The power generator and retailer runs the Clyde Dam on Lake Dunstan and has extensive geothermal capacity in the central North Island.
It also has the Taranaki Combined Cycle Power Station (TCC), which has two fast-start gas turbine peaking units.
Separately, the company said it planned to invest $300m to develop a new 51.4 megawatt (MW) geothermal power station at Te Huka, near Taupō, which it expects to be operating by the fourth quarter of 2024.
It said good progress on the 168MW Tauhara geothermal power station development which will supply around 3.5 per cent of New Zealand's total electricity demand by the end of next year.
Growing the development pipeline by securing land access rights to support the development of wind and solar projects.
Operating free cash flow for the period decreased from $371m to $325m, down 12 per cent year-on-year due to lower operating earnings, additional working capital investments in carbon, higher capital expenditure, and higher cash tax paid on stronger earnings in prior periods.
Chief executive Mike Fuge said it was "solid" financial performance despite "unpredictable and volatile" trading conditions.
"This unpredictability has been compounded by a combination of global energy supply and security concerns, exacerbated by the impact of Russia's invasion of Ukraine, with subsequent unprecedented increases in international energy prices, including coal, which has also coincided with a reduction in gas output from the domestic gas market."
Fuge said the retail business had grown its market share in electricity and broadband through innovative retail plans and steady pricing.