the news coverage of the devastating 2017 and 2018 hurricanes slamming into our coasts. We’ve had five major U.S. hurricanes over the past two years, and they’re certainly bigger, more intense, and more destructive.
These extreme weather events present tough resiliency challenges for the electricity industry. Work needs to be done to harden the grid.
Climate experts agree that resilience is becoming much more important to year-round utility planning and operations. It puts utilities under pressure to develop effective strategies that get residents on with their lives and businesses back to work.
Why Build Resilience?
It’s generally agreed that extreme weather events will be more severe as the planet warms. A 2016 Department of Energy report prepared by members of six national labs warns that: “Climate change poses long-term challenges by changing the frequency, intensity, and duration of the weather events that represent the largest source of disruptions to the US electricity grid.”
The report talks about the concept of resilience by addressing risk management:
- Robustness – The ability to absorb shocks and continue operation.
- Resourcefulness – The ability to skillfully manage a crisis as it unfolds.
- Rapid recovery – The ability to get services back as quickly as possible.
- Adaptability – The ability to incorporate lessons learned from past events to improve resilience.
There is an emphasis in the report on learning from experience so that the system becomes more robust over time.
To get ahead of storms and prepare communities for fast recovery in the most effective way possible, investment must be made early in infrastructure.
A single strategy or improvement won’t make your grid more resilient — it’s combining several improvements together to make it work. Utilities say it’s a holistic approach, building on a range of technologies and grid-management practices.
What Does Resilience Look Like?
Let’s start with a smart grid. A smart grid is an electrical grid that includes a variety of operational and energy measures, including smart meters, smart appliances, renewable energy resources, and energy efficient resources. Smart grid technology can automatically detect, isolate and reroute power when a problem occurs. This helps reduce the number of outages, decrease the duration of outages and can even help restore power in a matter of minutes.
Most extreme weather outages come from transmission and distribution problems, not generation issues. It’s the poles and wires that need to be fixed. Transmission and distribution networks are vulnerable to storm damage and will benefit from hardening measures. Undergrounding wire is expensive, but can substantially increase system reliability and resilience to extreme weather.
Resilience looks a little different. A microgrid is a localized group of electricity sources and loads (usually solar and batteries) that normally operate connected to the grid, but can also decouple to “island mode” to power critical infrastructure in emergencies.
Microgrids take advantage of wind, solar and batteries to harden a system, because they’re modular energy sources and can supply power from shorter distances, with less reliance on wires. Solar and wind also don’t rely on access to fuel and can often generate power immediately after a storm, providing resilience that other electricity sources do not.
We can now look back over two major hurricane seasons and judge how effective the grids’ resiliency strategies played out through these extreme storms.
Hurricane Irma was a vast storm impacting 27,000 square miles of the Florida Power & Light (FPL) service area. “While this is the worst storm our company has faced,” says Eric Silagy, FPL’s president and CEO, “rest assured we were ready, having pre-positioned the largest restoration workforce not just in our company’s history but in U.S. history.” At the height of the restoration work, FPL had 24,000 personnel involved, including 11,000 of its own employees and 13,000 workers from contracting companies and utilities across the nation and even Canada.
The success of FPL’s disaster recovery strategy grew from the experience it gained following Hurricane Wilma in 2005. FLP has since invested nearly $3 billion in making its energy systems “smarter, stronger, and more storm-resilient.”
FPL hardened more than 700 main power lines that serve critical facilities and services. It also cleared 150,000 miles of power lines of vegetation that could cause power outages; established a plan to inspect, upgrade and replace the company’s power poles; and installed nearly 5 million smart meters and 66,000 intelligent devices to deal with power outages when they happen.
In advance of Hurricane Irma’s approach, FPL took the precaution of shutting down its two nuclear power plants. The utility also planned to power down some of natural gas plants in the path of the storm to mitigate damage and enable FPL to bring sites online faster after the storm.
About 4.4 million people lost power as a result of Hurricane Irma, but within 16 days of its landfall, FPL was able to restore power to all of them, with only a few exceptions.
Hurricane Harvey was the most powerful weather system to impact Texas and Louisiana since Hurricane Katrina. It left around a 250,000 customers without power. Despite catastrophic flooding, most had their power restored within days.
In Puerto Rico after Hurricane Maria, federal recovery arrived at a painfully slow pace. Private companies stepped up and deployed storage systems and solar arrays. Rapid recovery is something private companies tend to do much better than governments.
When Hurricane Florence parked over Duke Energy’s service territory, the utility leveraged improvements in mobile communications and data analysis for remote switching to reconnect their customers quickly.
Duke has a “Smart-Thinking Grid” plan that aims to reduce customers impacted by outages by up to 75 percent. According to the utility, portions of the plan already in place helped avoid over 80,000 extended outages during Florence.
In advance of that storm, Duke shut down one nuclear plant to protect it from high winds. Unfortunately, there were nine Duke substations that flooded during the storm. The wind farms in North Carolina escaped the highest winds of the hurricane and continued producing electricity throughout the storm.
After Florence passed, Duke reported that most of its solar came online quickly, although four of its utility-owned facilities remained offline for weeks afterward. Only one was because of damage, and the other three remained offline due to substation interconnection issues.
Considering the high winds in recent storms, solar systems fared relatively well, but the industry has highlighted a few potential improvements it would like to make.
Duke is investing in battery technologies and research to store energy from a diversified energy mix and dispatch clean energy where it’s needed. The utility is also considering microgrids as a solution to avoid building transmission and distribution lines in certain areas. The utility experienced over 1 million outages in North and South Carolina.
Just weeks later, Hurricane Michael became the strongest hurricane on record to hit the Florida panhandle. Outages from Michael impacted over 1 million customers in the Carolinas, and over 75,000 in Florida.
Finding the Political Will
Resilience has become a big concern among policymakers, but it is largely overshadowed by the president’s position on climate change. Many local and state governments have taken active steps to tackle their resiliency issues on their own.