This is the third in a series of articles on the coming wave of transmission-related innovations and its implications for the electricity sector.
NEMA President & CEO Kevin J. Cosgriff
New technologies are giving electrical grid operators more insight into real-time operations, allowing them to optimize system performance.
A flexible alternating current transmission system (FACTS) is a combination of technologies that together can boost the capacity of alternating current (AC) transmission lines, control voltage fluctuations, reduce power losses over long distances, and generally increase control over the transmission system. That increased control can help integrate renewable energy and increase grid reliability.
Demand response technologies enable grid operators to ask or direct end users to curtail their load to reduce congestion on the power grid during peak times. We’re seeing increased aggregation of demand response resources, and thanks to the Supreme Court’s favorable ruling on FERC Order 745, demand response is eligible to compete in wholesale electricity markets on equal footing with generation resources.
Phasor measurement units (PMUs) are able to measure and record grid conditions, such as frequency, and alert grid operators to potential problems before they cascade into larger outages. The frequency of the grid is similar to a human’s pulse—it is an indicator that something is amiss. Low grid frequency means that there is not enough generation to meet load demands, and the opposite is true with high frequencies. Over 1,300 PMUs were installed with $357 million in smart grid investment funds made available as part of the American Recovery and Reinvestment Act in 2009; that investment accounts for 75% of all PMUs installed on the electrical grid today. Grid operators now have a high level of visibility into the performance of the transmission network serving 88% of U.S. load. Some grid operators have reported that PMUs have reduced the time and cost needed to analyze grid disturbances by 75%.
With real-time thermal monitoring and rating of transmission lines, we could increase the capacity carried over existing lines based on actual weather conditions. Currently, the amount of electricity a transmission line is rated to carry is based on conservative assumptions about the ambient temperature and wind. Transmission lines can carry less electricity when they are warm, so they are rated for hot conditions and other variables. However, they could carry additional capacity at most times when conditions are more ideal.
Some manufacturers make conductors with the capability to monitor and report temperature so that grid operators can know in real time how much more capacity a line can handle before it exceeds its rated limits.
NEMA’s Grid Modernization Leadership Council was established to continue the adoption of a modern electrical grid by providing guidance and recommendations on new consensus-based standards, advocating for favorable government policies and positions, developing and driving messaging and educational materials, promoting voluntary cybersecurity and supply chain risk standards, and participating in all relevant future grid activities. Contact Steve Griffith, its principle staff lead, for more information.