Hawaiian Electric Co. said Tuesday it is seeking more renewable-energy projects to generate power for Oahu by 2020.

HECO requested that the state Public Utilities Commission open a review to allow the utility to ask for proposals for renewable-energy projects from developers and appoint an independent observer for the application process. HECO said it is planning to file the request for proposals in the fall.

“This is the first step in the process,” said Darren Pai, HECO spokesman. “We are open to all types of renewable-energy projects.” He said the company would work with the independent observer to develop the requests for proposals.

HECO said it is seeking renewable-energy generation projects consistent with the power supply plans it submitted with the PUC in April. The company has a 30-year power supply plan designed to get the state to using 100 percent renewable energy.

In HECO’s road map to get the state to 100 percent renewable, the utility said it intends to install a $340 million smart-grid system, build utility-scale wind and solar projects, increase residential rooftop solar, use liquefied natural gas as a bridge fuel, pursue energy storage and retire old fossil fuel plants.

In a letter to the PUC, Hawaiian Electric said it is drafting a request for proposals for the state agency and an independent observer to review.

The announcement comes after HECO terminated multiple renewable-energy projects this year.

HECO ended contracts with SunEdison Inc. for three solar farms that would have generated 112 megawatts of power on Oahu in February.

The solar farms were set to go online by the end of the year and would have sold solar power to HECO for about 14 cents a kilowatt-hour for the duration of their 22-year life spans. HECO said it canceled the projects because Maryland Heights, Mo.-based SunEdison did not meet project milestones and was in a shaky financial situation. SunEdison filed for bankruptcy protection in April.

Hawaii Electric Light Co., HECO’s electrical utility subsidiary on Hawaii island, terminated its contract with biomass facility Hu Honua Bioenergy on March 1.

In May, Hu Honua asked the PUC to investigate HELCO. Hu Honua said the project is about 50 percent complete, with the company spending $137 million to date. Hu Honua said it has $125 million of capital committed to completion of the facility and can be ready to begin operations within 14 months.

In February, after HECO announced its plans to terminate the contracts, PUC Chairman Randy Iwase said he was concerned that the utilities’ actions would “send the wrong message” to future third-party developers that look to do business in the state.