The Ministry of Business, Innovation and Employment's New Zealand Energy Quarterly released yesterday said continued dry weather during 2017's final quarter to December resulted in a lower proportion of renewable electricity generation and higher levels of other generation sources, compared with a year earlier.
Renewable generation declined almost 7% from the corresponding quarter the previous year, from 88.1% of generation to 82%.
During 2017's quarters, renewable generation ranged from 79.5% to 86.1%.
The climatic conditions at the time led to a small increase in electricity demand, driven largely by irrigation demand from the agriculture sector. Net electricity generation was about 2% higher than a year ago.
MBIE manager for energy and building trends James Hogan said after the dry spring and early summer in both islands, hydro generation was at its lowest quarterly level since 2015, and 6% down on the previous year.
"While warm, dry and still weather prevailed in the quarter, the renewable share of electricity generation was 82%," he said.
The reduced supply of South Island hydro generation saw a much higher wholesale electricity price for the December quarter of 2017, compared with a year ago.
The average wholesale electricity prices in December last year were double those in 2016.
Wind generation was down 18% for the quarter, geothermal generation was up 2%, but Mr Hogan said it was up to gas and coal generation to "pick up the slack", with respective increases of 46% and 112%.
In order to meet the rise in gas generation, gas production rose by 11% during the quarter to compensate for lower hydro generation, and a rise in the industrial use of gas.
