2024.10 EJ GETs

Dynamic line ratings (DLR)

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A transmission line’s capacity is not constant. When air temperatures are cool, for instance, a transmission line has greater carrying capacity than when higher temperatures risk overheating lines. Wind speed, solar radiation, and the condition of a line also affect its capacity. These conditions not only change frequently, but they are also location specific. DLR utilizes both real-time monitoring and prediction of local weather conditions to continuously optimize its capacity. DLR’s localized, real-time approach is a fundamentally different to assessing transmission line capacity than more traditional approaches, like static ratings. Static ratings assume worst-case environmental conditions to ensure lines operate safely under any scenario, even if it means significantly reducing capacity much of the time. Ambient Adjusted Ratings (AAR) utilize prediction of ambient temperature to determine ratings. DLR utilizes both predictions and measurement of wind, solar and radiation as well as ambient temperature.

Dynamic Line Ratings (DLR)

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Advanced Conductors

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Advanced Power Flow Control (APFC)

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Transmission Topology Optimization (TTO)

Traditional conductors are made using aluminum that is wrapped around a strong steel core that can be operated at relatively low temperatures of under 100oC. In recent years, however, conductor manufacturers have begun making conductors using both aluminum and steel, as well as using newer materials such as carbon or ceramic composites that can operate at higher temperatures. The DOE’s Advanced Materials and Manufacturing Technologies Office (AMMTO) even launched a contest called the Conductivity-enhanced materials for Affordable, Breakthrough Leapfrog Electric and thermal applications (CABLE) Conductor Manufacturing Prize to spur innovation. Reconductoring existing transmission lines or building new transmission lines with advanced conductors can in certain cases have a big impact. For instance, when short-distance AC lines are thermally limited by a conductor, advanced conductors can increase current-carrying capacity by between 5 and 50 percent.

Advanced Conductors

Transmission system capacity benefits when it has the equivalent of a sophisticated air traffic controller. Advanced power flow control technologies are power electronics-based solutions that provide intelligence to how power flows through a system, directing it away from already congested lines to ones with extra capacity without changing generator dispatch or network topology. APFC technologies have flexibility and responsiveness that traditional power flow control approaches like phase-shifting transformers and series reactors can’t match. APFCs have also been singled out in FERC’s Orders 2023 and 1920 for their value in helping America achieve its renewable energy objectives.

Advanced Power Flow Control (APFC)

Software that monitors and analyzes the transmission system and suggests new configurations is another tool to improve its efficiency, reliability, and affordability. Transmission topology optimization does just that by optimizing the operation of substation circuit breakers to reduce congestion that would normally be addressed with the expensive re-dispatch of generation assets. TTO is a low-cost tool to maximize the efficiency of existing grid assets and to improve the overall operation of markets. TTO can also be complemented with other GETs.

Transmission Topology Optimization (TTO)

Four Potentially High-Impact GETs

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