Renewable energy accounted for 82% of New Zealand’s electricity generation at the end of last year, but dry weather at the time required a large boost from coal and gas generation.
The Ministry of Business, Innovation and Employment's (MBIE) New Zealand Energy Quarterly released yesterday said continued dry weather in 2017's final quarter saw 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 same quarter a year previous, 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, largely driven by irrigation demand from the agriculture sector, with net electricity generation about 2% higher than a year ago.
MBIE's manager for energy and building trends James Hogan said the dry spring and early summer in both islands saw hydro generation at its lowest quarterly level since 2015, and 6% down a 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, 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 Hogan said that it was up to gas and coal generation to “pick up the slack,” with increases of respectively 46% and 112%.
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.
*Simon Hartley is senior business reporter and assistant chief reporter for the Otago Daily Times.