Potential increase to maximum unit capacity at Manapōuri power station

  • Generation news

Meridian is re-applying for dispensation to operate each generating unit at Manapōuri Power Station up to a maximum capacity of 131.5 MW.  This would be an increase of 3.5 MW per unit and could assist with any tight supply and demand conditions that arise on the electricity system over peak periods. 

Overall station output would remain the same at 800 MW due to environmental consent conditions limiting freshwater discharge.  However, the additional unit capacity would be valuable when at least one of Manapōuri’s seven units is on outage.  As an example, with one unit on an outage the maximum station capacity would be 789 MW (131.5 MW x 6 units), up 21 MW on the maximum of 768 MW (128 MW x 6 units) currently available.

The increase in unit capacity is subject to Transpower’s approval of the dispensation application.  The current application follows the Transpower decision in August 2023 to approve a dispensation application to increase maximum unit capacity to 128 MW from the previous 125 MW, having earlier indicated in a draft decision that it would not approve the full increase to 131.5 MW per unit.

Meridian’s engineering and technical experts are collaborating with Transpower to resolve the issues previously identified with the maximum unit capacity of 131.5 MW.  Subject to Transpower’s decision on this dispensation application, we aim to have the additional 21 MW of Manapōuri peaking capability available prior to Winter 2024.

We will inform the market once Transpower has made its decision.