Planning for the Future


At PJM, the word “planning” means assessing and managing the future needs of the electric grid. PJM’s planning team, which consists of engineers, analysts and project managers, ensures that power will be available when you need it today and years into the future. The planning process at PJM includes analyzing and coordinating planned upgrades (such as new transmission lines), connecting new power plants to the existing system and planning PJM’s connections with neighboring transmission systems. PJM conducts long-range planning studies and analyzes future demands on the transmission system in our region. These studies identify changes and additions, such as new transmission lines or upgrades to existing equipment, needed to ensure grid reliability and to maintain the successful operation of the wholesale electricity markets. PJM considers:

  • Expected growth in the use of electricity (for example, population growth in a specific area would drive up demand)
  • Retirements (shutdowns) of existing power plants
  • Public policy (state or other governmental energy initiatives)

Triplex LinePJM is responsible for operating a system of transmission lines, transformers, substations and other equipment with voltages of 100 kV (100,000 volts) and above. These are the transmission lines, supported by large metal structures, that you sometimes see along interstate highways. By comparison, the voltage of distribution lines – the lines many people see in their neighborhoods – is approximately 13 kV (13,000 volts); a typical household runs on 110 volts.

138-230 kV Line500 kV Line

PJM’s annual Regional Transmission Expansion Plan determines in detail the changes needed to the transmission grid up to five years in the future, and projects changes likely to be needed up to 15 years into the future.

PJM Backbone

This map depicts backbone transmission – a group of major high-voltage transmission lines that make up the foundation or “spine” of the grid – in the region PJM serves.

Generation interconnection studies determine whether the existing grid can handle power from a new generating plant and what changes are needed to connect the plant.

PJM works closely with neighboring grid operators, including Midcontinent Independent System Operator and New York Independent System Operator, to coordinate upgrades around shared borders and ensure that facilities in one system do not adversely impact neighboring systems.