Portland has set a Thursday deadline for accepting proposals to convert rooftops in the city into projects that generate solar-powered electricity.

The city will accept proposals until 3 p.m. on Thursday. Officials say they hope the proposals will be cost-neutral and they anticipate buying power generated from selected providers.

Potential sites include the Portland International Jetport, two schools, a fire station and a library storage facility. The city already has some small-scale solar installations for education purposes on school buildings.