PORTLAND — Maine’s largest city is spending $9.5 million to convert 10 schools and eight other buildings to natural gas. Once it’s completed, natural gas will represent 85 percent of the fuel load used by city-owned buildings.

Ian Houseal, Portland’s sustainability coordinator, tells WCSH-TV that the city will save about $900,000 a year if heating oil remains at $3 a gallon.

The schools will be finished in September, with other municipal buildings wrapping up in November. WCSH-TV says most of the buildings switching to natural gas will be duel fuel, so they can switch back to oil if they need to.