Hydro Lake Storage Improves

Hydro lake storage declined slightly in terms of volume during August 2007, but improved in percentage terms for the time of year. With demand steady and generally below-average inflows, a storm delivered a bonus with whopping inflows on the 11th and 12th.

New Zealand’s hydro-electric lake storage was 1899 GWh (GigaWatt hours), 78% of average, at the start of August 2007, ending the month at 1837 GWh, 81% of average for the time of year.

Daily storage was above last year’s figures on 22 days during the month, consistently so from August 10th. Storage was better than the dry year 1992 and, for most of the month, above that for 2005 and 2006. August is typically a month of declining storage, but the decline as the month progressed was lower than normal, aided by a storm which produced very good inflows between the 10th and 13th.

Nevertheless, inflows were below average on 19 days during August. Of the 12 days when inflows were equal to or above average, whopping inflows of 401% and 352% of average were recorded on the 11th and 12th.

Daily demand was lower than last August on 17 days, peaking at 123.5 GWh on August 15th, lower than the peak loads recorded in June and July. The average daily demand of 113.5 GWh was slightly lower than July’s average load of 116.7 GWh and similar to June’s average load of 114.6 GWh.

Transfers via the Cook Strait cable returned to a more normal pattern, with south-to-north transfers exceeding north-to-south on 18 days.

[Compiled from data supplied by M-co.]

Leave a Reply