Underlying profit, a measure that extracts one-off items and is used by the company to indicate ongoing performance, was up 21 per cent at $92 million, representing earnings per share of 12.7 cents, up 17 per cent from 10.9 cps in the previous comparable period.
Investments in gas storage and fast-start gas-fired peaker plants were proving themselves for their ability to allow the company to take advantage of low wholesale prices, said Barnes. "In August, Contact was able to advantage of lower wholesale prices and generate less than it sold to customers.
"The average wholesale spot price for 1H13 was $56 per Megawatt hour, compared with $79 per MWH for 1H12.'
However, volumes of electricity sold were 1 per cent lower than in the prior period.
"Margins decreased for electricity sales by $1 per MWh, reflecting the competition for customers in an oversupplied market," Barnes said.
Some 40 per cent of the Contact customer base was now taking advantage of the company's sector-leading 22 per cent discount for bills paid on time and online - an offer created after Contact dropped its price-leading strategy in the face of major customer losses between 2008 and 2010.
Contact told its approximately 1,100 staff last week that it would be restructuring to cut around 10 per cent of the workforce.
"In an environment of flat electricity demand it is important that we continue to manage our cost base," said Barnes in today's statement. "We recognise that workforce changes are unsettling, particularly for any of our people who are affected and we will support them through this transition."
Other cost savings included reduced maintenance on the company's combined cycle gas turbine plants, reflecting their reduced levels of use and the expiry of Contact's "swaption" for electricity from Genesis Energy's Huntly power station.
The company's health and safety record showed no improvement, with further efforts to "bring us closer to our goal of zero harm," said Barnes.
A long-delayed IT upgrade was scheduled to go live later this year, with capacity to offer new products and ways for customers to interact with Contact, while commissioning on the new Te Mihi geothermal power station was on track for mid-year.