The sale of the waste-to-energy plant in Portsmouth to an outside company will save the Suffolk landfill from accepting more household waste.

The move also will keep the Southeastern Public Service Authority from having to spend an estimated $50 million to expand the landfill and build two transfer stations to handle more waste.

“The landfill cell that we currently have is estimated to last until about 2023, which is beyond the life of SPSA,” authority director Rowland Taylor said. “So, there wouldn’t be any real need to have Cell VII.”

The regional trash authority completed the sale of the waste-to-energy plant last week to Wheelabrator for roughly $150 million. The move not only will help the authority pay off more than half its debt, but also all waste delivered to the plant that cannot be processed will now be taken to non-SPSA landfills.

From now on, the Suffolk landfill’s volume will come mainly from construction and demolition waste, dirt and water treatment plant sludge, Taylor said.

“It will slow it down tremendously.”

SPSA officials also have said that the change could help with the odor issue that residents near the landfill have been fighting since last fall. Since construction and demolition waste is less likely to stink while rotting than household waste, the decrease in volume combined with other efforts could help reduce or eliminate the problem.