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Dynamic Line Rating

The General Line Ampacity State Solver (GLASS) software is a crucial piece of INL’s Dynamic Line Rating (DLR) methodology, a solution that is designed to provide industry with a solution to current transmission line congestion. Glass enables transmission operators to utilize an extra 10 to 40 percent capacity above their current limits, enabling critical infrastructure to be better utilized. Especially in times of extreme power demand, such as recent instances caused by the Bomb Cyclone or 2012 damages caused by Super Storm Sandy, DLR can provide the much-needed transmission capacity to provide power to load generators in extreme need. 

GLASS is state-of-the-art as measured by cost, accuracy and dependability, and will better allow human operators and system planners to make informed decisions and take appropriate actions. Ultimately, GLASS will mitigate transmission line congestion to better integrate wind power, improve the grid as a whole and reduce costs by optimizing current infrastructure and minimizing the need for new transmission lines. 


GLASS makes use of real-time information to help end users determine line ratings for given transmission line sections.

In order to establish limits on the amount of electrical current one transmission line can carry without overheating, grid operators have traditionally relied on Static Line Ratings, which are based on a fixed set of conservative environmental conditions. Power transfer capacity is affected by three main elements: stability, voltage limits and thermal ratings. Optimizing and better managing this power transfer capacity in real time is a primary goal of making the transmission grid ‘smarter.’ Of the three ratings, affecting power transfer capacity, thermal ratings represent the greatest opportunity to improve upon past practice and quickly utilize the grid’s full ability, and this is where INL researchers have turned their focus. 

Widespread adoption of DLR practices will be an important step towards achieving the nation’s renewable energy goals. DLR will enable renewable energy systems to come online more quickly by making better use of existing grid infrastructure.  DLR informs system planners and grid operators of available transmission capacity to help alleviate grid congestion.