Energy Minister Megan Woods on the causes of last night's power outages. Video / Mark Mitchell
The Government has walked back a statement by Energy and Resources Minister Megan Woods that gentailers made "commercial decisions" when it came to how much generation to have online on Monday night.
Minister David Parker said Woods did not mean to " imply by saying it was a commercial decision that there was some improper motive trying to manipulate the market".
Instead, he backed up a statement from gentailer Genesis that the types of generation online on Monday night were an "operational" decision.
Parker said that the words operational and commercial were effectively interchangeable in this context.
Genesis earlier took umbrage at the allegation it had curtailed generation to push up profits, saying it was being scapegoated by the Government.
Parker was speaking in an urgent debate called to discuss the widespread power outages on Monday night. He was standing in for Energy and Resources Minister Megan Woods, who was away.
He told Parliament two inquiries were now under way into what went wrong.
Transpower has a contractual duty to the Electricity Authority to conduct a report into any threat to security of supply. An initial report has to be given within 48 hours of the event, meaning the report will be due shortly.
Genesis Energy faced scrutiny for not having all available units at the Huntly Power Station burning on Monday evening. Photo / Doug Sherring
Parker gave more details of another inquiry stood up by Woods at the Ministry of Business Innovation and Employment (MBIE).
Parker did not give a timeframe for this report, but said it would take in "all the relevant considerations".
He revealed another issue that appeared to have gone wrong on Monday night.
When it became clear that there would not be enough generation to meet demand, Transpower asked the lines companies to "shed" 1 per cent of their load.
Parker said this figure was later converted from a percentage into a megawatt figure, however something appears to have been lost in translation.
This meant lines companies shed more electricity than they needed to, potentially cutting off households that could have stayed connected.
"[Transpower] sent notices to the individual distribution companies that converted that 1 per cent into a megawatt figure and the translation of that looks like that it wasn't correct at least in some instances," Parker said.
"Some of the lines companies picked that up and they verified the correct number and therefore didn't use the other number than was higher than the figure Transpower wanted," Parker said.
Some lines companies, like Auckland's Vector, picked up on the mistake and sought the correct number, but others did not. These companies shed more customers than they needed to.
He pushed back on the allegation that the power outages had anything to do with the reliability of renewables.
But Parker said that there was a fair question to be asked over whether additional gas generation should have been brought on to manage spikes in demand.
"There's something in that - gas can be brought on more quickly than coal," Parker said.
"There are proper questions to be asked as to whether the system if it does need Huntly for the next few years to sit there as a dry year reserve, as to whether we should have a pool of gas reserve for that purpose as opposed to a reliance on coal," Parker said.
