Indianapolis plans to install solar panels at three of its public works buildings in an effort to make those facilities more energy efficient.

The city has put out a request seeking companies or teams of firms qualified to install solar photovoltaic systems at operations buildings and garages. The winning respondent will be required to finance, build, own and operate the system, according to the request for proposals released Monday.

The initiative is the third solar-energy project Indianapolis has undertaken. The city has installed solar-thermal systems, which help to heat water, at three parks facilities, and has put solar panels on the downtown City-County Building.

Those efforts are part of a push started after Mayor Greg Ballard took office in 2008 to make 61 city-owned buildings more efficient with $18 million in upgrades to lighting, HVAC equipment and building controls.

John Hazlett, director of the city’s Office of Sustainability, said the city may examine installing solar-energy systems in additional buildings. An incentive through Indianapolis Power and Light Co., which pays for renewable energy that’s generated and sold back to IPL, has made solar-energy opportunities a bigger priority.

“That makes deployment of renewable energy really attractive,” Hazlett said. “It's certainly having us take a closer look at solar.”

Hazlett wouldn’t discuss specific details about the cost or expected savings from the latest solar endeavor before companies submit responses to the request for proposals.

The deal's financial structure would be similar to that of the park facility improvements. In that arrangement, the city issued a bond at 3.2-percent interest to cover the roughly $391,000 upfront cost for the improvements. That bond will be repaid over about a decade with annual energy-cost savings of about $34,000.

If the city doesn’t achieve the level of savings needed in a given year, the company that installed the solar-thermal systems is required to cover the difference, Hazlett said.

For the latest solar project, the city plans to enter into a contract of up to 10 years with two 10-year options to renew. Potential providers include equipment manufacturers and companies that install and design solar panel systems.

A handful of solar companies are based in Indianapolis, including Ermco Inc., Earth-Solar Technologies Corp. and Johnson Melloh Solutions.

More local solar energy projects have begun to crop up in recent years as technology has improved and utilities have offered incentives, said Patrick Flynn, program manager at the state’s Office of Energy Development. Still, the state lags behind others with sunnier climates or more generous incentives or renewable energy standards.

Some examples of local buildings with solar-energy components include the Major General Emmett J. Bean Federal Center on East 56th Street; the Hilton Garden Inn downtown; and the Broad Ripple Brew Pub on East 65th Street.

“Solar has been around for a long time,” Flynn said. “But it’s becoming more and more of a viable option for companies and government entities.”