Power supply still tight as Transpower apologizes, explains situation

Transpower says the power supply remains tight this morning, but hopes it won’t need to ask line companies to reduce load again.

Transpower operates the national power grid (file image).
Photo: Paul Moss Photographer Artist NZ [CC BY-SA 2.5]

Electricity demand hit a record high last night and, combined with insufficient generation, it led to power outages in parts of the country as electricity distributors responded to Transpower’s request to reduce the load on the national network.

Transpower – which operates the network – said: “At the moment we have a very tight generation-demand mix this morning and we will also be managing that with extreme caution.

“At the moment we have not made any demands in terms of demand reduction. We are very focused on getting the lights on and ensuring a very strong and secure electrical system. This is not our intention to reduce demand and turn off the lights.”

“There was a warning this morning to ensure generators are aware that we need sufficient production to meet this demand.

Transpower Chief Executive Stephen Jay spoke with morning report this morning and apologized to everyone who had a power outage on Monday.

“We predict where the peaks in demand expected the day before will be, and we knew last night’s peak was going to be an all-time high for New Zealand,” Jay said.

“Let me explain how the system works… We have spikes [of demand] in the system both in the morning and in the evening, and Transpower has a very important role to play in asking the production companies to offer their production and we then coordinate which generation works next to allow us to respond to the peak in the evening .

“It’s done in real time, and it allows us to make sure the electricity is getting to people’s homes and businesses.

“What we encountered last night was a situation where there was insufficient production to be able to meet that peak, so when there is not enough production to meet the peak and provide a secure system, our only means of controlling and stabilizing the system is to reduce the demand on the system.

“So we released a forecast in the morning based on what the evening peak would be. This allows producers to determine what deals to offer from their generation to hit that peak.

“We then issued the warning in the late afternoon to say it was getting extremely tight in terms of the amount of production to meet demand and then just before 6pm last night there was no enough production to meet demand, so we issued what was called a network emergency.”

The number of people affected is under investigation, Jay said.

“We are asking for a demand response from the distribution companies – the line companies around the towns and the countryside, who then supply electricity.”

The warning was sent to all generators.

“We have requested a response to the request from all distribution activities.

“Utilities have many different ways to control the demand on the system and many would have simply drawn hot water which most stay-at-home mums and dads wouldn’t have noticed.

“Unfortunately the amount of hot water did not allow this to happen in some cases, and this then caused the lights to go out – and again, I apologise.

It was a rare event, the kind of which didn’t happen very often, he said.

“There are very clear procedures within the industry in the marketplace in terms of our response to this, to ensure that the rest of New Zealand and all of New Zealand have a stable system .”

To ask questions

Energy Minister Megan Woods met with Transpower and the Electricity Authority this morning to discuss last night’s blackouts.

Housing Minister Megan Woods said the government was also extending the rules so more people only need a 5% down payment before first-time home buyers can apply for help.

Megan Woods.
Photo: RNZ/Samuel Rillstone

She told the media afterwards that last night was “the highest peak ever in New Zealand in terms of electricity demand, in terms of 7100 megawatts. The normal winter peak we would expect during a very cold winter night would be around 6500 to 6700 megawatts.

“Nevertheless, New Zealanders have every right to expect the power to stay on on a very cold night… so I have asked a series of questions… and will be able to provide updates throughout the day as we receive updates.”

She had asked for assurances that the generators were running at full capacity and assurances about what would happen Tuesday night.

“The questions I’d like to get answered immediately are why the link between the North and South Islands – the HDVC cable – was only running at 50% capacity – there was some spare capacity in this cable for the transfer of more power between the south and the north island.

“There are other issues like for example that Genesis didn’t bring the third Rankine to Huntly and why that didn’t happen. Also, we know in the system, for example, where some of the breakdowns are are being produced – that there was a forecast that there would be more wind generation, but it was quieter than expected.”

She also wanted the communication of the power outages to the public to be investigated.

“In terms of progress…I have asked the Department for Business, Innovation and Jobs to set up a small coordination team…and centralize a lot of issues. “

Call for independent review

Electricity Networks Association chief executive Graeme Peters said nine at noon they had very little time to notify consumers after learning about the discounts.

He also believed in the need for an independent review of the situation.

“We’re all trying to figure out what happened and why it happened, because the electrical system is very complex. There’s a lot of stuff plugging into it and a lot of stuff coming out of it…but clearly There was a massive load in. Why wasn’t there enough generation? That’s a very good question and with independent review, it’s a key question.

“There should be enough generation.”

In a statement, Genesis Energy said: “Yesterday’s market conditions were highly unusual and the product of a number of factors which coincided with a significant spike in evening peak electricity demand due to the cold snap across the country.

“Adverse weather conditions reduced our production capacity from the North Island to the two Tokaanu, where high winds earlier in the day pushed weeds into the water intake, then a sudden drop in the wind in the evening which affected wind generation in the central North Island – including the Waipipi wind farm.As weather conditions improve, we expect Tokaanu’s issues to be resolved and demand returns to more normal levels.

“Available capacity at Huntly was on the market. There was no third Rankine in operation as there was sufficient generating capacity available on the market prior to the loss of generation at Tokaanu and the sudden drop in wind generation. which coincided with peak demand.

“A Rankine unit takes several hours to become operational and would not have met demand under the circumstances during last night’s peak.”

Alan A. Seibert