Waste to energy

A cogeneration system at Whangarei’s waste water treatment plant demonstrates the commercial viability of a small-scale waste-to-energy unit.

Overview

Without knowing it, 55,000 residents of Whangarei are contributing to a project that's helping to save the environment, just by flushing their toilets.

The project at Whangarei District Council's wastewater treatment plant is turning methane into free electricity using a cogeneration unit that's powered by a V8 engine.

Methane – a by-product of the wastewater treatment process known as biogas – is damaging to the atmosphere and was being flared off at the plant. Now it is being used to simultaneously generate electricity and hot water – a process known as cogeneration, which is an underused technology in New Zealand.

Related links

 Whangarei waste water treatment plant cogeneration unit case study

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