A large solar water heating array is now online at the Knox County Detention Center.

The solar farm contains 300 panels, five storage tanks and more than a mile of copper piping.

Brian Durr, the district manager for Trane, Inc., said at a dedication ceremony on Wednesday it's one of the largest solar thermal systems in the country.

Solar energy is replacing natural gas as the source to heat water for more than 1,000 inmates.

The $1.88 million project was funded under a federal grant and is expected to save Knox County $60,000 yearly in energy costs.