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How To Enhance Electric Power Grid Security

Updated: Dec 28, 2021

Every asset of the electric power grid, from open air substations to enclosed substations and overhead transmission lines, is vulnerable to attack. Of the 99 Reliability Standards published by NERC, one presents requirements for physical security and 15 present requirements for cyber security. There are no physical security standards for facilities that are operated at less than 200 KV. Despite these limited guidelines, electric utilities need to establish physical security standards for all facilities.


By enhancing physical security protecting critical grid infrastructure, electric utilities can decrease the vulnerability of their assets to damage incurred by vandals, saboteurs, or disgruntled employees. More importantly, electric utilities need to develop strategies that compare operational risks, financial considerations, and acceptable outcomes.


Physical security systems should eliminate the possibility that a saboteur can interrupt the flow of electric energy to:

  • More than 1,000,000 residences.

  • More than 100,000 residences for 24 hours or more.

  • More than 10,000 residences for 72 hours or more.

The analysis should include a list of scenarios, by location, that result in outcomes that exceed the above listed criteria.


The solution should include: an explanation of how proposed security systems affect the possibility of a saboteur interrupting the flow of electric energy to consumers, and the level of risk before and after the solution is implemented.


Prescient’s power system security risk assessments can inform utilities about the risk they face and prudent enhancements to reduce that risk. Although all electric utility assets need to be protected from attack, the level of protection needs to be appropriate for the risk to the neighborhood, the risk to the service area, and the risk to the electric utility. In this post, we’ll explore upgrades to security for a variety of critical grid infrastructure.


Open Air Substations


Open air substations are the most challenging to secure. Vandals could easily climb chain link fences topped with razor wire. Saboteurs could easily identify open air substations using Google Maps. Figure 1 is a satellite image of a transmission substation that shows vital components like transformers, circuit breakers, and control buildings, as well as roadways, inside the fence. Images like this can be downloaded for every open air substation in the United States. By zooming in, saboteurs can even identify the number of lines terminated at a substation and follow transmission lines to adjoining substations.

Figure 2 shows an open air substation with a surrounding embankment featuring a berm and vegetation. While placing an embankment around an open air substation beautifies the neighborhood by reducing visibility, and provides a barrier against vehicle intrusion, it does little else to improve physical security. In fact, an embankment increases susceptibility to small arms fire, as saboteurs could shoot into a substation from an elevated location along the berm.

The security of open air substations can be enhanced in many ways. A few examples include:

  • Converting aerial transmission and distribution lines to underground lines before lines are terminated in substations.

  • Placing barriers around critical components to prevent damage from small arms fire.

  • Reducing top of bushing heights to ten feet.

  • Reducing height of structures.

For a comprehensive overview of prudent enhancements to physical security at open air substations, contact us.


Enclosed Substations


Enclosed substations are less challenging to secure, so long as the entire substation is enclosed. Figure 3 is a satellite image of a partially enclosed substation that was built under a 345 KV overhead transmission line. Open-air piping in the area adjacent to the gas-insulated substation (GIS) building is SF6 transmission line taps to underground line terminations and overhead line dead end structures. Vandals and saboteurs can easily access this substation, leaving the open-air components particularly vulnerable to attack.

A few methods of enhancing security at enclosed substations include:

  • Converting aerial transmission and distribution lines to underground lines before lines are terminated in substations.

  • Placing vehicle intrusion barriers around the building.

  • Alerting security when one person is in the building, unaccompanied, for more than five minutes.

For a comprehensive overview of prudent enhancements to physical security at enclosed substations, contact us.


Overhead Transmission Lines


Securing overhead transmission lines is challenging. When multiple overhead transmission lines are located on the same right-of-way, as seen in figure 4, a saboteur could easily disrupt the flow of electric energy to a city or cities. At break angle structures, like the two shown in Figure 4, a saboteur could compromise the structure on the right so that it falls into the structure on the left. This could damage four 345 KV lines. According to the FBI’s Joint Terrorism Task Force, overhead transmission line structures have been the target of sabotage in the past.

To enhance the security of overhead transmission lines, try:

  • Providing adequate spacing between break angle structures, so that the distance between structures is equal to the height of the structure plus ten feet.

  • Limiting the amount of power than can be transferred across an energy transfer corridor.

For a comprehensive overview of prudent enhancements to physical security along overhead transmission lines, contact us.


Facility Monitoring: Match Homeland Security Threat Levels


Physical security protocols need to include provisions for monitoring that can be initiated by mirroring Homeland Security Threat Levels – green (low), blue (guarded), yellow (elevated), orange (high) and red (severe).


During low threat levels, remote monitoring of activities inside substations is sufficient. During guarded threat levels, remote monitoring of activities inside substations should be supplemented with random security patrols.


During elevated threat levels, remote monitoring of activities inside substations should be supplemented with remote monitoring of activities in areas adjacent to the substation.


During high threat levels, remote monitoring of activities inside substations should be supplemented with remote monitoring of activities in areas adjacent to the substation and with random security patrols.


During severe threat levels, remote monitoring of activities inside substations should be supplemented with remote monitoring of activities in areas adjacent to the substation and supplemented by onsite security staffing.


Physical Security at All Facilities Must Be Enhanced


All electric power grid facilities, including those critical grid assets explored in this blog, as well as neighborhood substations and critical transmission substations, must enhance physical security to reduce vulnerability to attack. All facilities should be equipped with access monitoring (both entering and exiting), intrusion detection, video monitoring, and more.


To learn more about the vulnerabilities within your power grid infrastructure, schedule a power system security assessment with Prescient. After an assessment, we will provide you with a report outlining prudent updates to physical security that will reduce your infrastructure’s vulnerability to attack. Or, if you’d like to dive further into the topic of physical security, contact us. We’d love to talk security with you.

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