New Zealand's Giant Battery Can Power 60,000 Homes at Once, Comprising 70 Containers at a Record-Low Cost

Genesis Energy has opened a 70-container battery storage facility in Huntly, which, at a cost of 130 million New Zealand dollars, has no cheaper competition in the islands.

Seventy white containers are located on the grounds of Huntly, New Zealand's largest power plant, in the Waikato region. Inside each container are lithium iron phosphate battery cells from the French company Saft, power electronics, and control systems. The entire storage facility has a capacity of 100 MW and a storage capacity of 200 MWh. In practice, this means it can supply electricity at full capacity for approximately two hours. According to Genesis's analogy, this amount of energy corresponds to roughly the two-hour consumption of 60,000 households. It is not about continuous power supply to an entire city, but rather a rapidly available energy reserve for periods of peak demand. This is precisely where its main benefit lies. The cost of around 130 million New Zealand dollars, or approximately 1.85 billion Czech crowns, represents record-low costs for a large-capacity battery storage facility in New Zealand, according to Genesis.

Why Huntly, and what exactly do those 70 containers do

Huntly was not chosen at random. The power station is located at a critical node in the transmission grid, from where electricity can be supplied to high-consumption areas, including Auckland, Hamilton, and Tauranga. The storage facility is connected via a substation operated by the transmission system operator Transpower, eliminating the need to build entirely new transmission lines.

Physically, it is not a single giant battery, but a system of 70 independent containerized units. Their installation was carried out by the New Zealand company Northpower. The storage facility charges during periods of low demand or high renewable energy generation and returns energy to the grid during peak hours. These peaks occur, for example, during cold winter mornings and evenings, when electricity consumption in New Zealand rises significantly. Genesis states that the system can respond almost instantly, enabling it to quickly help balance fluctuations in the grid.

The cheapest on the islands, but not in the world

The claim of a record-low price must be understood precisely. Genesis refers to a New Zealand record, not the cheapest battery storage system in the world. The following table compares the costs per unit of capacity:

According to the estimates provided, Huntly is approximately 20% cheaper than Glenbrook and 30% cheaper than Ruakākā. Genesis further states that the project was completed with savings exceeding 5 million NZD compared to the original budget.

For comparison, Contact Energy’s Glenbrook storage facility utilizes 56 Tesla Megapack 2 XL battery units. It employs different technology and a different supplier, with higher investment costs. According to Tesla’s official specifications, achieving a capacity of 200 MWh and a power output of 100 MW would require approximately 52 Megapack units. Both projects are therefore comparable in scale, despite utilizing different technical solutions. Huntly selected technology from the French company Saft and, according to published data, achieved lower investment costs.

On a global scale, however, this is not an exceptionally large facility. According to the IEA, battery storage is one of the fastest-growing technologies in the energy sector, and many projects are designed for approximately two hours of supply at rated power. Huntly fits well into this trend. Significantly larger storage facilities are already operational worldwide, but within the New Zealand energy sector, the 200 MWh capacity at the reported costs represents a significant milestone.

What does this mean for the Czech energy sector

The Czech Republic is currently at a different stage in the development of battery storage. One of the largest operational facilities in the country is the battery in Vítkovice, with a capacity of 10 MW and an energy storage of 9.45 MWh. Compared to Huntly, it therefore has one-tenth the power and approximately one-twentieth the capacity. However, the direction of development is gradually changing. In its overview of projects co-financed by the Modernization Fund, CEZ also lists planned battery storage facilities with capacities of 110, 120, and 160 MWh. Czech plans are thus beginning to approach in scale the projects that are already transitioning into operation in New Zealand.

Legislation is also advancing. The amendment known as LEX OZE III, approved in March 2025, introduced rules for energy storage, grid flexibility, and aggregation. The Energy Regulatory Office is also addressing specific operational and tariff issues, such as the method of measuring electricity drawn into the battery and subsequently returned to the grid, or the conditions for exemption from certain fees. From August 1, 2026, the relevant agenda is set to be taken over by the Electricity Data Center.

From a technical standpoint, there is nothing fundamentally preventing the construction of a storage facility in the Czech Republic with parameters similar to those of Huntly. The challenges remain the operational experience with equipment on such a scale, economic viability, and the willingness of investors to commit the necessary capital to similar projects under the conditions offered by the Czech market.

The story doesn't end there; the second phase is targeting 400 MWh.

Genesis approved the final investment decision for the second phase of the project in April 2026. This phase is set to add another 100 MW of capacity and 200 MWh of storage on the same site and with the same supplier. By leveraging the already constructed grid connection, land, and part of the supporting infrastructure, costs are expected to be lower than those of the first phase. The estimated investment is approximately 106 million NZD. Commercial operation of the second phase is planned for 2028.

Upon completion of both phases, the entire Huntly storage facility is expected to reach a capacity of 200 MW and a storage capacity of 400 MWh. According to Genesis’s calculations, this amount of energy would correspond to approximately two hours of consumption for 120,000 households.

New Zealand is also amending the rules governing the wholesale electricity market. In late September 2026, the Electricity Authority changed the conditions to allow batteries to participate more flexibly in electricity trading and to transition more efficiently between charging and discharging. As a result, Huntly is not just an independent project of a single energy company, but also part of a broader market transformation in which batteries help balance short-term fluctuations in supply and demand. This does not mean that they will automatically replace coal and gas power plants in all their functions. However, they can respond quickly to changes in the grid and reduce the need for certain sources used to cover peak demand.

Seventy containers in the area of a large power plant that also uses coal and gas. At first glance, nothing revolutionary, but it is precisely such facilities that can play an important role in the energy transition: they help store electricity during periods of surplus and feed it back into the grid when it is most needed.