Recognizing the benefits of synchronized phasor measurements, ERCOT began a project in 2008 to implement this technology in its operations and planning processes. The Synchrophasor Measurement Nodal Operating Guide Revision Request (NOGRR) #142 was recently vetted by the ERCOT stakeholder process. The binding language became effective in June 2015 and requires PMU installations in conjunction with certain new facility installations placed into service by ERCOT TOs and GOs. Communications Handbook, and draft Nodal Operating Guide language, which is binding language within ERCOT. The assessment answers the key questions posed by the ROS and summarizes the status of this technology within ERCOT. The impact of related NERC reliability standards and Federal Energy Regulatory Commission rulings was also considered. The communications handbook provides ERCOT stakeholders with technical details about how to record and transmit synchrophasor data to ERCOT. The binding language outlines requirements for the installation of PMUs by TOs and GOs. Each of these documents was published and presented to the ERCOT ROS for its consideration prior to the end of 2014. Use of PMUs in Operations at the Lower Colorado River Authority Transmission Services Corporation The Lower Colorado River Authority Transmission Services Corporation (LCRA TSC) is a transmission operator in the ERCOT region that operates 5,150 mi of transmission and 380 substations with 3.1 GW of connected wind capacity and TSP2 LAN PMU PMU Local Storage TSP1 LAN PMU PMU Remote Client PDC TSP3 LAN PMU PDC PDC PMU PMU Remote Client ERCOT WAN Local Storage PMU Local Storage Remote Client ERCOT LAN PDC ISG (External) ERCOT PMU Communication Architecture Phasor Archiver-Full PDC Data Stream on Database ERCOT Users Server ISG (Internal) Phasor Archiver (Several Days of Streaming Data) Event Archiver Database figure 2. The ERCOT PMU communication network. september/october 2015 ieee power & energy magazine 39