Maintaining grid reliability and stability is the core responsibility of Transmission System Operators (TSOs). The core problems to solve are intermittency and congestion issues, which have a direct impact on consumers. That is easier said than done, though. Most grid infrastructures around the world are aging. They are struggling to answer exploding demand due to the widespread electrification of devices and services, the adoption of electric cars, and the proliferation of data centers. Adapting to rapid evolution, these issues revolve around modernizing the grid, improving efficiency, and integrating power from renewable energy sources.
One key factor is optimizing load across the grid. Only through competent line capacity monitoring of each grid section in real time can power levels be automatically optimized where and when they are most needed. TSOs, though highly capable institutions, face both technical and financial obstacles in their quest to stabilize the grid.
Understanding TSO Challenges
On the technical side, the main culprits, intermittency and congestion, threaten the grid stability and, ultimately, consumers’ continuous access to power. On the money side, managing funds is complicated by ill-adapted regulations and the balkanized nature of the energy market.
Intermittency
Aside from the grid’s current structural shortcomings, the weather is a big contributor to power intermittency. Renewable power sources, though considerably less expensive than fossil fuel sources and less polluting, are asynchronous. Weather conditions directly affect their output, making it variable and unpredictable. Even fossil-source-produced energy is susceptible to transmission variations due to weather.
Wind and ambient temperature variations directly affect lines’ capacity. Rising temperatures heat the line, which creates energy loss and reduces its capacity. During heat waves, heat domes and stagnant air are particularly damaging as winds typically cool down the lines. There are notable exceptions to the wind’s cooling effect with hot winds such as the foehn or katabatic winds (like the Santa Ana winds in California) that hot, dry air down from higher altitudes. In winter, the problem morphs. Though colder weather does increase line capacity, it comes with its own set of troubles. When the temperature drops below freezing levels, lines ice down and snow up. The added weight creates sagging that can damage towers, poles, and insulators, or lead to galloping and its associated short-circuit risks.
Congestion
Even when power is abundantly available, the critical span, the transmission span with the lowest capacity in the grid section, defines the overall capacity of that section. Unless power is rerouted to bypass those limits, wide areas can be affected at the expense of the customers, not to mention the financial cost of these inefficiencies.
Congestion also stems from the current fractionalized state of the power grid. Renewable power sources are often located far from urban load centers and require transmitting large amounts of power they produce over long distances, which leads to ‘traffic jams’ on key transmission corridors. Maintaining fluid transmission prevents seeing wide-scale outages.
Paradoxically, the fact that this is a global issue is a good thing. Necessity is the mother of creativity, and local initiatives are testing imaginative techniques. Chile and Germany, for example, are working on integrating battery energy storage systems (BESS) into the power grid. Batteries absorb excess power during peak generation from renewables and release it when the demand rises. Battery storage, however, comes with a high deployment price tag. Hopefully, new technologies or economies of scale will reduce the costs in the near future.
Financial Challenges
Transitioning to renewables demands substantial grid investments and is complicated by slow, complex regulations. Often, slow, and complex regulatory frameworks are ill-adapted to the flexibility required to accommodate the situation on the ground. In the U.S., FERC Order 1000, for example, requires TSOs to participate in regional planning processes, which restricts their ability to make independent decisions about transmission expansion.
Market Maladaptation
TSOs have to work across a fragmented, decentralized market. FERC Order 2222, which aims to integrate distributed energy resources (DERs) into wholesale markets, may create computational burdens for TSOs in managing complex market participation rules. A recent U.S. Department of Energy (DOE) report, National Transmission Planning Study, provides some hope. It estimates that connecting scattered regional grids could augment interregional transmission capacity and yield significant long-term benefits that far outweigh the initial costs. During a webinar introducing the study, Maria Robinson, head of DOE’s Grid Deployment Office said that high-voltage and direct-current transmission lines linking regions could lead to substantial savings.
Potential Solutions
There are a few possible solutions available to mitigate the technical intermittency and congestion issue.
Intermittency
Addressing renewable intermittency requires accurate 72-hour weather forecasting. Predicting reduced solar output during rainy days or increased wind power during storms allows TSOs to plan energy rerouting effectively. Combining this with the interregional transmission capacity recommended by Robinson would further improve the efficient use of renewable energy sources.
Congestion
Precisely identifying the location of a recurrent critical span is, well, critical to preemptively reduce congestion Sometimes, reduced ampacity at a specific point is due to climatic factors. When the same points chronically show reduced capacity, it indicates that there is likely to be a technical problem at that point.
For example, insulators’ hydrophobic capabilities might have been damaged by pollution, soot from flying soot from a fire forest, or even bird droppings. This would cause repeated short circuits, weaken the line integrity, and potentially lead to heavier damage, known as partial discharge . If a transmission span line has been impacted and its capacity is permanently affected early detection enables a planned local outage to replace the damaged section and replace its damaged line with a better-performing one. This is far more efficient than waiting for the damage to get worse, strangling the ampacity of an entire section and making it less likely that it would withstand a severe weather incident.
However, this requires obtaining abundant and accurate data. Without actionable data, predictive analysis is impossible. With the right data, predictive analysis provides the accurate information needed to prioritize maintenance teams’ tasks and send them where their efforts have the maximum impact. Obtaining that data in real time and with the precise location of the transmission span generating punctual or recurrent alerts is crucial to enable predictive analytics. The optic fiber sensing technology is the ideal line data collection system. It turns a single strand of the existing Optical Ground Wire (OPGW) into a set of highly sensitive distributed sensors monitoring hundreds and thousands of kilometers or transmission lines.
Prisma Photonics is at the forefront of optic fiber sensing technology. PrismaPower’s machine learning algorithms use the detailed data collected on the grid to detect and classify events accurately and in real time, pinpointing them down to the precise tower locations. All the information and alerts are organized and streamed in real-time into one command and control center so PrismaPower can continue scaling with the grid.
Learn more about how Prisma Photonics can help TSOs improve powerline monitoring in 2025
