It’s good news for New Zealand’s electricity system as we head into the final months of 2026. Transpower’s latest Energy Security Outlook shows national hydro storage sitting well above historic averages at 133%, with South Island storage at 142%.
Transpower also looks at the thermal fuel available to generate electricity when demand is high and renewable generation is low. Its latest outlook says there is sufficient thermal generation capability for the remainder of 2026.
Natural gas generation is part of the mix and gas storage also provides another layer of flexibility. Transpower’s modelling includes gas held at the Ahuroa Gas Storage facility in Taranaki, New Zealand’s only underground natural gas storage facility.
At the beginning of September, Ahuroa held 5.2 PJ of gas available for electricity generation. Transpower estimates that amount of gas could fuel a large combined-cycle gas power station at full output for around three months, ignoring drawdown constraints, or a peaking plant for around eight months.
The outlook reinforces the value of having a mix of energy options available to help keep New Zealand’s electricity system reliable.
