History of Firsts

Power Generation Technology

Year Event
1917 First major mine-mouth plant -- Windsor Plant, Ohio
1924 First reheat generating unit -- Philo Plant, Ohio
1929 First Triple-compound generating unit -- Philo Plant
1937 First million lb/hr high-pressure boiler (1,250 psi) -- Logan Plant, West Virginia
1941 First very high pressure (2,300 psi), natural-circulation generating unit -- Twin Branch Plant, Indiana
1949 First use of highest-pressure, highest-temperature combination (2,000 psi and 1,050 degrees F. primary and 1,000 degrees F. reheat) -- Twin Branch Plant
1950 First heat rate below 10,000 Btu/kwh -- Philip Sporn Plant, West Virginia
1957 First use of supercritical-pressure steam (4,500 psi) -- Philo Plant
1957 First use of super-high temperature steam (1,150 degrees F.) -- Philo Plant
1957 First use of double-reheat steam -- Philo Plant
1960 First Heat Rate below 9,000 Btu/kwh -- Clinch River Plant, Virginia
1960 First large supercritical pressure generating unit (500 mw, later re-rated to 325 mw) -- Breed Plant, Indiana
1963 First natural draft cooling tower in Western Hemisphere -- Big Sandy Plant, Kentucky
1966 First major combination pumped storage and run-of-the-river hydroelectric development -- Smith Mountain Project, Virginia
1966 First use of control room simulator to train power plant operating personnel -- Cardinal Plant, Ohio
1968 First 1,200-foot stack -- Mitchell Plant (1,206 feet, 367.59 meters), West Virginia
1973 First wide scale, minute-to-minute supervisory system for measuring air quality near coal-fired power plants, transmitting data electronically to computer center (12 networks totaling 65 monitoring stations)
1976 First major research in U.S. on pressurized fluidized bed combustion (PFBC)
1979 First investor owned utility to generate 100 billion kwh in 12-month period
1981 First application of sliding-pressure technique on supercritical-pressure generating unit to maintain uniform efficiency over load range from full to minimal -- Gen. James M. Gavin Plant, Ohio
1987 First steam electric generating unit to operate for 607 consecutive days, a world record established March 13 -- Mountaineer Plant, West Virginia
1990 First combined cycle operation of a PFBC plant in North America -- Tidd PFBC Demonstration Plant, Ohio
1991 First conversion of a nearly completed nuclear plant to coal-fired operation -- Wm. H. Zimmer Generating Station, Ohio
1992 First fossil-fired generating unit in the world to produce 10.6 billion net kwh in a single year -- Wm. H. Zimmer Plant
2009 World's first project to both capture and store carbon dioxide (CO2) on site from a coal-fired power plant. -- Mountaineer Plant demonstration (in partnership with Alstom Power)

Transmission Firsts

AEP has been a leader in the development of transmission technology since the earliest days of its history. AEP energized the first long-distance transmission line connecting a mine-mouth power plant with a major load center in 1917.

Since that time, the company has continued the pursuit of new and better ways to transmit electricity from its efficient fleet of power stations to the cities and industries it serves.

Year Event
1917 First major mine-mouth power plant, Windsor Plant in West Virginia, and long-distance transmission to load center, Canton, Ohio, 55 miles away
1920 First application of carrier-current telephony to transmission lines for system dispatching
1926 Methods developed for transmission line lightning protection
1929 First high-speed carrier-current relaying
1929 First use of automatic frequency and tie-line load control
1935 First ultra-high-speed (one cycle or 1/60th of a second), high-voltage reclosing circuit breaker (138-kilovolts)
1937 First sleet melting of transmission line
1947 First extra-high-voltage line testing up to 500-kilovolts, Tidd Project in Ohio
1948 First aerial inspection of transmission line
1951 First electronic line relay
1953 First extra-high-voltage transmission line (energized at 330-kilovolts), between Sporn and Kanawha River stations in West Virginia
1953 First hot-line maintenance of extra-high-voltage line
1958 First 345-kilovolt interconnection, AEP System and Commonwealth Edison
1960 First large-scale use of helicopters in transmission line construction
1961 First two-cycle, high-voltage air-blast circuit breaker
1961 First bare-hand maintenance of extra-high-voltage line
1961 First use of guyed-V aluminum tower for transmission line
1961 First extra-high voltage transmission line testing up to 775-kilovolts, Apple Grove Project in West Virginia
1962 First two-cycle, 345-kilovolt air-blast circuit breaker
1965 First field research in use of sodium as transmission conductor
1966 First use of laser beam to monitor transmission line
1969 First 765-kilovolt transmission line, between Baker and Marquis stations in Kentucky and Ohio, respectively
1969 First two-cycle, 765-kilovolt air blast circuit breaker
1971 First 765-kilovolt interconnection, AEP System and Commonwealth Edison
1975 First 3,000 megavolt-ampere transformer bank, Marysville Station in Ohio
1976 First sustained operation of ultra-high-voltage (UHV) line at 2,000-kilovolts, AEP/ASEA UHV Research Center at North Liberty, Indiana
1978 First successful testing of transmission current-limiting device
1978 First utility with 100 high-voltage or extra-high-voltage transmission interconnections
1979 First operation of 765-kilovolt station using sulfur hexafluoride (SF6) gas, rather than air, as insulation
1979 First single-phase fault clearing and reclosing of untransposed 765-kilovolt transmission line
1980 First application of Static Var System (SVS) to maintain voltage on transmission grid, Beaver Creek Station in Kentucky
1980 First use of microprocessors in substation protective relaying
1984 First live-tank SF6 "puffer" type circuit breaker (765-kilovolt), Jefferson Station in Indiana
1984 First installation of an Optical Ground Wire (OPGW) in North America (communications between AEP Headquarters and Columbia Center in Columbus, OH)
1985 First transmission line surge arrester installation on 138-kilovolt lines
1986 Nation's highest-capacity transmission network – more than 2,000 miles of 765-kilovolt lines -- in commercial operation
1991 Largest 345-kilovolt series capacitor (788 megavolt-amperes) with thyristor control east of Mississippi River, Kanawha River Station in West Virginia
1994 First use of “open loop” shield wire design with gapped insulators on extra-high voltage lines to reduce power losses
1998 First Unified Power Flow Controller (UPFC) on transmission system, Inez Station in Kentucky
1999 First transmission bridge capacitor, Leslie Station in Kentucky
2000 First back-to-back asynchronous voltage-sourced converter, Eagle Pass Station in Texas
2000 First use of 765-kilovolt transmission line surge arrestors instead of closing resistors in circuit breakers
2001 First 765-kilovolt dead-tank SF6 circuit breaker, Maliszewski Station in Ohio
2006 First use of six-conductor phase bundles in North America for 765-kilovolt line in AEP’s Appalachian service area
2006 First high temperature superconducting (HTS) triaxial cable demonstration, Bixby Station in Ohio
2006 Industry’s first implementation of virtual digital fault recorders
2007 First variable frequency transformer (VFT) in US and on international border. Second VFT in world.
2008 First 765-kilovolt dead tank breaker equipped with closing resistor installed at Hanging Rock Station.
2008 First utility in the US to standardize on detailed functional transmission designs across all operating companies system wide which allowed development and deployment of standard P&C wiring designs at a panel level (in 2008) and at the control building level (in 2011).
2011 AEP’s first prefabricated drop-in control module is installed at the West Millersport Station in Ohio.
2014 First ultra-high frequency partial discharge online monitoring for extra-high voltage transformers in North America
2014 First prevented catastrophic failure of an extra-high voltage transformer using a full online monitoring package (including partial discharge, dissolved gas analysis, etc.)
2014 First North American installation of inter-phase insulators to detune galloping line on the Tanners Creek-Sorenson 345-kilovolt line
2014 First site visit using a variety of virtual tools to allow a core team at the site to collaborate with stakeholders located at multiple physical locations.
2015 First installation of modular ballistic and firewall protection for a 765-kilovolt transformer bank at a 765-kilovolt station to enhance physical security of bulk transmission stations
2015 First application of ground study, using fault current flow concepts and strategies dealing with different soil structures, to design a safe and optimized ground grid for 765, 500, and 345-kilovolt yards at the Cloverdale Station.
2015 First design of a 1.3 megavolt portable resonant test set in North America for use on 765-kilovolt circuit breakers
2015 First use of common frame 345- kilovolt circuit breaker utilizing full, non-limiting phase spacing. Equipment shipped fully assembled to reduce construction time and improve reliability.
2015 The longest live-line re-conductoring project of North America involved a pair of 120-mile, 345-kilovolt transmission lines between Corpus Christi, Texas, and the Lower Rio Grande Valley. Project is also the largest installation of the advanced aluminum composite core conductor in the world.
2015 First enterprise application of Asset Health Center software across a fleet of transformers, circuit breakers, and batteries
2016 First installation of AEP Transmission's BOLD (Breakthrough Overhead Line Design) design between Sorenson and Robison Park stations in Fort Wayne, Indiana features an elegant and high capacity 345-kilovolt design.
2016 First ultra-high frequency partial discharge monitoring of Transmission underground cable in North America
2016 First substation in the country with a fully implemented fiber-based protection and control system at the Flag City substation in Findlay, Ohio
2016 First use of factory built, prefabricated station busses at 138-kilovolt East Willard Station in Ohio
2016 First use of integrated design and 4-D modeling during construction of 345-kilovolt Blessing Station.
2017 First use of aerial photogrammetry and 4-D modeling for progress reporting and as–build documentation during construction of 138-kilovolt Karl Road Station in Columbus, Ohio