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Electric Transmission System Assets

Electric transmission systems carry large amounts of power at high voltages from generators to substations. Transmission systems must be kept highly reliable to prevent blackouts and ensure robust energy markets. Dynamic line rating technologies have made great strides in enabling the rating of transmission line capacities in real time based on actual line conditions. Synchrophasor technology has emerged as key enabler for improving transmission reliability and operations. Phasor measurement units (PMUs), phasor data concentrators (PDCs), wide area communications networks, and advanced transmission applications are building blocks of a smarter and more reliable transmission system.

The table below includes SGDP program electric transmission system asset expenditures.

SGDP Program Electric Transmission Asset Expenditures

Deployed as of December 31, 2014

Updated March 11, 2015

Electric Transmission System Assets


Incurred Cost**




Phasor data concentrators



Transmission lines with dynamic line rating systems



IT hardware, systems, and applications that enable transmission functionalities



Advanced applications



Other transmission related costs



Total transmission installed cost



* In some circumstances, costs are incurred before devices are installed resulting in a reported cost where the quantity is zero.

Projects only report data on devices they plan to install. Each project installs equipment that best supports their individual goals. Therefore, the number of projects reporting is expected to vary by equipment category. The individual project reporting pages show what equipment that project is installing.

** All dollar figures are the total cost, which is the sum of the federal investment and cost share of the recipient (the recipient cost share must be at least 50% of the total overall project cost).