Needs Assessment Study

CMP's 345 kV transmission system was built and put into service in 1971. Since then power consumption has more than doubled. In recent years, both CMP and ISO-NE have identified certain reliability issues with the 345 kV system that need to be assessed and addressed.

In January 2007, CMP and ISO-NE began a comprehensive needs assessment study of CMP's bulk power transmission system. The scope of the system study included the following:

• A 10-year load forecast to evaluate the system in Maine and how it will continue to interface with the surrounding region;
• A comprehensive analysis of the current system, including planned upgrades to determine transmission system reliability and performance under numerous system conditions and operating scenarios;
• An evaluation of the performance for the current 345 kV and 115 kV system by computer modeling normal and extreme disturbances in accordance with national and regional reliability standards;
• A needs assessment for 345 kV and 115 kV system expansion or upgrades to satisfy performance requirements and minimize reliability risks;
• An assessment of the Maine 345 kV and 115 kV alternative solutions and identification of the most cost-effective solution to achieve the required reliability.

Following several months of intensive research, CMP and ISO-NE completed the study on June 19, 2007. The results, included in ISO-NE's 2007 Regional System Plan, concluded that Maine's transmission system was insufficient to ensure reliable service for Maine's electric customers and to meet new reliability standards.

After completing the needs assessment study, the team went to work to study possible solutions, including both transmission and non-transmission alternatives. To learn more about the alternative studies, visit our FAQ Section. After studying these solutions, CMP determined that a transmission system upgrade was the best solution to improve reliability.