Hawaiian Electric Co., the state’s largest electric utility, said Wednesday it wants to offer approximately 50 utility customers on Oahu the opportunity to invest in solar without having to install the panels on their rooftops.

HECO asked the state Public Utilities Commission to approve the “community solar” pilot program.

“Customers who don’t have access to rooftop solar or just don’t want to install panels on their roofs will be able enjoy many of the same benefits as those with rooftop solar,” said Shelee Kimura, vice president for corporate planning and business development at HECO.

The program would reduce the customers’ electric bills by about 45 percent, HECO said.

A typical residential customer who uses an average of 500 kilowatt-hours of electricity a month and who purchases the largest available community solar pilot share will pay an upfront cost of $5,711 plus a $200 enrollment fee.

HECO’s pilot program comes after Gov. David Ige signed a measure in June in support of community based renewable-energy programs.

Through HECO’s pilot, participants would buy a share of the 260 kilowatts of existing solar capacity at Waiau and Campbell Industrial Park power plants. Both facilities are mounted on buildings. The utility chose to set the pilot size at 50 because the 260-kilowatt capacity was calculated to best support that number, said Peter Rosegg, HECO spokesman.

Jeff Mikulina, executive director of the Blue Planet Foundation, called the pilot a step in the right direction but said he hopes later programs would have a variety of structures to allow more Hawaii residents to participate.

“What the utility has proposed has merit, but it represents only one type of community solar model,” Mikulina said. “We envision community solar growing new solar investment, not simply repurposing existing solar panels as the utility pilot proposes.”

Under the program, a participant would receive credit for a share of the electricity output from the solar facility and pay a small maintenance fee.

The amount of the solar credit would be based on the current market rate for utility-scale solar power, HECO said. That ensures that participants are credited fairly for the solar power generated and that nonparticipants do not pay extra, HECO said.

If the PUC approves HECO’s proposed credit, the utility will announce how customers can apply.

The pilot will last up to 17 years because the panels have been in use for approximately three years and have a useful life expectancy of 20 years.