Reliability Projects

PPL Electric Utilities is a member of the PJM Interconnection, which oversees and operates the transmission system and the movement of wholesale power in all or part of 13 states and the District of Columbia. We need to keep our network strong, not only for our own customers, but also to fulfill our obligations to the larger regional grid.

We continue to invest in our network to make our already strong reliability record even better. Examples of our reliability improvements include:

  • Replacement of aging system equipment
  • Installation of smart grid technology
  • Construction of new lines and substations
  • Rebuilding existing lines with stronger poles and wires
  • Line clearing
  • Devices to guard against damage from lightning and animals

Another PPL Corporation subsidiary, PPL TransLink, develops state-of-the-art projects in the growing market for competitive transmission and key infrastructure. PPL TransLink taps into our vast experience to develop innovative solutions that provide access to reliable, clean, and low-cost energy.

Our system by the numbers

  • We maintain 35,000 miles of overhead distribution lines across our system.
  • Our electric delivery system includes roughly 900,000 utility poles that carry conductors, cross-arms, insulators, transformers, circuit breakers, lightning arrestors, and other equipment.
  • Additionally, we deliver power along 6,500 miles of underground lines, mainly in cities. These lines run through hundreds of manholes and underground vaults, which are inspected each year.
  • We test and strengthen underground power lines each year.


  • Inspections of distribution lines and poles are done regularly.
  • Overhead line inspections identify weak links in the system so damaged or deteriorated equipment can be repaired or replaced.    
  • Each year we perform thermography inspections on about 6,000 miles of distribution circuits, where we use infrared cameras to identify problems before an outage occurs.

Helicopter patrols

  • Routine helicopter patrols of all transmission lines are conducted every year, as well as more comprehensive aerial inspections on a four-year cycle.
  • From helicopter patrols, we use laser beams to measure the distances between transmission power lines and any obstructions, like trees. It's called LIDAR technology, now widely used by utilities across the U.S.

Ground patrols

  • We perform ground patrols of about 1,500 miles of transmission lines annually.

Animal guards

  • We're installing animal guards at substations to prevent birds, squirrels and other animals from entering the electrical facilities and causing outages.

Replacing poles

  • There are more than 34,000 wooden poles on the transmission system. We are replacing all of these over the next several years with stronger steel poles to make our system more reliable.

Lightning arrestors

  • We are adding more lightning arrestors to the delivery system to reduce the impact of adverse weather on electric reliability.