Philo Power Plant

Construction of the Philo Power Plant began in 1922 with the plant designed by Sargent & Lundy.[1][2] Philo began commercial generation with Unit 1 in 1924.[3] This unit initially had a nameplate capacity of 35 MW from General Electric's curtis turbine, but was raised to 40 MW after performing well on its test run.[2] The turbine had a maximum pressure of 600 psi (4,100 kPa) and temperature of about 725 °F (385 °C). It was the first unit in the country that utilized steam reheat.[3] Unit 1 was decommissioned and replaced by Unit 6 in 1957.[4] Unit 2 was completed in 1925 and also had a nameplate capacity of 40 MW.[2][5] The total cost of both units was $10 million.[6] Unit 3 was completed in 1929 with a nameplate capacity of 165 MW.[7][8] The total cost to construct Unit 3 was $17 million.[8] Units 4 and 5 were completed in 1941 and 1942 respectively and each had a nameplate capacity of 85 MW.[4]

Philo Unit 6's turbine in the foreground at the AEP Building in Columbus, Ohio

Philo Unit 6 was the nation's first commercial supercritical steam generator. The unit began commercial generation in 1957 with nameplate capacity of 120 MW.[9] Its steam generator, designed and built by Babcock & Wilcox, had a maximum pressure of 4,500 psi (31,000 kPa) and an operating temperature of about 1,150 °F (621 °C).[9][10] Its steam turbine was designed and built by General Electric that made 3,600 rpm.[10] The unit was able to demonstrate operations at ultrasupercritical levels, but due to the lack of metals able to tolerate the extreme temperatures, the levels were unsustainable.[11] To support the new unit, a 183 ft (56 m) smokestack was erected.[9] The total cost to construct Philo Unit 6 was approximately $19.5 million.[12]

When Philo began operations, the plant maintained a thermal efficiency of 24% consuming 14,000 BTU. Coal used by the plant came by either rail or river barge.[2] Most of the coal burned at Philo was mined within the State of Ohio with some coal coming from West Virginia.[4] Water was sourced from the Muskingum River with its intake being above a dam and was discharged below the dam.[2] At the time of its deactivation, 203 employees worked at the plant.[3]

Philo was deactivated on May 31, 1975. The company cited declining electricity demand during the 1973–75 recession and the facility being surpassed by newer, more efficient power plants.[3] The plant went on standby following deactivation with a single unit used to regulate voltage. Ohio Power remained optimistic that Philo would be reactivated.[13] The plant was eventually demolished in 1983.[14] After the Philo Power Plant was demolished, the rotors from the turbine from Unit 6 were utilized in a sculpture created by George Greenamyer.[15] The sculpture was unveiled in October 1983 as a part of a landscape design project for the newly built AEP Building located in Columbus, Ohio.[15][16]

• List of power stations in Ohio