Multiple news outlets report that the companies showcased the solar plant Tuesday at the E.W. Brown Generating Station near Burgin.
The complex features a hydroelectric plant, three coal-fired generating units and seven natural gas-fired combustion turbines. It was approved by the Kentucky Public Service Commission in December 2014 and has a projected cost of $36 million.
Utilities CEO Paul W. Thompson says the facility is already producing electricity, although the plant won't be finished until May or June. He says the facility is expected to produce 19,000 megawatt-hours of energy annually, which is enough to power 1,500 homes for a year.
As of Tuesday, about 13,000 of the 44,600 solar panels have been installed.
Utilities director Scott Straight said the plant was built because customers are demanding more environmentally responsible ways to generate electricity.
Kentucky Environment Cabinet Secretary Charles G. Snavely said helping advance other sources of energy in the state "provides flexibility and makes good sense."
The utilities will use the facility to learn more about solar technology, including how it integrates with existing power-generating units. The company will also examine how commercial-scale solar energy is impacted by factors such as cloud cover.