The Pennsylvania Power & Light Company formed on June 4, 1920 through the consolidation of eight electric utilities companies serving central and eastern Pennsylvania. The organization of PP&L was a result of a period of intense competition among electric companies in the 1890s followed by a period of consolidation and merger in the decade before the First World War. Between 1917 and 1930, a second wave of mergers occurred largely using pyramiding holding companies that created a unified national network of large regional holding companies. By the late twentieth century, PP&L’s corporate ancestry included more than 1,000 separate power companies, the earliest of which formed in 1882.

In the late nineteenth and early twentieth century, electric utilities companies competed directly for community business. Many began as small gas and direct current electric companies, which limited their distribution over a wide service area, unlike systems using alternating current. Such companies usually reduced their rates below cost to attract new business, resulting in many falling into bankruptcy. Accordingly, stronger companies acquired their weaker counterparts. By 1907, the central eastern portion of Pennsylvania had ninety-two different operating power companies. The intense competition among these smaller, unstandardized electric companies diminished drastically in the period between 1907 and 1917, when the number of power plants serving a system of more than 124 power plants was reduced to only nine.

After the First World War ended, central eastern Pennsylvania’s demand for power continued to grow. The cement, steel, anthracite mining, and other industries became PP&L’s primary customers after the company’s formation in 1920. In addition, the company embarked on a rural electrification program in the 1920s to supply electricity to farms, households, and other businesses in the Pennsylvania countryside; shortly thereafter, the company served about 78,000 customers. In 1926, PP&L built Lake Wallenpaupack on the Wayne-Pike County line to store water for the company’s 44,000-kw hydroelectric plant located on the bank of the Lackawaxen River. Recreation was incorporated as part of the company’s original plan, as Lake Wallenpaupack became a popular vacation spot for swimming, fishing, camping, and boating. The company sustained its efforts to study river systems and their tributaries for hydroelectric and reservoir development, and continued to market their water supply reservoirs as popular recreational and vacation spots throughout the twentieth century, thus advocating positive corporate publicity.

In 1927, the nation’s first power pool was created by an agreement among PP&L, Philadelphia Electric Company, and the Public Service Electric and Gas Company, forming the Pennsylvania-New Jersey Interconnection. The agreement permitted the three companies to supply power to one another in emergencies or in times of high demand, while also serving to lower electric costs for all members of the pool. The agreement served as a model for utility pooling arrangements for decades. By the 1930s, PP&L intensified its rural electrification program, using an aggressive sales campaign aimed at introducing electricity to farmers. Simultaneously, PP&L combatted the effects of the Great Depression by expanding their customer reach through the merger and consolidation of electric companies in Lancaster County and the surrounding areas. By the late 1930s, PP&L grew its customer base to 469,000.

During the Second World War, PP&L became the largest single user of anthracite coal in the world, and employed the use of the world’s largest anthracite coal-fired boilers at its Hauto Steam Electric Station. After the war, PP&L expanded its services further by acquiring electric companies serving Renovo Township and Mauch Chunk (now Jim Thorpe), Pennsylvania, and in 1948 purchased the Palmerton Lighting Company. Upholding its distinction as the world’s largest user of anthracite, PP&L in 1949 opened the Sunbury Steam Electric Station, the largest anthracite burning plant in the world at the time. However, by the 1950s the company anticipated the gradual decline of its anthracite supply and planned for an increase in use of bituminous coal; by the early 1980s, 95% of the company’s coal-fired generation was fueled by bituminous.

PP&L continued its steady growth in the post-war years, opening the Martins Creek Steam Electric Station in 1954 along the Delaware River. It was the first system to use the outdoor design, thereby eliminating the standard building that housed the turbine generation in earlier plants. In the following year, PP&L acquired the Pennsylvania Water & Power Company and with it the Holtwood hydro and steam electric generating plants on the Susquehanna River. Additionally, PP&L acquired one-third interest in the Safe Harbor Water Power Corporation. Expansion continued when PP&L acquired the Scranton Electric Company in 1956, thus greatly expanding its service area by 500 square miles and 95,000 customers. Almost simultaneously, the company decided to investigate the use of atomic power as a direct result of an increase in business. By 1955, other atomic energy projects were underway in western Pennsylvania, but due to the technology’s association as a destructive weapon of war, public and shareholder qualms became a concern for the company. PP&L’s Department of Corporate Communications assembled and distributed nuclear power public acceptance programs and leaflets to help calm the public’s trepidation of the new form of energy. Nevertheless, PP&L decided that nuclear power was too far out in the future, and suspended its nuclear energy program until 1973, when the company broke ground on the Susquehanna nuclear power station in Luzerne County.

In the 1960s, PP&L opened the Brunner Island Steam Electric Station in York County and the Keystone power plant in Armstrong County. These plants’ massive generating power pushed PP&L to invest in its own unit coal trains in 1964, leasing its first fleet from the Pennsylvania Railroad. PP&L was one of the railroad’s largest coal customers. Upon its transition from burning anthracite to bituminous coal, PP&L bought its entire output of bituminous coal to be transported in these unit cars, and ultimately purchased its own 1,000-car fleet. Eventually, the company used the output of five of its own coal mines as well as the output from other company’s mines.

Throughout the 1970s, PP&L adapted to new movements such as consumer activism and environmentalism. The company formed a citizens’ task force, which later set the stage for public participation in site selection for substation and transmission facilities, as well as land use policies. In 1972, the company opened the Montour Preserve, which incorporated educational facilities for classes, workshops, and school fieldtrips. PP&L also helped boost its public image by cooperating with contractors in building a small amount of energy efficient homes using heat exchangers and solar energy. At Brunner Island, the company began fish-farming and, in Hazelton, Pennsylvania, even tried wind as a potential energy source by constructing a wind-driven generator. However, the latter experiment proved inefficient and was shut down by 1982. As cheap energy declined throughout the 1980s, and as the company surpassed one million customers, PP&L embarked on a campaign to reduce the growth rate of customers’ needs for electricity. In addition, the company focused its efforts on marketing using an economic development program to combat a decline in electricity sales.

In the 1990s, PP&L faced another era of consolidation and deregulation, and thus transitioned from a geographically organized electric utility in a monopolistic environment to a functionally organized electric supplier better suited for a competitive global economy. In 1994, the company formed a holding company known as PP&L Resources Inc. to serve as parent to an unregulated subsidiary called Power Markets Development Company, which invested in power projects both domestically and globally. In 1998, PP&L purchased thirteen Montana power plants and shortly thereafter acquired the Montana Power Company’s energy marketing and trading operation. Following this trend, PP&L in 2011 purchased two major utilities in Kentucky, the Louisville Gas and Electric Company and Kentucky Utilities Company. In the same year, the company expanded its reach internationally by acquiring the Central Networks electric distribution in central England, thereby accelerating the growth of its regulated electricity operations. In 2015, PPL Corporation spun off its energy supply business and formed an independent power producer called Talen Energy Corporation.