Hydro Lakes Now at 1992 Levels

The relentless decline in the level of New Zealand’s hydro-electric storage lakes has continued, and levels have now reached those seen during February of the crisis year 1992.

The hoped-for boost to hydro-electric storage lake levels from last week’s brief wet spell has not occurred. Whilst the Canterbury drought has been broken and a brief cold snap brought snow to parts of the Southern Alps, hydro lakes have benefitted little from the rainfall and subsequent alpine snowmelt.

Lake levels have steadily declined during February and this week reached levels seen at the beginning of 1992 – the year that industry cut-backs, blackouts, water heating restrictions and energy-saving campaigns occurred.

Since 1992, consumption has increased and load levels are now well above 1992 levels. Alternative sources have drifted toward wind generation, with less oil- gas- and coal-fired generation capacity available to maintain supply when hydro is low and winds are light.

The outlook for continuity of supply during a cold winter is now grim, and the impact of any disruptions will be more severe than in 1992. Clean air initiatives have forced many homes to move to electric heating instead of wood-burning, non-hydro generation is inadequate to meet demand, and the ability to transfer energy between the North and South Islands is seriously compromised by the failure to replace aged cable infrastructure.

Daily figures to February 16th show that lake inflows have continued to be seriously low during February 2008, never climbing above 79% of average. Storage lake levels have steadily declined from 2625 GigaWatt hours (GWh) 83% of average on February 1st to 2377 GWh 74% of average on February 16th.

Weekly data issued today, Friday February 22nd, shows lakes have slid further to 2270 GWh 71% of average for the time of year. They were at this level in February 1992.

An energy crisis in New Zealand during the winter of 2008 seems highly likely if weather patterns deliver typical inflows over the coming months. On average, total inflows decline from January until mid-September with regional differences. Typically South Island inflows occur during spring while the North Island lakes benefit from winter rains.

[Compiled from data supplied by M-co.]

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