Meridian doubts electricity generators will need to use reserved hydro lakes

While welcoming Transpower’s decision to remove potential barriers to generators’ access to contingent storage in certain hydro lakes, including Lake Pukaki, Tekapo and Hawea, Meridian says it’s increasingly unlikely this will be needed.

The change, intended to ensure generators are able to access water in hydro lakes that is held as reserve, will come into effect from September 1 and initially remain in place for two months, says Meridian.

“We’ve had some welcome rain over the last week, and with more rain and higher winds forecast, we’re reasonably confident of getting through spring without needing to access that additional storage,” says Meridian wholesale general manager Chris Ewers.

“Spring is typically a time of higher winds for New Zealand,” he says.

“Meridian has six wind farms that are regularly providing 25% – and occasionally 45% – of our total electricity generation. This, combined with rain in the Waiau catchment where we have Manapouri Power Station, will help us conserve water in Lake Pukaki and build storage for next winter.”

As Lake Pukaki’s operator, Transpower’s announcement means Meridian could – if required – potentially access storage below a lake level of 518m above sea level and lower the lake down to 513 metres above sea level.

That amount of water would provide 545GWh of electricity – almost four weeks of Meridian’s total current hydro generation, says the company.

Meridian also notes there have been some calls for a national power conservation campaign.

“Any decision about power-saving campaigns is one for Transpower, but in our view it’s very premature,” it says.

“We and others in the sector are confident we’re doing everything we can to manage this situation.

“The outlook is getting better by the day, which is reflected in wholesale spot prices more than halving since their high earlier this month.”