Power Grid Security - Yenra

Planning enhanced transmission energy system reliability

Power Grid - ORNL

In response to numerous inquiries about the recent electricity blackout that occurred in the Northeastern Region of the United States in the summer of 2003, officials at Maine Public Service Company reiterated their commitment to enhanced transmission system security and reliability. According to Brent Boyles, Senior Vice-President of Operations "Maine Public Service is committed to providing highly reliable transmission service within Northern Maine. We have long recognized the unique challenges placed on transmission systems due to deregulation of the wholesale and retail electric markets. These challenges mean that, in a post-deregulation environment, MPS must redouble its commitment to closely monitor and maintain the operating condition of its transmission system. However, despite these efforts, it would be imprudent for MPS, or any transmission system owner to suggest that blackouts cannot occur. MPS's transmission system, like other transmission systems in the U.S., was not initially designed for an open access transmission market. Instead, the system was designed to be tightly integrated with specific generation sources, primarily for system reliability purposes. When utilities such as MPS, divested their generation assets in connection with deregulation, and began to serve deregulated markets, certain unique risks and challenges were created, such as the potential closure of on-system generation not controlled by MPS or the possibility that market driven transmission flows might exceed design standards. Over a year ago we began an evaluation of our transmission system reliability and are continually making investments to improve system security. As part of our normal planning process, we are committed to investing in new transmission infrastructure and evaluating additional improvements to increase system security and reliability."

Unlike the rest of Maine, Maine Public Service Company's transmission system is not directly connected to the United States grid system, but rather the Atlantic Canada or Maritimes Control Area grid system. While not connected to the New England Power Pool (NEPOOL), Bill Cyr, Vice President of Engineering and Asset Management, explained that "if specifically designed protection schemes had not operated correctly, the recent outage in the Northeastern United States could have spread to a larger geographic area. MPS operates the only twenty-four hour per day, seven day per week electric transmission and distribution control center in Northern Maine. Had the August 14, 2003 outage encroached upon MPS's service area, we believe the combination of protective relay schemes and our manned operating center would have helped prevent an outage."

According to Nick Bayne, President and CEO of Maine Public Service Company, "the exact cause of the recent Northeastern blackout will not be known until a thorough investigation is completed. However, while the investigation is ongoing, it would only be prudent to evaluate the impact deregulation has had on transmission systems and system reliability within the United States and Maine. Existing transmission systems are being used in very different ways from their original design and purpose. Every day system operators must attempt to balance reliability with the commercial demands created by deregulation for transmission services. Given the lack of investment incentives to build additional transmission lines and upgrade existing ones, only minor investments in transmission facilities have been made nationwide. Clearly, new transmission standards and incentives to construct transmission networks are critical."

Bayne further stated that "all too often Northern Maine is assumed to have the same electric energy-related issues as the balance of Maine. This is not the case. For example, recent news articles suggested that all Maine electric consumers would contribute to the construction of transmission line costs within New England. Consumers in Northern Maine, which is not connected to NEPOOL, will not be assessed this charge. Further, while the portion of Maine connected to NEPOOL may have excess generation, our region and all of Atlantic Canada are clearly in need of additional generation capacity. Within Northern Maine and the Maritimes Control Area, dependable, dispatchable, and cost effective generation is critical. Unfortunately, the scale of the market and fuels availability make the feasibility of unregulated or merchant generation far more difficult to achieve within Northern Maine."

Concerned about the longevity and availability of generation resources located in Northern Maine, MPS officials are developing long-range plans and options to ensure system reliability and energy availability. These plans include transmission system re-enforcements and other possible actions to address the existing and potential future closures of on-system generation. MPS performs readiness-training drills in cooperation with the North American Electric Reliability Council and New Brunswick Power simulating various contingencies, including a black-start practice drill, to test their emergency restoration efforts in the event of a system-wide failure.

MPS participates with other utilities in the region, including New Brunswick Power, to plan and design systems, policies, and procedures to prevent outages that occur in other regions from cascading into other service territories. MPS conducts numerous system planning studies on an ongoing basis to review the security of the Northern Maine transmission grid, as generation levels change in Northern Maine or adjacent systems.

"We want the customers of Northern Maine to be aware that we review the performance of the power grid on a daily basis and continue to take steps to ensure our transmission system's reliable operation," said Boyles.