by Bob Burns, Haverfield Aviation
Power transmission lines are vulnerable to natural disasters such as extreme weather, wildfires and even earthquakes. Utilities are in the business of selling electricity, which they cannot sell if there is an interruption in the transmission system.
Storms that result in lightning, ice, snow and high winds or fire cause 70 percent of the damage that interrupts service. Damage to transmission lines frequently results in major power outages. Cost estimates from storm-related outages to the economy are between $20 billion and $55 billion annually, according to a 2012 report, “Weather-Related Power Outages and Electric System Resiliency.” Data also suggests weather-related outages are increasing.
Superstorm Sandy left more than 8.1 million U.S. homes without power. After such an event, the priority is restoring power to parts of the system that were damaged and that left customers without power. Typically, the easiest fixes are repairing distribution lines and bringing damaged power plants back online. When transmission lines are damaged, however, there rarely are easy fixes. Seriously damaged transmission lines can leave many customers without service for days or weeks.
It has been estimated that 90 percent of outages are from damage that affects distribution systems, but the remaining 10 percent are caused by damage to transmission lines. These are the problems that cause wider-scale outages and affect more customers, according to that same 2012 report. Between 1992 and 2010, some 78 percent of the reported 1,333 electric grid disruptions were weather-related and affected 178 million customers, according to a 2012 Lawrence Berkeley National Laboratory report.
Predictions are that with climate change, major storm activity will increase. Before robust disaster recovery scenarios can be reviewed and dependable plans for the power grid upgrade can be scoped, utilities need a detailed inventory of their transmission lines and hardware. Unfortunately, few if any have this information. Many lines, especially those spread over hundreds of miles in remote areas, have not been inspected for 30 or 40 years.
An above-average hurricane season expected this year made storm recovery planning even more critical. Researchers at Colorado State University predicted as many as 18 named storms during the 2013 season, compared with the 30-year average of 12. In addition, these researchers predicted a 72 percent chance of at least one Category 3 or higher hurricane’s making landfall on the U.S. coastline this year, an increase of 30 percent probability from 2012.
The Perception of Reliability
Contrary to the perception that the U.S. has one of the most reliable electric power systems, a statistical comparison shows the U.S. grid does not meet expectations. Figure 1 shows the U.S. has the highest average annual outage time per customer and the third-highest average annual number of supply outages per customer.
The overall condition of the electric grid prompts the American Society of Civil Engineers (ASCE) to refer to it as “a patchwork system” that requires a massive investment to avoid a catastrophic breakdown. The ASCE estimates that expenditures of $673 billion are required by 2020. In addition, the group estimates a gap exists between what is considered necessary and the current annual expenditures of $12.3 billion for power generation, $37.3 billion for transmission systems and $57.4 billion for distribution systems.
Preparing for Outages, Storm Recovery
The number of observed outages from weather-related incidents seems to be increasing. The reasons for more outages might be a combination of power grid deterioration and an increase in the number of observed extreme weather events. Improving the overall condition of the power grid makes it more resilient to natural disasters and facilitates faster recoveries from outages while it reduces the magnitude of the outages and the related costs.
Any proposed solutions for storm planning or grid upgrading that focus only on piecemeal fixes will miss the mark and potentially waste millions of dollars. The larger, systemwide risks must be identified so resources can be allocated most efficiently. Unfortunately, assessing the transmission system is difficult for the power utility industry.
Planning and preparation are crucial to effective storm recovery. Proactive planning and preparation is preferable to reactive actions. Three components are required in developing an effective plan:
- Dependable assessment of inventory (transmission lines, towers and hardware);
- In-depth review of the inventory data to identify and rate risk; and
- Formulating a comprehensive response plan based on the assessments of inventory and risk.
Few if any utilities have a full stock of existing inventory. Much of the physical grid dates back several decades–more than the average life span of the equipment.
The industry has not yet embraced the type of forward-thinking risk management planning that can minimize failure risk and optimize expenditures.
Some utilities, such as Con Edison, are developing proactive plans, including beefing up power grid surveillance.
Comprehensive inspections can be a part of that plan and can be completed quickly and economically through aerial investigations.
Using Emerging Technologies
Considering the continuing emergence of enterprise technologies and the seemingly endless uses throughout every business activity, it is natural to apply these technologies when inventorying and assessing transmission systems.
One helpful technology is VUEWorks software, an affordable geographic information system (GIS)-centric, Web-enabled, enterprise asset management solution designed for utility use. The software provides breakthrough inventory assessment capabilities for use in planning for disaster recovery, power grid upgrades and routine maintenance.
If a customer chooses, an inspection can take place with the simultaneous use of VUEWorks. The development of VUEWorks was completed through the marriage of software with a voluminous amount of data that had been collected by Haverfield Aviation.
VUEWorks integrates with GIS data, allowing users to share geospatial and nonspatial data on physical assets. Users can see risk areas on a map. This visual portion of the software solution is a major differentiator. The ability to display exhaustive data captured in the field during aerial inspections is a huge advantage to the industry. Most inspections report issues at a structure or span level. VUEWorks can track data at the structure, span, circuit and network level to provide a comprehensive view of the reliability of a utility’s power grid.
With a dependable assessment of inventory, an in-depth review of the data can identify and rate risk, allowing the development of a comprehensive response plan.
As it has been said, “You can’t stop storms, but you can respond more quickly if you know where the trouble spots are.”
Did You Know?
- 500,000 people per day in the U.S. lose power for at least two hours?
- On average, some 54 power outages each year affect more than 50,000 people?
- Outages cost between $80 billion and $188 billion annually?
- U.S. power grid outages average 92 minutes in the Midwest each year?
- The Northeast experiences total outages that average 214 minutes each year?
- 70 percent of power outages in the U.S. are caused by weather?
Bob Burns is vice president of sales and marketing at Haverfield Aviation. He has more than 30 years of sales experience, and while in the U.S. Navy, his duties involved support of jet aircraft and helicopter flight operations. Reach him at email@example.com.