Time-lapse of a turbine being dismantled at the Genesis Piripaua hydro station in Waikaremoana. Video / Genesis
Genesis has started a $7.7 million project to upgrade ageing turbines at one of its power stations deep in the bush near Lake Waikaremoana
The Piripaua power station is part way through a two-year overhaul of its two generators, first commissioned in 1943.
The 42MW station is one ofthree in Genesis' Waikaremoana Power Scheme, generating electricity for the East Coast and Hawke's Bay.
Kaitawa and Tuai are further upstream, channelling water from Lake Waikaremoana and recycling it three times through the stations before Piripaua releases it into the Waikaretaheke River.
Piripaua's turbines were last overhauled 27 years ago.
Genesis said in a statement the upgrade would increase their efficiency, or the amount of power they produce from the same amount of water, by 3.3 per cent.
Chief operations officer Nigel Clark said in a statement the project is part of Genesis' commitment to increase the amount of sustainable generation available to the national grid.
The improvements were largely developed in-house by Genesis.
There will also be a number of safety improvements to eliminate health and safety risks that weren't considered when the station was built 78 years ago.
Work on the first turbine started in November and will run through till March, and will then be repeated next year to upgrade the second.
With Covid restrictions in mind, Genesis and Taupo-based contractors MB Century have established eight cabins next to the site.
Work ion removing turbines at Piripaua power station. Photo / Supplied
Eight to 10 contractors can stay there on a roster of 12 days on, two days off.
All staff and contractors involved in the job are Covid-tested prior to travelling to Piripaua, then tested at regular intervals while on site.
Clark says having the cabins available is a huge advantage in getting the project done safely and on time.
"It saves the guys having to go back and forth into the local community and prevents driving fatigue. It's a bit like camping on site – they only have to walk from the cabins to the station and they're ready for work."
Genesis and MB Century also came up with a novel contract arrangement. To prevent costs blowing out if other problems were found during the overhaul, and to share costs or savings if the timeframe turned out to be longer or shorter than estimated, clauses were inserted to cover "as found" components, and to allow the two parties to share "pain and gain".
"This is quite unusual in contracts of this nature," said Clark. "But you don't know what you're going to find when you dismantle a turbine for the first time in 27 years, so those clauses protect both parties."
Workers are having two weeks off over Christmas and New Year. After that, it'll be back to the bush, upgrading the Piripaua station ready for the next 25 years.
The Piripaua power station is one of eight in Genesis' three hydro schemes in Waikaremoana, Tongariro and Tekapo, with a combined generation power of 689MW.
