Fair autumn weather not only means hydro lakes are dwindling but wind farms have been hit by calm conditions during the past fortnight.
Hydro lakes storage was yesterday at 58 per cent of average, prompting a statement of “concern” from Energy Minister David Parker. Wind’s contribution to generation has been less than half of its potential for the past two weeks.
Generators Meridian and TrustPower, which have wind farms in Manawatu, blame “the vagaries of mother nature” and typically calm autumn conditions for the reduced output.
Figures from Energy Link show wind was responsible for 0.6 per cent of generation in the week ended on Sunday and 0.7 per cent the week before.
Wind power can generate around 2.5 per cent of the nation’s needs in favourable conditions and when thermal plants are not being run as hard as they are at present.
The Wind Energy Association said wind generation was predictable in the long term but there were short-term variations.
An association spokeswoman said wind was still a small contributor to the country’s power generation so low output had little overall effect.
New Zealand has one of the world’s best wind resources and the growing number of wind farms can on average generate electricity around 40 per cent of the time.
Parker said that although the East Coast drought had broken, it remained very dry in key southern hydro catchments.
“Unless we have some increased in-flows in the South Island hydro catchments in the next three weeks, further conservation measures will have to be looked at,” he said.
Transpower, which is co-ordinating the industry response, does not favour a large-scale campaign to urge consumers to cut use unless absolutely necessary, but further cutbacks by big industrial users are an option.
Some big users exposed to high wholesale spot prices have already cut production at times over the past month.
The minister said work on a full range of contingency plans was continuing.
“If we do need to move to the next level of response, it’s important we consider all options.”
Earlier this month he said: “There is no realistic prospect of the lights going out – that’s not going to happen.”
Transpower is overseeing Winterpower Watch, a website launched yesterday by the state-owned enterprise and five major power companies.
Group spokesman and Transpower chief executive Patrick Strange said the industry continued to ask the public to be prudent with their electricity use because of low hydro lake levels, which generate two-thirds of the country’s power.
“The weather front which brought snow to the South Island late last week, quickly turned southerly, which brought very little rain to the key southern lakes.”
There are 50 power saving tips on the website, including old faithfuls such as turning appliances off at the wall, and turning the hot water down to 55C.
It also suggests having a video night and inviting all your friends so there’s only one house to heat and going to the big game instead of watching it on television.
At work it suggests staff should be encouraged to defrost food naturally instead of using the microwave.
To reduce demand on the hydro lakes, thermal power plants are being used as much as possible.
Larger users have also been reducing the amount of electricity they use, for example production from the Tiwai Point aluminium smelter has been cut by 10 per cent.
ON THE WEB
Power saving tips are at www.winterpower.co.nz
By Grant Bradley
28 May 2008
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