Watercare is aiming for energy self-sufficiency at its Mangere and Rosedale water plants by 2025 through radical process innovation. This is equivalent to a 37 GWh reduction in power taken from the grid and will set a precedent for a new type of plant.
This will not be achieved simply by energy generation. It requires a fundamental change in treatment processes so they use a lot less energy in the first place. For example, changing the type of bacteria used to treat wastewater will save at least 40% of energy use during the process. For a plant the size of Mangere, energy neutrality will be ground-breaking and a world first.
Watercare has created an Innovations Centre at the Mangere wastewater treatment plant to test and pilot new treatment technologies. It has taken them a few years to grow the bacteria, develop the team and change the processes. Once complete, this initiative will bring considerable innovation to the NZ wastewater sector. It will require no energy from the network and greenhouse gas emissions will be considerably reduced.