New Zealand used more than one million tonnes of coal in just the first half of this year, more than any full year since 2012, as low hydrolake levels and gas shortages continued through the quarter.
Between April and June, the burning of coal accounted for 12 percent of the country's electricity, according to figures released today by the Ministry of Business, Innovation and Employment.
More electricity was generated from coal in the June quarter than any since June 2008.
Coal imports were the highest on record, with 632,000 tonnes coming into the country in three months.
Renewable energy generation in the June quarter fell to the lowest level since 2013, at 75 percent. This is six percentage points lower than the June quarter last year, and was as high as 85.7 percent in December 2019.
In the quarter, generation from hydropower and geothermal sources fell 5 percent each, and generation from gas fell 13 percent.
"Daily [hydro] storage this quarter was well below historical levels and those seen in 2020. Lake inflows this quarter were similar to those seen in 2020, increasing to meet historical averages in the second half of the quarter. However, the amount of electricity that could be generated from hydro was limited and prompted other sources being increased to ensure security of supply," MBIE's release said.
Gas production was the lowest in any quarter since 2011, which reflected a "tightened gas supply", MBIE said.
"Reduced production is mostly due to ongoing deliverability issues at New Zealand's largest gas producing field, Pohokura. In previous periods of low hydro generation, a larger proportion of net gas production was used for electricity generation. Thirty-three per cent of the net production of gas was used for electricity in 2010-2013, compared to 23 per cent in 2017-2020. This quarter, the proportion of gas used for electricity generation was 25 per cent."
Wind power generation rose, with the Waipipi Wind Farm in Taranaki being completed in March this year. Over 650 GWh was generated by wind, the most in any June quarter on record, and the third-most for any quarter. Wind provides just under 6 percent of the country's electricity.