New Zealand's spring and summer months left hydro-lakes in the South Island at levels below average, meaning Meridian Energy and Contact Energy were more reliant on the wholesale market than their rivals with North Island hydro-storage.
Genesis noted Kupe performed strongly for the half year and overall production was up, with plant utilisation at 94 percent of capacity from 86 per cent in the prior period. Kupe's gas production is supporting generation requirements at its 953 Megawatt gas and coal-fired power station at Huntly ensures a flexible mix of fuels is available, it said.
It said ASX-listed Beach Energy's acquisition of a 50 per cent stake from Origin's Lattice Energy took effect on January 31 and is expected to make it possible to accelerate the planning for phase 2 of the site, including compression and the potential drilling of a new well.
According to England, Genesis's diverse generation portfolio plays a central role in maintaining the reliable supply of electricity when hydro lake storage is low but coal only makes up a small portion of total grid electricity generation and "New Zealand now needs a plan to move away from a dependency on it," he said.
Chair Jenny Shipley said that by 2025 Genesis has committed to not use any coal to generate electricity in normal market conditions and aims to phase it out completely by 2030. The company had planned to wind up the coal-fired units at the Huntly power station by the end of 2018, but extended their life for another four years in 2016.
Genesis's board declared an interim dividend of 8.3 cents per share, payable on April 20 with an April 6 record date. That's up from 8.2 cents a year earlier.
The company narrowed annual ebitdaf guidance to between $350m and $360m from an earlier forecast range of $345m-to-$365m. It reported ebitdaf of $333m in 2017.
The guidance was slightly lower as an unplanned extended outage at Tekapo B is estimated to have a $12m impact on full year performance, largely weighted to the second half of the year. The 187MW hydro scheme is located at the head of the Waitaki Valley in the Mackenzie District of the South Island.
The shares rose 0.4 per cent to $2.39 and have gained 10 per cent over the past year.