The regional trash authority on Thursday completed a sale of its refuse-derived fuel and waste-to-energy facilities in Portsmouth, which will allow it to pay off more than half its debt and divert waste from the Suffolk landfill.

Wheelabrator Technologies Inc., a subsidiary of Waste Management, purchased the refuse-derived fuel and waste-to-energy facilities for roughly $150 million from the Southeastern Public Service Authority. Wheelabrator assumes management of the operations on Friday.

“The sale of these plants has been long and complicated,” SPSA Executive Director Rowland Taylor said in a press release. “It required the hard work of local and outside attorneys and financial advisors, management of Wheelabrator, the governor’s office, the [Virginia Resources Authority], banks and our own employees.”

The purchase concludes a lengthy process that began more than two years ago. Wheelabrator was chosen from among four companies that submitted bids to purchase the facilities.

The refuse-derived fuel plant and waste-to-energy plant turn most of the municipal solid waste generated in SPSA’s member communities into steam and electricity. The Norfolk Naval Shipyard uses the steam in its ship repair operations, and the power is sold onto the electrical grid.

The regional trash authority will use the purchase price to pay off debt it owes to the Virginia Resources Authority and other lending institutions, and also to repay money owed to the city of Virginia Beach.

In addition, the sale will lengthen the life of the Suffolk landfill, because less trash will be deposited there. In the past, waste that could not be processed at the facilities was taken to the Suffolk landfill. As a part of the new operations contract, however, the waste will now be taken to landfills outside South Hampton Roads.

The move will save the authority an estimated $50 million, the cost of expanding the Suffolk landfill, as well as extend its life past 2018, when the SPSA member communities’ contracts end.