WHAKAMARU BATTERY ENERGY STORAGE SYSTEM.
We're in the early stages of planning a Battery Energy Storage System (BESS) near Whakamaru Hydro Power Station on the Waikato River, north of Taupō.
This site is ideal because it's flat and next to Transpower’s Whakamaru sub-station and transmission lines, connecting to the national power grid.
A new battery storage system will complement our existing renewable energy generation capabilities.
We'll charge up the batteries with power primarily from the National Grid when there’s plenty of power around, and then use it when there's high demand. At times it will be charged from our Whakamaru hydro power station next door. These batteries will help manage the peaks of demand through adjusting the ability to supply electricity when it’s needed across Aotearoa New Zealand.
What could the BESS look like?
We’re still in the early design stage but we think our BESS could consist of up to 180 battery containers on concrete foundations, a substation, cabling, switch rooms and an operations and maintenance building.
Each container is about 6m long and 2.6m high, about the size of an average caravan.

Project site
Whakamaru is the heart of our Waikato Hydro System which supplies around 10% of New Zealand’s renewable electricity. It's also a major node for North Island power transmission.
The hydro station and dam were constructed on the Waikato River in 1956. Its four generation units were refurbished in 2020 which increased generation capacity to 124MW.
Transpower operates two substations, a switchyard and line connections, along with multiple 220kv overhead lines and one 400kv overhead line near the power station.
We're working with the Taupō District Council, iwi partners and stakeholders to keep the community informed on progress with this project.
Please watch this page for updates. People can also contact the project team via email on: whakamaru@mercury.co.nz