Mercury NZ Limited generates electricity from 100% renewable sources including hydro, geothermal and wind, and retails electricity, gas, broadband and mobile services to residential, commercial and industrial customers in New Zealand; its core generation assets comprise nine hydro stations on the Waikato River such as Arapuni, Maraetai and Whakamaru, five geothermal power stations including Kawerau, Nga Awa Purua and Mokai, and four wind farms including Turitea, Tararua, Waipipi and Mahinerangi; it sells electricity under the Mercury and GLOBUG prepaid sub-brand, bundles broadband and mobile with energy plans for residential customers, and supplies natural gas and electricity to wholesale and large industrial clients including via long-term power purchase agreements. Founded in 1999 and headquartered in Auckland, the company operates nationwide with offices in Tauranga, Hamilton, Rotorua, Palmerston North, Wellington and Oamaru. Recent developments include the 2021 acquisition of five wind farms and development options from Tilt Renewables, the 2022 purchase of Trustpower's retail business followed by its 2023 brand integration into Mercury, expansion of the Kaiwera Downs wind farm with Stage 1 completed in 2023 and Stage 2 underway to reach 240MW capacity by 2027 under a partnership supplying up to 75MW renewable energy to New Zealand Aluminium Smelters, a long-term power supply deal signed in 2025 with packaging firm Visy for up to 115GWh annually over 10 years, and a 2025 strategic investment by Mercury Capital acquiring a 25% stake in Forsyth Barr Group.