MILLINOCKET, Maine — Brookfield Asset Management will spend about $1.5 million to winterize and assess the Katahdin Avenue paper mill for a biomass boiler that will generate about 20 megawatts of electricity, a company senior vice president told the Town Council on Thursday.

The official gave councilors the company’s most detailed explanation yet of the many tasks it faces as it works to wean its Katahdin Paper Co. LLC mill from its profit-killing addiction to oil and reopen it as a top-tier paper manufacturer.

Council Chairman Wallace Paul and other councilors had hoped that the mill, which was temporarily shut down on Sept. 2, would reopen in spring 2009. Thirty-nine workers had been laid off as of Monday with as many as 208 workers expected to be cut between the Millinocket mill and its East Millinocket sister mill. Together the mills, operating as Katahdin Paper, are the region’s largest employer.

It doesn’t look like a quick restart will happen, but councilors said they were impressed with Brookfield’s presentation, which occurred behind closed doors for about two hours. Paul called Brookfield’s work and commitment about as good as anyone has a right to expect.

“They are committed to only one thing — seriously working through this process to see what it would take to make [the restart] happen,” Paul said Thursday. “They are looking genuinely and diligently into making this thing happen and it’s not a simple thing. It’s a big, complex thing.”

Just preparing the mill for an as-yet unknown partner who would install and operate the biomass component is a time-consuming, complex and expensive process. The company will spend about $310,000 winterizing the mill, $300,000 heating it over the winter and $336,000 for a heating unit inside the mill, said Daniel Whyte, a vice president of government and stakeholder relations for Brookfield Renewable Power, a Brookfield Asset subsidiary.

In addition, Brookfield Asset has hired Cianbro Inc. and Babcock & Wilcox Inc. to provide an engineering assessment of the mill and of the costs to upgrade its No. 4 boiler and steam equipment to a biomass system. The biomass system would reuse mill steam and burn tree bark and other wood waste to generate electricity for the mill and the New England power grid.

That work begins with Cianbro next week. The assessments alone could cost as much as $500,000 and won’t be finished until mid-November at the earliest with a mill restart not occurring for at least another eight to 10 months, said Bill Manzer, a senior vice president of business strategy and investments for Fraser Papers, the Brookfield-owned company that manages the mill.

Whyte said the assessments are crucial to luring a biomass investment partner to the mill by providing a step-by-step engineering and cost analysis of the biomass installation process. The engineering work will help determine whether a previous bottom-line estimate of $50 million for restarting the mill was accurate.

Brookfield is undertaking the biomass engineering assessments because it believes in the mill’s workers, state-of-the-art $150 million paper machine and strong customer support, Manzer said. The two biomass firms that the company had been working with earlier this summer left the project in late August, he said.

“We had thought that we would do it in partnership with someone,” Manzer said Thursday.

That partner was supposed to do the work Brookfield is now paying to do. With its many millions in profits, Toronto-based Brookfield also can fund the installation and operation of a biomass boiler but chooses not to.

“It’s not one of our core competencies,” said Jeffrey Martin, a senior vice president of energy management services for Brookfield Renewable Power.

Brookfield Renewable specializes in hydro- and wind power production, Whyte said. Biomass power, which would be used to replace oil as the plant’s steam generator, “is a much more complex business for us,” he said.

Fraser specializes in paper manufacturing. The mill burned 400,000 barrels of oil in 2007, but had dramatically increased savings by lowering energy costs, investing $5 million in the East Millinocket plant’s groundwood mill and finding another $2 million in savings annually that vastly improved the already good-quality paper made at the mill.

Whyte said one critical saving workers achieved will make the biomass installation possible: Since 2004 they reduced the mill’s steam usage by 10 percent annually.

Supplying the mill with 385,000 green tons of biomass — the equivalent of about 400,000 cords of wood — would likely employ many woodsmen and truckers, he said.