Winter Power Taskforce
Update On Electricity Demand
The Easter break has contributed to an expected drop in electricity consumption over the past week, with signs that
more people are making an effort to use energy wisely.
The Grid Security Committee’s Winter 2003 co-ordinator Patrick Strange said today that conservation efforts had
accounted for a three per cent saving in national electricity usage over the past week.
“This is up from two per cent the week before but still short of our five per cent target,” said Dr Strange.
The electricity industry has called for consumers to cut electricity usage by five per cent to head off expected tight
supplies of electricity this winter. Dr Strange said he would review the level of savings required for the duration of
winter when he met with the Grid Security Committee next week.
“We have said from the outset that if consumers could lift their savings to around five per cent now, it would reduce
the need for a higher level of savings should a dry winter eventuate.
“Clearly, we have not yet met that five per cent savings target and, as winter approaches, we have seen no improvement
in inflows to the hydro lakes. “While it is encouraging to see consumers making more effort to conserve, we will need to
review the situation thoroughly next week to establish whether we can pause at five percent.”
Dr Strange said that any call for a higher level of savings would need to be supported with a well-directed public
information campaign to encourage and motivate people to conserve electricity.
“As we have seen, it takes effort and time for us all to reach savings of even five per cent – simply lifting the bar
and calling for a higher level of savings is unlikely to produce the sort of result we’re looking for. We have to have
the support systems in place – and we will have.”
Total electricity demand for the week ended midnight Easter Monday was 638 GWh, well down on the 674 GWh total demand of
the week prior but virtually the same as the comparable Easter weeks in 2002 (641 GWh) and 2001 (632 GWh).
“This is a fair result when you consider that national demand has been running about four per cent higher than last
year.
“Also, Easter this year fell about three weeks later than last year and we would have expected temperatures to be cooler
in some parts of the country and demand to therefore be higher.”
He said hydro lakes had not benefited from recent rainfall in parts of the country over the past week.
The potential winter electricity shortfall is due to a combination of higher demand, protracted dry conditions in the
hydro catchments and a reduction in the quantities of gas available for generators to burn to offset the shortfall.
Total inflows to the key South Island hydro lakes for the year to date were only about 73 per cent of average, which
corresponds to a 1 in 20 dry year event.
Dr Strange said that South Island hydro storage levels had continued to decline to 1806 GWh by yesterday, a reduction of
199 GWh on last week and well below average.
“Hydro storage levels typically decline at this time of year. However, the rate of decline is a serious concern
“We did use increased hydro generation last week because of outages at two thermal plants – the Taranaki Combined Cycle
station and one unit at Huntly.
“The Taranaki plant is part way through essential, planned maintenance with much of its gap filled by the New Plymouth
gas-fired power station. The Huntly unit was down over Easter for routine repairs. It was inevitable that we would need
to draw on hydro sources to cover this period.”
Dr Strange noted that the Huntly unit is back in operation, meaning all four units are available again. He said all
electricity generators had agreed to publicly notify any likely maintenance work at their plants which might affect
their generation capability. This information would be distributed to all generators by the taskforce.
“This information will allow the generators to work closely together to make necessary contingency arrangements to
ensure we meet electricity demand.”