1950s

• Pennsylvania Power & Light purchases Pennsylvania Water & Power Co. and the Scranton Electric Co.
  
• Holtwood Unit 17 is built and goes on line, becoming the world's largest anthracite-fired coal boiler.
  
  
• Pennsylvania Power & Light announces its intention to build an atomic-energy power plant. It joins with Westinghouse to conduct a research and development program of a homogeneous reactor. The program fails; however, PP&L established an atomic power group in the Engineering Department.

• The electric light bulb celebrates its 75th anniversary.

• Martins Creek power plant is constructed and goes on line, hosting the largest single turbine-generator on the Pennsylvania Power & Light system. Martins Creek also pioneers the company's community development efforts, is one of the first "outdoor" type steam electric stations built in the northeast and is the company's first plant designed to burn bituminous coal.

• The three partners in the Pennsylvania-New Jersey power pool's operating group sign a five-party agreement to create the Pennsylvania-New Jersey-Maryland (PJM) power pool. New partners are Baltimore Gas & Electric Co. and the General Public Utilities system.

• Construction begins on Brunner Island power plant on the Susquehanna River near Harrisburg, Pa.

• The winter storm of 1958 blankets Pennsylvania Power & Light territory with up to 14 inches of ice and heavy snow, affecting more than 205,000 customers.