PORTLAND — Ameresco, Inc., a renewable energy company based in Massachusetts, announced today that it has signed an agreement with the city of Portland to provide energy conservation measures to 45 city facilities, including 30 municipal buildings and 15 public schools.

The $9.4 million project will be funded with a bond, said city spokeswoman Nicole Clegg.

It’s estimated that the project will save the city nearly $17 million over the 15 years it will take to complete.

In October, the Portland City Council agreed to borrow the funds needed to make energy improvements with the Barron Center, a city nursing home, receiving the largest share – $2.4 million.

At the time of the vote, city officials said the Portland Exposition Building would receive $450,000; City Hall and Merrill Auditorium, $392,000; $423,000 for the public safety building; and $1.2 million for Lyseth Elementary School.

The project also calls for switching the city from fuel oil to natural gas and installing a 2,000-watt solar array at the Portland Arts and Technology High School.

“The City of Portland is dedicated to sustainability and these investments will help us achieve our goals by reducing carbon pollution,” said City Councilor Dave Marshall, Chairman of the Energy and Environmental Sustainability Committee.