Strong winter demand met by hydro generation
Strong hydro-electric production over winter helped ensure that New Zealand’s electricity supply met record demand
during the cold months of June, July and August.
“Meridian’s hydro-electric plants have been running very hard since early May when high inflows filled up the big hydro
storage lakes,” says Meridian Energy spokesman Alan Seay.
Further high inflows in late June and early July kept hydro storage at between 120 and 130 percent of average over much
of the winter, and kept the turbines spinning hard at Meridian’s eight Waitaki hydro system power-stations as well as at
Manapouri, New Zealand’s single largest hydro station.
The big hydro lakes of Tekapo and Pukaki, which Meridian manages, provide around two-thirds of New Zealand’s hydro
storage capacity. Meridian over the year averages around 30 percent of national electricity production, but when the
lakes are full this can rise to 40% or more.
‘Management of the big hydro lakes is extremely complex, and takes into account a wide range of supply and demand
factors, environmental and recreational factors, as well as financial considerations.”
The hydro supply situation this year was the reverse of 2001 and 2003, when low inflows in autumn and winter meant that
Meridian backed-off hydro generation in order to conserve water, while the Government instituted major conservation
programmes to reduce demand.
The dry winter of 2001 had a serious impact on Meridian’s financial result, lopping around $50 million off its after-tax
profit, which for the year ended 30 June 2002 was $84.0 million. Difficult hydrological conditions in the autumn of 2003
also affected the following year’s result, which was $109.3 million for the year ended 30 June 2003.