Poo powers waste plant
Palmerston North’s wastewater treatment plant is powered by poo.
Human waste is getting turned into electricity to operate the facility.
The city council has just finished laying a pipeline sucking methane gas from the closed Awapuni Landfill to supplement biogas from solid waste to run a new engine to generate almost all of the plant’s electricity.
Operations manager Mike Monaghan said instead of flaring off methane from the solid waste digesters as ‘‘an inconvenient waste stream’’, the system used waste as a natural resource.
Until early 2016, the council was running a separate gas engine at the landfill. After its lease was not renewed, methane gas from the landfill was wasted.
About 700 metres away, the two 2300-cubic-metre solid-waste digesters were not producing enough gas for the engine located at the Totara Rd plant.
The solution was the pipeline, which will provide enough extra gas for the engine to operate almost continuously in future.
Monaghan said the system meant dealing with the city’s wastewater was almost entirely powered by re-use of the waste it was processing.
Water and waste services manager Robert van Bentum said the electricity cost savings at the plant would cover the cost of the pipeline project in less than two years.
The whole project to pipe gas from the landfill, relocate the gas conditioning skid and commission the new system cost about $382,000.
‘‘Not only is the project a beneficial use of a waste gas, but we’re also reducing our energy footprint,’’ said van Bentum.
Totara Rd wastewater treatment plant operations manager Mike Monaghan at the plant.