Drought hits Mighty River Power full year generation

Nga Awa Purua Geothermal Power Station. Photo / Rotorua Daily Post

State-owned Mighty River Power's full year generation was 5.2 per cent down on a year earlier, with rising geothermal output unable to replace all the hydro production lost due to drought in the Waikato.

Figures published yesterday show the company generated 5812 gigawatt hours in the year to June, compared to 6129 GWh in the previous 12 months.

The November to mid-May drought in the Waikato had a significant impact on Mighty River Power's hydro generation, Mighty River said.

Inflows were the second lowest since 1927 in the March to mid-May period, with the level of Lake Taupo dropping to within 7cm of the minimum operating range, its lowest level in 40 years.

As a result, hydro generation production fell 14 per cent or 620GWh to 3730GWh. Long run annual average hydro production for the Waikato hydro system was 4000GWh.

Geothermal generation rose 259GWh or 20 per cent to 1562GWh, with the 140 megawatt Nga Awa Purua geothermal power station commissioned in April. Geothermal provided 27 per cent of total production in the year, up from 21 per cent in the previous 12 months.

Renewable generation made up 91.3 per cent of total production, slightly down on 92.8 per cent in the 2009 financial year. The weighted average price fell to $63 per megawatt hour in the latest year, from $67 in the year before.

Mighty River said its retail businesses gained 30,000 new customers in the past 12 months. Residential sales by volume were up by 11 per cent, and commercial sales by 14 per cent.

- NZPA