Unison is responsible for the local electricity lines network in the Hawke’s Bay, Rotorua and Taupo regions. The Commission sets five-year revenue limits and reliability standards for Unison and 15 other electricity lines companies that operate in different regional areas.

In November 2019, the Commission set Unison’s revenue limit through to March 2025. Up until that date, the revenue limit may only be adjusted in certain specified circumstances. Unison applied to the Commission on the basis that its project met the criteria for an ‘unforeseeable major capital expenditure project’, which is one of the specified circumstances. 

The project will supply electricity to support Contact’s construction of the 150-megawatt Tauhara power plant, and subsequently provide a permanent supply from Unison’s network for operating the power plant once it is commissioned in mid-2023. Transpower’s national grid will transport the renewable electricity the geothermal power plant generates to supply consumers.

In December 2021, after reviewing Unison’s application, the Commission consulted on a draft decision that proposed the application be approved. The Commission considered that when it set Unison’s revenue limit in 2019, there was insufficient certainty about the timing of construction of the Tauhara power plant and whether it would be supplied by Unison’s network. 

In making its final decision, the Commission considered submissions on its draft decision and was satisfied that Unison's application met the criteria. The regime is designed to accommodate some change in circumstances to promote the long-term benefit of consumers, and this has helped a renewable energy project like Tauhara power plant move forward.

The Commission issued its final decision on 4 March 2022.