From Spain to Tuai – a generator’s long journey

The upgrade of a historic hydro power station near Lake Waikaremoana will boost the plant’s electricity production by enough to power an extra 1000 homes.

The first of three new generators for Genesis’ 60MW Tuai Power Station was switched on last week, after a long journey from Spain that saw it arrive two months late due to global shipping delays.

The 26-tonne generator was then successfully delivered by truck 560km from Auckland, finishing at the end of a narrow, winding road from Wairoa.

Up to 55 contractors and staff were involved in removing the old generator, originally installed in 1939, and replacing it with the 2022 model. The nine-month project was undertaken through various degrees of Covid restrictions, with strict protocols in place to protect workers and the local community.

The whole exercise will be repeated next summer and the summer after that as Tuai’s other two generators, built 10 years earlier in 1929, are also replaced. Once complete, the upgrade will have cost $32 million and taken seven years in planning, production and installation. The engineering project will increase Tuai’s generation capacity by 6MW and improve its efficiency.

Genesis’ Chief Operations Officer, Rebecca Larking, said the project was an example of the company’s commitment to increase the amount of sustainable generation available to the national grid.

“New Zealand is going to need more renewable electricity as the country moves to a lower-carbon future,” said Larking. “In addition to building new renewable generation in the form of wind and solar farms, we also need to extend the life of our existing hydro stations, making them even more productive and efficient in the process.”

Tuai is one of three power stations in Genesis’ Waikaremoana Power Scheme, transferring water from Lake Waikaremoana through Kaitawa (36MW), Tuai and Piripaua (42MW) power stations. Piripaua is also part way through its own overhaul of its two generators, which were first commissioned in 1943. The work will increase their efficiency by up to 3.3%, enough to power an extra 436 households per year.

In 2021 Genesis’ Tekapo Power Scheme completed a $40 million upgrade to increase its safety and efficiency.

In all, Genesis runs eight power stations through its Waikaremoana, Tekapo and Tongariro power schemes, with a combined generation of 689MW.

“A number of the improvements across the power schemes were developed in house by our innovative team members,” said Larking. “These upgrades will future-proof the stations so they’ll continue to produce renewable electricity for New Zealand as the country decarbonises over the coming decades.”