How Utilities Make Sure We Have Electricity Access in Extreme Weather
Damages from natural disasters in 2017 alone cost $306 billion, the most expensive year on record. Flying debris and downed trees from high winds, coastal flooding, and fires in dry regions can cause significant damage to the U.S. electricity system. While utilities encounter different weather-related risks based on local and regional threats, several options are available to boost the resiliency of the power grid.
A resilient distribution system requires three things: prevention, recovery, and survivability. Prevention involves hardening the distribution system to limit damage. Recovery includes tools and techniques to restore service for customers. Survivability is the application of technologies to ensure customers have some level of normal electricity access when the grid is not completely operating. According to Chris Eisenbrey, Senior Director at the Edison Electric Institute, which represents investor owned utilities:
There is no one solution to hardening our energy grid or creating a more resilient system. Rather, electric companies and their regulators must look at the full menu of options and decide the most cost-effective measures to strengthen the grid and respond to storm damages and outages.
Southwire Company and Utility Dive Brand Studio recently surveyed over 100 industry executives and found that managing vegetation by trimming trees is the most common hardening task to prepare for storms. The second is upgrading transmission and distribution lines with modern cables that can withstand high winds, rain, and snow.
About a quarter of utility respondents are moving transmission and distribution lines underground. Doing so is very expensive, about five to 15 times more than overhead distribution. Illinois, New Jersey, and Virginia introduced measures in 2017 that would require the undergrounding of certain electrical lines for added resiliency.
Putting lines underground, however, is not 100 percent effective. Underground lines could complicate utilities’ efforts to respond to equipment problems because equipment may be destroyed after a storm or fire. Some devices such as network protectors are not designed to operate in extreme circumstances. Thus, troubleshooting and restoration may take longer for underground equipment since digging would be required to investigate problems.
Fortunately, smart grid technologies helped companies respond to major outages during Hurricanes Harvey and Irma. Smart meters, which are deployed in more than half of U.S. homes, helped companies identify where outages occurred.
Companies also used drones with high-resolution cameras, global positioning systems, and sensors to generate fast damage assessments. Before drones were an option, evaluations were done by customers calling in and then sending a patrol to visually verify damages and map them on a wall. Thus, drones save time and money as they can easily travel over blocked roads, enabling faster solutions.
Investments in storm-resilient infrastructure is also crucial. In 2005, Hurricane Wilma caused power outages to more than 3.2 million Florida Power & Light (FPL) customers. According ti Eisenbrey, Hurricane Wilma downed approximately 12,400 poles, affected 241 substations, and damaged almost 100 transmission structures.
Lessons learned from the 2004–2005 storm season motivated FPL to invest more than $3 billion to build a stronger and more resilient energy grid. For example, FPL deployed real-time flood monitors at 223 of its substations most susceptible to storm surge. These monitors provide a warning if a flood threat emerges and allows the company to shut down effected substations, mitigating damage to the grid and enabling the company to quickly activate substations after a storm.
The benefits of FPL’s investments were illustrated in the aftermath of Hurricane Irma last September. Even though the storm caused power outages to 4.4 million FPL customers, the largest outage in the company’s history, there were approximately 4,600 poles down largely due to trees and vegetation, Eisenbrey explained. FPL was able to restore service to approximately 2 million customers within the first 24 hours of the storm exiting its service territory. In less than one week, Eisenbrey noted that FPL restored power to about 98 percent of affected customers in about half the time compared to Hurricane Wilma in 2005.
Overhead distribution equipment can also be reinforced with guy wires or steel poles to increase strength and withstand high winds. This can be especially helpful for lines leading to population centers. Two to four reinforced lines leading to such centers would increase chances for electricity access to be available even during high winds. Hydrophobic coatings can also be applied to the transmission and distribution system to help get rid of precipitation, mitigate water damage on non-ceramic insulators, and help with ice removal.
Reliable bulk energy storage may also help utilities provide backup power to its customers. Batteries in electric vehicles could even be used to supply energy to a home during an outage. For instance, Nissan unveiled a system that allows its Leaf electric car to connect with a residential distribution panel and supply a home with electricity for about two days.
Since microgrids can operate off the grid, they can provide electricity to critical sites after a weather incident. Hawaiian Electric Co. built microgrids for Schofield Barrack Generating station and Honolulu International Airport Emergency Power Facility to ensure independent operation in an emergency.
The SPIDERS Phase III microgrid project is also deployed at Camp Smith in Oahu, a U.S. Marine Corps installation, to ensure its ability to operate if the main grid were compromised. Hawaii State Representative Cynthia Thielen hopes that microgrids will become more prominent in the state to prepare for devastating weather-related grid damages similar to the destruction caused by Hurricane Maria in Puerto Rico last September.
While it will take about a decade for Puerto Rico to complete its grid reconstruction efforts, microgrids on the island will increase resiliency and spur economic growth. German energy storage company Sonnen has pledged to build microgrids in Puerto Rico.
Nuclear power can also be used to fuel microgrids with onsite fuel for long periods of time. Companies such as BWX Technologies, Inc. (BWXT) have the unique capability to support the design, testing and manufacturing of Gen IV advanced reactors that can be used for this purpose.
When the talents of BWXT and NuScale’s efforts with small modular reactors (SMRs) are combined, advancements can be made with microgrid systems. In fact, Sandia National Laboratories and the Defense Science Board support the use of SMRs at military installations to alleviate grid reliability concerns.
There are several options for utilities to address prevention, recovery, and survivability of weather-related incidents. Since utilities face different geographical dangers, solutions will be tailored to their risk assessments. At the same time, utilities must be aware of new tools and technologies that could help them prevent and recover from weather-related damages and ensure survivability of the grid.
As Vice President of the Lexington Institute, Constance Douris manages the energy portfolio. She has published research and given speeches about smart grid data, cybersecurity of the electric grid and how electric vehicles are a grid resource. You can follow her on Twitter @CVDouris.