Mercury NZ Ltd has selected international technology group ANDRITZ to supply nine new turbines and 13 new generators for a major upgrade of the Maraetai I, Atiamuri, and Ohakuri Hydro Stations in New Zealand.

The refurbishment project will support a reliable electricity supply and significantly increase the plants’ power generation capacity, strengthening New Zealand’s renewable energy system.

The order has a value in the lower three-digit million-euro range and will be included in ANDRITZ’s order intake for 1Q26.

Mercury’s generation assets produce electricity from 100% renewable sources, equating to nearly 20% of New Zealand’s annual electricity. New Zealand already generates around 85 – 90% of its electricity from renewable sources and is on track to reach 98%+ renewable electricity by 2030.

Maraetai I, Atiamuri, and Ohakuri are an important part of Mercury’s Waikato Hydro System, which delivers about 10% of New Zealand’s electricity. Built in the 1950s and 60s, the three plants will undergo comprehensive modernisation. ANDRITZ will supply new turbines, generators, governors, and related electromechanical equipment for the generating units of the plants. This will increase their combined installed capacity by 76 MW from the current 376 MW, adding 87 GWh of generation each year, and ensure long-term operational reliability.

Mercury Chief Executive, Stew Hamilton, said: “Our hydro stations on the Waikato River were constructed from the late 1920s to the 1970s and have worked hard to keep the country powered. We have invested heavily in a long-term refurbishment programme to improve the efficiency and longevity of our hydro stations, to ensure these assets can manage water flow in a way that preserves the environment while optimising power generation. These ongoing improvements will make a significant contribution to a sustainable energy future for New Zealand. We are pleased to embark on the next step in our refurbishment programme with our trusted partners at ANDRITZ.”

ANDRITZ will be responsible for the design, manufacture, installation, testing, and commissioning of the units along with associated auxiliaries. Manufacturing will take place at ANDRITZ’s state-of-the-art facilities in Austria.

This is the fourth major contract awarded to ANDRITZ by Mercury after the rehabilitation of the Karapiro, Aratiatia, and Whakamaru Hydro Stations.