A once-controversial plan to power a St. Paul paper recycling plant gained unanimous support from the City Council on Wednesday.

Armed with that approval, the St. Paul Port Authority will now seek a federal loan guarantee to develop a plan to convert rural Minnesota manure and ethnol byproducts into a biogas that will help keep 475 jobs at the Rock-Tenn recycling plant.

Neighbors had initially worried that finding a renewable energy source for the plant could result in a garbage burner in their midst, but after a year-long effort, including studies, lectures and more than two dozen meetings, the biogas plan emerged and won support.

Rock-Tenn has been burning a mixture of natural gas and fuel oil since it lost access to steam energy when Xcel Energy's coal-fired plant on the Mississippi closed. At peak times, the recycling facility uses as much energy as it would take to power about 20,000 homes.

A rural biogas facility linked to Rock-Tenn by a pipeline would save energy and help rural communities manage waste, clean water and help produce nutrient-rich soil, according to the Port Authority.

As part of the plan, Rock-Tenn would have to agree to stay in St. Paul for 10 years.