The California Department of Corrections and Rehabilitation said it will add 23 megawatts of photovoltaics at five of its facilities in an attempt to reduce its electricity costs by $55 million over the next 20 years. The projects are being developed by SunEdison, which is selling the power generated by the arrays under power-purchase agreements (PPAs) to the department at costs lower than the rate it is currently paying.

The new arrays will be located at the Chuckawalla Valley State Prison and Ironwood State Prison in Blythe, California Correctional Institution in Tehachapi, North Kern State Prison in Delano, and California State Prison, Los Angeles County, in Lancaster. Most of the arrays will be around 1 megawatt or 4 megawatts, depending on the location’s resources, said department spokesperson Paul Verke.

It’s not the first time the prison system has looked to solar to help reduce its energy costs It completed a 1.2-megawatt array at the Chuckawalla prison in 2006 and a 1.2-megawatt system at the Ironwood prison in 2008, Verke said. Both were also under PPAs with SunEdison.

The prison system doesn’t have a solar installer training program, so most of the work will likely be done by SunEdision. But inmates may still participate in some aspects of the work.

“When we built the last two, inmate labor was used to clear the area and do some pre-construction work,” Verke said. “The more types of employment we can get for inmates, the better.”

The main purpose of undertaking these projects is to reduce the electrical use at the prisons, according to Verke.

“The prison sites are well suited for these types of projects. They have open spaces and are relatively easy to access and close to electric grids,” he said.

The prison system also is trying to become greener.

“It’s a constant goal to reduce our impact on the environment and to reduce costs in both our energy savings programs and renewable energy programs,” Verke said. “We also have energy saving retrofits, already online. We save $50 million kilowatt hours annually just in our retrofit projects.”

Pictured: Chuckawalla’s solar array.