Meridian Energy has increased the capacity of individual units at its Benmore Power Station as part of a broader programme to get more power out of its assets.

The maximum capacity of each of the six Benmore units has been increased by 5 megawatts (MW) to 95MW.

The company said the station’s output remained at 540MW due to discharge consent limitations, however the additional unit capacity will be valuable when at least one of Benmore’s six units is out of action.

Meridian’s general manager generation Tania Palmer said incremental improvements 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 per cent 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,” Palmer said.

“Driving improvements at existing assets like Benmore is one of the ways we can achieve this,” she said.

Palmer said Meridian was exploring similar opportunities at its other hydro stations.

Meridian had also reassessed the maximum capacity of the generating units at Manapōuri Power Station, in Southland, with its team having identified ways to increase the capacity of each of the seven units by 6.5MW to 131.5MW.

Unlike Benmore, this upgrade required dispensation from the national grid operator Transpower.

Transpower has made a draft decision declining Meridian’s dispensation application due to concerns about a “lack of reactive power” - its ability to manage voltage stability - in the Southland region if the dispensations were granted.

“We will work with Transpower to try to address their concerns ahead of a final decision and remain hopeful of a positive outcome given the potential benefits these unit capacity increases could offer,” Palmer said.

A spokesperson for Transpower said the draft decision was out for consultation with the industry now.

“Submissions are due by June 30 with a final decision by July 7, but we are also continuing to work proactively with Meridian on finding a solution,” the spokesperson told the Herald.

Jamie Gray is an Auckland-based journalist, covering the financial markets and the primary sector. He joined the Herald in 2011.