Meridian previously advised that it had reassessed the maximum capacity of the generating units at Manapōuri Power Station so the capacity of each unit could be increased by 6.5MW to 131.5MW rather than the current 125MW per unit.
However, this increase in capacity required dispensation from Transpower and the draft decision declined Meridian’s dispensation application due to concerns about a lack of reactive power in the Southland region if the dispensation was granted.
We have since worked with Transpower to address their concerns and submitted a revised dispensation application to increase the capacity of each unit by 3MW so that each unit would have a maximum capacity of 128MW rather than the current 125MW.
Last night Transpower approved this revised dispensation, effective immediately. While this is not the full capacity increase that Meridian originally hoped for, we expect it will still help with any tight supply and demand conditions that arise on the electricity system, for example during winter peak periods.
Overall station output remains the same at 800MW due to discharge consent limitations. But the additional unit capacity will be valuable when at least one of Manapōuri’s seven units is on outage. As an example, with one unit on outage the maximum station capacity would be 768MW (128MW x 6 units), up 18MW on the current maximum of 750MW (125MW x 6 units).
This change complements our earlier work to increase the capacity of units at Benmore Power Station. Meridian’s GM Generation Tania Palmer says incremental improvements like this can collectively play an important role to build greater flexibility into New Zealand’s electricity system. “The growth of intermittent renewable energy as we move closer to 100% renewables means we need to look for new ways to add flexibility to the electricity system to provide security of supply in peak periods when wind and solar generation may not be available.”
“While this is not the magnitude of unit capacity increase we had originally anticipated, we appreciate the support of Transpower in working with us to find this solution,” says Tania Palmer.