Fifteen years since Northeast Blackout, reliability remains top PJM priority


By Andy Ott, president and CEO

Fifteen years ago, a high-voltage transmission line sagged into an overgrown tree on a warm summer day in northern Ohio. It caused a fault that triggered a cascading outage that ultimately interrupted electric service to 55 million people across the Northeastern United States and Ontario, Canada.

Public transit systems halted in New York City, stranding commuters in the summer heat. Water treatment plants, hospitals, firehouses, police stations and other critical services were without power, in some cases for days.

The region PJM serves, which was much smaller than it is today, was only peripherally affected. Yet the Northeast Blackout on Aug. 14, 2003, showed just how dependent society had become on electricity. And, in the wake of deregulation in many states, it demonstrated that a significant amount of work was needed to maintain reliability as regions became increasingly interconnected.

A U.S.-Canada task force issued recommendations that spurred a wave of change. The impact on reliability is reflected today at PJM and in its member companies in the planning, construction and operation of the bulk power system and in the markets that have emerged.

Today the industry continues to change as it faces a new wave of technological innovation and market evolution. Yet, despite all of the activity, the lessons from the blackout are still vivid in our memory because reliability remains the most important thing we do.

Lessons Learned

As events unfolded the afternoon of Aug. 14, 2003, PJM operators saw signs of voltage instability and notified our neighboring systems, where the disturbance originated. Since the blackout, PJM and its neighbors have significantly enhanced their level of coordination and collaboration. PJM now has joint operating agreements with its neighbors covering key issues such as the sharing of data. Today regional system operators have a heightened visibility into one another’s systems, which can help to identify trouble early and prevent an uncontrolled outage. PJM and its neighbors also engage in interregional planning, which helps to provide for heightened reliability across system boundaries.

One of the major findings after the blackout was that some system operators had inadequate situational awareness – they did not fully understand what was happening in the field until it was too late, particularly outside their areas of responsibility. In the years since the blackout, new and improved tools and procedures have enhanced operators’ ability to visualize and understand events in the field.

In an effort driven by the U.S. Department of Energy, for example, phasor measurement units (PMUs) have been installed across the region. The technology gives operators a second view of the system beyond what they see through their primary tool, the Energy Management System. And it helps to quickly detect and respond to areas of developing instability. Some experts believe that if the transmission system had been equipped with PMUs and the necessary analytical tools on Aug. 14, 2003, the Northeast Blackout could have been averted.

PJM has developed new tools like the Dispatch Interactive Map Application (DIMA), which allows operators to visualize real-time conditions on the high-voltage electric system beyond just supply and demand. The application includes real-time status of weather, generators, transmission lines and gas pipelines that supply generators.

Market Development

PJM markets have played a central role in enhancing reliability. By providing incentives for participants to invest in plants and equipment, markets have helped keep the system efficient, up to date and reliable. And at the same time, market competition has served to keep energy prices down, which also has benefitted consumers.

In 2007, PJM implemented the Reliability Pricing Model (RPM), which uses a market approach to secure the region’s long-term power generation capacity three years before it’s needed. Then in August 2015, PJM adopted a Capacity Performance product to help ensure that generators are available to run in emergencies, such as periods of extreme heat or cold.

PJM also operates markets to help correct for small imbalances in supply and demand that occur normally throughout the day. The market also helps to ensure that if a large generator unexpectedly trips off, another is ready to take its place. Because of PJM’s markets, the system is more reliable today.

Industry Changes

Prior to the blackout, compliance with industry reliability standards was voluntary. After the blackout, Congress made compliance mandatory and enforceable with financial penalties. While PJM always has complied with, and generally exceeded, industry standards, compliance throughout the industry has since become a much more formal and robust requirement.

As the bulk power system continues to evolve in areas such as the growth of natural-gas-fired generation, renewable energy, energy storage and distributed generation, PJM will continue to evolve and work toward an ever more reliable, more resilient electric system.