Meeting Transmission Expansion Challenges Today

The Challenge

The International Energy Agency (IEA) estimates that global electricity demand will rise 25-30% by 2030 due to commercial electrification, EVs, heat pumps, and hydrogen. To meet the demands of an electrified future, the transmission grid has to triple in the next 10-20 years, with necessary investments exceeding $75 Billion a year. The current rate of transmission growth will not be able to support the projected growth in demand. The Brattle Group’s Building a Better Grid Report estimates that transmission needs to grow by 8,000 miles each year, however, the rate of transmission growth in the last year has declined. As a result, congestion is rising along with costs to consumers.

The speed and breadth of changes needed in the transmission system are significant, especially considering the challenges that transmission projects will face such as permitting delays, labor shortages, NIMBYism, material shortages, and consumer price protections in reaction to the inevitable rise in electricity rates due to capital expenditures. 

The Solution

It is clear that significant transmission expansion is necessary, but how do we get there? Leading experts suggest a three-pronged approach to quickly and safely expand transmission capacity. Here we’ll discuss how Dynamic Line Ratings and Advanced Transmission Monitoring are crucial components of each solution. 

chart, pie chart
Source: Johannes Pfeifenberger on Linkedin
1/3 of the needed transmission capacity additions will come from new greenfield transmission lines
1/3 of the needed additional capacity will come from upgrades to existing lines (such as converting aging existing AC lines to higher-voltage lines, using advanced conductors, and converting existing lines to HVDC that offers 2-3x the existing capacity without additional rights of way)
1/3 of the necessary additional capacity will come from advanced transmission technologies and innovative grid operations (power flow controls, dynamic line ratings, topology optimization, etc.) that increase by 30-40% the capability of both the existing grid and new greenfield transmission investments. (Johannes Pfeifenberger)
LineVision’s non-contact sensor platform delivers:

Dynamic line ratings (DLR) use field-monitored data and represent the true line rating — making no assumptions. They use sensors to collect real-time data about the conductor temperature, sag, and the contributing factors to conductor conditions; air temperature, solar radiation, and wind speed and direction on the transmission line. Armed with this crucial information grid operators can utilize the additional capacity to optimize system operations.

Situational Awareness Monitoring ensures lines are within safe operating limits with real-time alerting on threats to grid reliability or public safety. By monitoring the sag, blowout, and ambient weather conditions; utilities receive real-time alerts on anomalous movement/sag on lines, icing risk, and accumulation. 

Asset Health Monitoring utilizes digital twin models to understand conductor health and prioritize maintenance. This includes loss of strength from historical annealing analysis, conductor end-of-life projection, phase-by-phase observed sag distributions, observed sag/temperature relationship curves, conductor elongation analysis, projected safe maximum operating temperature, and rated breaking strength evaluation & aeolian vibration risk.

The Benefits of DLR and Advanced Transmission Monitoring:

For New Transmission, Existing Infrastructure, and Rebuilds/Reconductoring

Increasing Capacity, Reducing Congestion

DLR and Advanced Transmission Monitoring stand to have a significant and positive impact on the power grid, whether deployed on new transmission projects, existing infrastructure, or to support rebuilds and reconductoring. 

DLR's benefits are evident in a study of the ERCOT Grid, where it led to a 77% reduction in congestion costs and the integration of about 2.5 GW of renewable energy. A National Grid DLR project in New York is expected to decrease renewables curtailment by over 350 MW and enhance circuit transfer capacity by 190 MW, eliminating the need to rebuild 26 miles of transmission lines. This cost-effective project offers substantial savings compared to traditional line rebuilding.

Even on newly constructed transmission lines, DLR adds value by increasing capacity. According to the Building a Better Grid Report, “Previous analysis of the Southwest Power Pool (“SPP”) system has shown that GETs will increase the utilization level of existing 345 kV lines by 16%. GETs can also be deployed after the fact to mitigate unanticipated consequences triggered by the new line(s). For example, if energizing the new line(s) results in unintended congestion, such as those on the underlying lower voltage lines, GETs could be quickly deployed to address it. It's also adaptable post-construction to mitigate unexpected congestion triggered by new lines.” 

However, the most notable benefits of DLR are on existing infrastructure, providing up to 40% additional line capacity while enabling renewable integration, reducing congestion costs, and fortifying the grid. This augmented capacity empowers operators to manage power during planned and emergency outages without compromising reliability.

Situational Awareness

Whether old, new, or improved, transmission lines still are at risk of anomalous events and the accumulation of ice, meaning that left unmonitored, lines could fail, be damaged, or cause wildfires.

New transmission lines can still be affected by icing, anomalous movement, and other events that can pose a risk to power reliability and operations. By equipping new transmission with situational awareness monitoring, operators can stay alert to anomalous movement/sag on lines, icing risk, and accumulation.

It is important to monitor the live condition of conductors to alert them to anomalous movement/sag and icing. Asset health monitoring is essential for our transmission lines to ensure it is not degrading or likely to fail before expected and acting proactively when issues are found. 

Rebuilds/reconductoring upgrades share the same benefits from situational awareness and asset health as new greenfield transmission. 

Asset Health

Measuring the health of conductors ensures that new investments are protected and that existing infrastructure is not degrading or likely to fail before expected. 

By equipping new transmission with asset health monitoring, operators can ensure the reliability and protection of their investment. If temperature/sag distributions, annealing, or other indicators deviate from the norm, preventative measures can be taken before problems arise.

Brattle Group Building a Better Grid Report

In Conclusion

The Building a Better Grid Report best summarizes DLR’s complementary role to all stages of transmission expansion. “These technologies are highly complementary to transmission expansion through new lines. They can magnify the cost effectiveness and capabilities provided by new transmission investments. They provide short-term solutions to temporary operational challenges, such as during transmission outages or the construction of new lines, and bridge gaps until permanent expansion solutions can be put in place. They also are realistic alternatives for long-term solutions, particularly where building transmission makes less economic sense. GETs enhance transmission investments, rather than eliminating them, acting more as a tool to augment, akin to a GPS or tire air pressure sensor making driving easier—not by themselves replacing the car.

The needs for these technologies will only increase as the pace of the energy transition accelerates and necessitates doubling or even tripling of grid capacity over the next ten to 20 years. The pace and magnitude of this challenge requires an unprecedented effort and it is unlikely to succeed if transmission owners and planners only focus on the traditional transmission development approach. It is prudent to consider GETs—a complementary technology to transmission—as part of the solution for expanding future transmission.”