As the electric grid evolves to meet the demands of a modern, digital society, the need for advanced monitoring and protection mechanisms has increased. The current grid is rapidly aging, susceptible to extreme weather, and struggling to adapt quickly to new sources of energy. Additionally, security threats to the grid are rising, and existing protection systems remain insufficient to address these dangers. The nation’s energy grid and transmission infrastructure urgently require expansion and modernization. Residential electricity consumption has increased by more than 20 percent since 2000, despite significant improvements in efficiency.
Building on a recent research report and policy brief, this post explores how Distributed Fiber Optic Sensing (DFOS) can be utilized to protect and monitor a modernized energy grid in real time to enhance security, reliability, and efficiency.
DFOS is a technology-based application that uses existing fiber optic cables as continuous sensors, capable of detecting and pinpointing changes in the environment. Regular fiber optics for telecommunications uses light signals sent through a fiber made from silica to send and receive huge amounts of data at nearly the speed of light. In DFOS, fibers measure the backscattering or reflectance of light to identify variations in temperature, strain, or vibration.
Fiber optic sensors have been demonstrated as effective in dozens of applications, including pipeline monitoring, earthquake detection, border security, structural health monitoring, and more. Distributed fiber optic sensing takes this one step further by utilizing even a single existing unused dark fiber within a bundle as a sensor. Often fiber optic cables are placed along utility corridors, making them ideal places to monitor other utilities and areas to protect.
DFOS systems can identify and localize anomalies with high precision, often within a few meters over distances well-exceeding 50 miles. This continuous monitoring contrasts with traditional point sensors, providing a more comprehensive view of utilities and areas. Fiber optic cables are often already installed underground in utility corridors or on utility poles often co-located with electrical infrastructure. DFOS is already showing promise in several key applications for electric grid monitoring and protection, including:
Dynamic Line Rating (DLR):
DFOS enables real-time thermal monitoring of electrical transmission lines. Dynamic Line Rating is the rating change of a transmission line based on local conditions rather than static assumptions, and provides extra capacity. Fiber optic technology is currently being piloted for DLR measuring. As it is immune to electro-magnetic interference, fiber optics are already often installed alongside some transmission lines, and would be a convenient and accurate measurement tool for line rating.
Fault Detection:
Fiber optics installed alongside transmission or distribution lines can detect faults through acoustic and strain measurements. Quick detection of faults can improve response times and help operators quickly take action to avoid accidents and minimize outages.
Asset Integrity Monitoring:
DFOS provides continuous surveillance of critical assets like transformers, substations, and underground cables. Monitoring temperature, strain, and vibrations can detect potential failures or threats. For underground electrical lines, DFOS can detect vibrations from heavy machinery, and can alert One-Call centers and utility operators of potentially unauthorized excavations that could damage utilities.
Physical Security:
Beyond operational monitoring, DFOS can also enhance physical security by detecting unauthorized movement near critical infrastructure. The technology has already been tested as border security, and can detect and differentiate between individuals, vehicles, and even tunneling.
DFOS has numerous advantages over traditional electricity security or monitoring systems. A single fiber optic sensor is continuous, meaning that it can precisely measure disruptions with high spatial resolution across significant distances. Instead of requiring hundreds of sensors spread across an area, fiber optics can provide complete coverage for temperature, strain, and vibrations. DFOS systems rely on an interrogator, which is an external unit that classifies light reflections, and do not require any additional power sources or sensors along the length of the cable. They are immune to electromagnetic disturbances and can be reliably operated in high-voltage environments. The biggest advantage from DFOS is that it requires no additional infrastructure. Many fiber optic cables are already located ideally to monitor underground and above-ground electricity infrastructure.
While DFOS offers numerous benefits, implementing the technology for grid security and monitoring will require careful planning and considerations. Fiber optic sensors will need to be integrated into Supervisory Control and Data Acquisition (SCADA) systems currently in place for electric grids. The continuous data stream from DFOS will also necessitate advanced algorithms and storage to handle effectively.
The greatest strength of DFOS may also be considered a weakness to overcome. While DFOS requires no additional infrastructure to implement and utilize, this advantage only extends to areas where fiber optic cables are already in place. Many transmission and distribution lines are located alongside fiber, but many of them are not. Fiber is most heavily concentrated in urban areas, meaning that extending DFOS capabilities across the entire electrical grid would require substantial investment. As a result, DFOS is a highly effective but selective solution, well suited for some locations and currently impractical in others.
Distributed Fiber Optic Sensing stands at the forefront of modernizing electric grid monitoring and protection. Its ability to provide real-time, high-resolution insights across vast infrastructure networks positions it as a vital tool in building a resilient, efficient, and secure energy future. Policymakers and industry stakeholders should support research and development efforts for DFOS and explore opportunities to expand its use across the energy sector. Embracing this technology not only enhances operational capabilities but also helps modernize and promote innovation in the energy sector.
Written by Owen Rogers, Public Policy Associate
The Alliance for Innovation and Infrastructure (Aii) is an independent, national research and educational organization working to advance innovation across industry and public policy. The only nationwide public policy think tank dedicated to infrastructure, Aii explores the intersection of economics, law, and public policy in the areas of climate, damage prevention, eminent domain, energy, infrastructure, innovation, technology, and transportation.