New Zealand grid

by Chris Morris

New Zealand (NZ) offers a good example of operating an electricity grid with relatively high penetration of renewables, almost exclusively wind.

This is a companion post to the ones previously done on the Australian (AUS) grid:  Australian Renewables Integration: Part 1, Part 2, Part 3.  and the recent updateThe New Zealand gird has is a very similar market structure but with significantly different generation base. However, the same type of issues from moving away from fossil fuels to renewables are occurring.


The NZ grid runs on a market model, similar to but simpler than that of AUS. The Market regulator is the Electricity Authority (EA) — the NZ equivalent of Australian Energy Regulator. The grid owner is Transpower and the day-to-day wholesale market is under the control of an arm’s length subsidiary, System Operator.

The transmission grid is effectively a spine running the length of each island with spurs out to large generators or load centres. There is a relatively high capacity DC link between the two islands. The grid is usually run as a single market entity, with generation and reserves shared between both islands. Figure 1 shows a simplified map.

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 Fig 1    A simplified version of the grid map – the largest dots are about 1300MW and the smallest 200MW

The NZ market, unlike AUS, does not have negative pricing. Instead, must-run bids are put in at 1c/MWh. Most of the time, there is little price separation between the two islands, but in general prices rise as one moves from south to north. This is the way power usually flows. Live generation and market data is shown here and here. The prices are shown in 14 regions, to reflect the role of line constraints in pricing. About two thirds of NZ’s load is in the North Island, and two thirds of that is in the upper half.

The big difference with AUS is that NZ generation is hydro dominated, with thermal plant typically making up only 10-20% of the supply. The total generation is about 44TWh a year (AUS is over 270TWh), of which hydro is about 60%. However, this varies year to year depending on rainfall. Geothermal provides 20%. Wind is less than 10% and solar insignificant. With the different climate to Australia, solar in NZ has a lot less potential. Average sunshine hours across the country are about half of outback Australia’s. One of the original settlers’ names for the country translates as “Land of the Long White Cloud”.

Because of the temperate climate, air conditioning and heat pumps (large daytime electricity loads) aren’t common. The gas fired stations typically provide about two thirds of the difference between renewables generation and load, with coal supplying the remaining third. Generation from diesel fuelled gas turbines (GTs) is only for the very high peaks and emergencies. Figure 2 shows the generation source – the major “Other” contributor is from wood waste boilers driving steam turbines.

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 Fig 2    Annual Generation by source. The hydro and wind contributions are more variable over shorter time periods, even just quarterly. There have been no significant hydro developments since the early 90s.

The 1GW of geothermal runs in the same niche that nukes occupy – baseload at very high load factors, typically >90%. The hydro is based on three main rivers and an underground station connecting a big lake directly to the sea. There is relatively little hydro storage (about six weeks supply when the head lakes are all full), but the country typically has year-round rain with snow-melt in spring. If it doesn’t rain for a month or so, more coal is burnt. The hydro and geothermal generating units are smaller than the usual thermal equivalents. Almost all hydro generator units are less than 110MW, with most in 30-50MW range. That makes it easier to match generation to available flow.

Unlike Australia, the NZ load is highest in winter. Daily electricity usage is about 100GWh in summer and 120GWh in winter, with the near nation-wide shut down during the end of December early January summer holidays, dropping it down to less than 90GWh. Typically, the annual peak load is about 7GW just after dusk in the middle of winter – a calm frosty night. When this occurs, there is typically an anticyclone over the whole country.

The daily load curve has a pronounced double peaked shape. This 40% change makes it quite different to many other grids including AUS, which often have large heavy industry demand as part of their load. Figure 3 shows the maximum and minimum over a recent two-year period. The evening peak is generally higher; but in winter, it can be the morning one. The only big industrial load is a 500MW smelter at the bottom of the South Island which both stabilises the grid and offers rapid short-term demand response if the hydro which mainly supplies it has a unit trip. There is another about 200MW of near continuous demand in big industries, mainly pulp and paper mills, but these often have embedded generation to deal with their waste products and lower their grid demand.

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 Fig 3    all the daily NZ grid load in 2017-18 was between the two lines. The orange Xmas Day was the minimum by some margin with the wrinkles at 5:30 and 20:30 being sunrise/ sunset.  The shape of the curve throughout the year is markedly consistent with the big ramp- up 5am to 8am and the double peaks.  That big 2500MW ramp-up is mainly done with hydros but almost always does need significant thermal input. Power stations that run mainly in the heavy load period 0600 to 2200 are said to be two-shifting.

With geothermal’s 1GW at the bottom of the generation merit order stack, the minimum load is made up by must-run thermal & hydro, plus what wind there is. Like AUS, the wind is unreliable – if anything, worse. Wind has a higher nameplate rating available than geothermal, but wind provides only 40% of the geothermal energy. The windfarms are located across length of the country north- south line (and the main wind comes from the west quadrant), but are concentrated in the lower North Island where the wind is strongest. Total wind farm output can vary from 900MW down to 6MW! Despite the distances, there is significant synchronicity in the windfarms’ generation. The swinging up and downs of total wind supply rarely match grid requirements. The variability has caused short-term operational problems in frequency and voltage management as well as ramp up problems.  At the 3-4 am minimum load period, wind may make up a quarter of the supply.

Chains of hydro stations dam the steeper parts of rivers to use all the head available, with one station’s tailrace at the head of the next hydro lake. They start and stop multiple generators in synch at each station, rather than changing the individual machine’s outputs to match the load. Water needs to be staged during low demand periods to supply the lower dams and to avoid dewatering downstream riverbeds. Figure 4 shows both this loading and the value of dispatchable generation. Hydro spill is minimised as the EA can fine generation companies for not using water to generate, which could raise the market prices. Other than the big floods, or units being out of service on maintenance, the only spill happens just when there is too much generation available for the load and the hydro stations are dispatched off.

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 Fig 4 – Load following by the 3 main hydro rivers. Each river has a different company operating the stations on it. The two low sets of curves on the graph’s right-hand-side are the weekend. This operational pattern is often called two-shifting. The notchiness in the purple line is caused by the big size of the units – full load or off operation.

To help minimize the impacts of rapid load rises, the distribution companies have a system where customers can have short-term non-essential power like hot water and space heaters available to be switched off when required. They are on separate meters and get the power at a cheaper rate (for me, it is about 4c/ unit) The switching is done by injecting high frequencies into the 50Hz waveform which triggers relay switches. The common name for this is ripple control. Across NZ, a nominal 1GW is available, but the typical load on it at any one time is only 100-150MW.

The market price for power is typically around $120/MWh. However, lately as more windfarms come in, the distribution curve of market prices has become bimodal, <$30 when lakes are full and the wind is blowing, >$200 when it isn’t. The merit order stack can be very steep. One thing that needs to be stated clearly (as many don’t understand it) is the market is only for residuals – maybe 10% of the total generation. Most of the retailers have long-term pricing contracts or hedges to cover their customer’s electricity loads. In contrast to Australia, NZ’s domestic power prices have remained remarkably steady over last fifteen years; in fact, slightly dropping since 2015 as shown in Figure 5 NZ power is now cheaper than AUS and less likely to rise as fast.

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 Fig 5    Inflation adjusted domestic power prices.

For those that don’t understand how market dispatch works, the day is divided up into 48 ½h segments – Australia is now 5-minute segments. The generators put in their bids of MW and cost (in terms of $/MWh). These bids are arranged in ascending price order (bottom of stack are must run units at $0.01 cost). The lowest price ones up to the demand are the ones to be dispatched to generate. Spot market price is set by the unit cost of the last unit dispatched. Another name for this is merit order. If there are constraints, like transmission line outages, then these can reshuffle the merit order. If there is too much generation at even minimum price, the ones least needed for security are dispatched off. This means the grid tells the plant to stop generating or maybe just reduce output.

There are two main parts to what companies set as their bid packages (MW & price) to recover their costs – the fixed and variable components. The fixed charges are recovery of the cost of that power station, divided by number of hours it is expected to run. This would include staff & contractors, overhauls, and recovery of the capital costs of building and refurbishing the plant. For thermal plant, the variable costs would mainly be for fuel which includes the carbon charges. This might not be a fixed sum as efficiency varies with load and starting up requirements that don’t generate income can use a lot of fuel. Stop/ Start operation increases maintenance and capital costs. For a hydro plant, the variable charge is the value of that water, at least if they have storage capability. Use it now, or save it? Factors that influence the price is how full all the hydro lakes are, and the longer-range weather forecast. There is also the risk to be factored in of having to buy the power from thermal plants if there isn’t enough water to supply their customers’ load requirements. What this can mean is that some hydros split their bid. Some “must run”, some at a cheap price and some more expensive than coal.

Thermal makes up the difference between available renewables generation offered in on the merit order bids and the actual load. As hydro storage drops or the wind dies, thermal increases its contribution. It also acts as dry period reserve. The level of the lakes is a very important metric major consumers monitor. Most of the hydro is in the South Island and all the thermal in the North.  It is not unusual for the DC to run lightly south at night and heavily north during the day. This may not be the situation for much longer. The major thermal plants are getting old and the government wants them to shut down. Replacement alternative dispatchable power supplies aren’t being built. For the foreseeable future, the grid won’t be secure for both the power and energy requirements without the reserve provided by maintaining the coal and gas fired plants so they can generate when needed.

Transpower does a good planning process, putting out an Asset Management Plan and a transmission planning report every two years. The latter document breaks the country down into regions, looking at the expected load change for every grid exit and injection point as well as switchyards. They then use these documents to prioritise their capital works programme. It then goes to the EA to get authority to increase charges to pay for it. The reports aren’t definitive as they were recently caught out by a major cyclone flooding incident which took out two big switchyards, needing major remedial work and capital expenditure. The major problem the process has is the grid company is wholly owned by the government, which prefers dividends to asset building.

As the grid is relatively small, frequency swings can be often and significant. Frequency control is done by a number of methods. It can be through very short dispatch period adjustments – 20MW up or down type instructions. Or it can be by running some units partially loaded on governor control.  However, it can still be tricky to manage without the buffer of the resources of a larger grid. Frequency swings are larger because of this. In NZ, a 1Hz swing isn’t uncommon while AUS rarely goes worse than 0.2Hz.  This is a problem of small grids, especially those without relatively large stable industrial loads like smelters.

Figure 6 shows the normal ramp up in the spring early morning. Figure 7 shows the effect of the final of the Rugby World Cup held in England the following weekend which many New Zealanders would have got up about 4:30am to watch. The rapid 400MW load increase at half-time caught the SO out. The frequency drop that went with the 10% rise needed major corrective action.

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 Fig 6    A typical Sunday morning load ramp-up

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 Fig 7    2015 Rugby World Cup and effect of half-time. Frequency dropped to about 48.5Hz until ripple control and  reserves brought it back under control.

The grid inertia requirements are generally not seen as an issue because of all the hydro and geothermal units running. Most reserves (also part of the market) are managed by either partially loaded, or in-service as synchronous condensers, hydro units. The latter are connected to the grid, but have the inlets shut and use compressed air to depress the water in the tailrace. This allows the runner to spin in air with relatively little power consumption. Units in this mode can then be used to give voltage support. They can also open the inlet controls and be up to full load in 10-15 seconds – instantaneous reserve. GTs provide slower acting support.

There are problems controlling transmission line voltages into NZ’s biggest city, Auckland, because there are no nearby synchronous generators. The nearest one is at Huntly, a large thermal station complex 60 miles to the south. Even with that, stations in the centre of the North Island have to provide significant voltage support. That shortcoming needs major switchyard investments to correct. The DC link and windfarms are also prone to cause sub-synchronous oscillations in the grid which will eventually need correction, but have not significantly manifested themselves yet.

There was some load shedding in an event two winters ago, when wind generation dropped in the afternoon, too late to bring on slow start thermals for cover. Then they had weed blocking the intake screens at a big hydro, limiting their output; but the main problem was the SO’s grid management model and processes were wrong. They could have just made it through on the generation they had. Much mea culpa about that incident with a lot of revision and validation work done. It is not supposed to happen again.

More big dams are politically unpalatable so there is little hydro development potential. Growth has been accompanied by a gradual move to build more geothermal and wind. However, there are few new sites for geothermal left to develop. Geothermals are also being installed for the two shift operation. To balance this, there is retirement or less operating for the big thermals. The major problem will come when there is not enough thermal to cover the shortfall when there’s little wind and not enough water for hydros. This will especially challenging for the daily ramp up, as well as when covering the unexpected cold day peaks with sufficient reserves. Even now, it is not unusual to have more than 1500MW of reliable thermal plant running to make up the difference between what renewables generate versus the load.

The income derived from thermal plants has to meet their fixed as well as operating costs, so with lowered participation they become uneconomic and will eventually be forced to close. Even a major breakdown could be uneconomic to fix. The government in another virtue signalling move severely restricted gas exploration and development. This will mean future fuel supply is uncertain.  The one coal station is old, though not as old as many in AUS. Coal is imported from Indonesia though the station sits on a coalfield. Transmission line problems and lack of reserves can exacerbate the generation shortage situation. That shortfall leading to rolling blackouts may be only a calm dry, cold winter’s day away.

There is no overall co-ordination of power station development. It is left to each generation entity (four big power companies, two smaller ones, as well as overseas developers or community groups) to evaluate potential new plant on its own merits; looking at the market, their balance sheets and customer load profiles. They then apply for consents to build and operate it. Stations won’t be built unless the owners believe they can pay back their capital and operating costs. This has frustrated many who yearn for a return to the days of centralised planning largesse. Invariably, those decisions were driven by political, not grid management or financial reasons.

Because the current government wants to virtue signal, moving from the predicted 95% renewables by 2030 to 100% while also providing cover as dry year reserve, development of a massive pumped storage scheme at Onslow in the lower South Island has been promoted. Exact details aren’t forthcoming as it is still just a concept, but it is scoped as about 1200MW, 5000GWh. Pricing just for the station went from $4B to $16B in the space of two years of investigation, but the Minister of Energy still thinks it is a good deal. Industry speculation is that the real capital cost of all the infrastructure needed would maybe double that. There is no report or details as to how it will operate or integrate into the market trying to pay its way by arbitrage. It has been discussed as both dry year storage or day to day energy smoothing – it can’t do both. There will need to be massive transmission lines and switchyard infrastructure built to utilise the power if it goes ahead. As well, many windfarms will need to be built to fill the lake. None of these have been proposed, let alone costed. If the government changes at the forthcoming election, the current Opposition have stated they will kill the project. Consignment to the never-to-be-mentioned-again graveyard of politicians’ bad ideas then is inevitable.

There are a lot of plans to build more wind and grid solar farms, but many see them as just tyre-kicking exercises, with few consents applied for and even less construction starting. The windfarms get no direct subsidies from NZ consumers.  Therefore, the economics just aren’t there for building additional plants of this sort. They do get an indirect subsidy, in that they don’t have to meet dispatch where other generators can get fined if they don’t keep their output within pre-notified tight limits. Domestic solar has various subsidies to help assist installation but these aren’t generous. There are no government feed-in-tariffs (FITs) for their output, though some distribution companies offer a nett power (single meter) option.

Almost all generation from existing windfarms is purchased by the large generation companies (if they don’t already own them), who then offset the output against their other generating assets. However, that margin for balancing is now near gone, especially with thermals closing down. The NZ market will need modifications to accommodate the variability. This is especially so with reserves management.

Though it was near thirty years ago, one paper’s cartoonist got it right about creating a complex market.

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For the reasons outlined above, it is more likely that Australia will have operational problems maintaining its grid before New Zealand does. However, the latter is not immune from the same issues confronting other Western countries. It will be interesting to see which government will be the first to publicly say the heresy that net-zero power generation won’t work.

68 responses to “New Zealand grid

  1. joethenonclimatescientist

    As Chris notes, NZ has high percentage of electric generation from Hydro.

    Mark Jacobson of 100% renewable infamous fame – brags about the 45 countries with 50% plus pentration of renewables. Of those 45 countries, the only industrialized countries on the list have very high hydro electric energy generation (NZ, Norway, Iceland, parts of canada) Without Hydro, none of industrized countries come any where close to have high renewable penetration.

    The other countries that make Jacobson’s list are third world countries whose per capita electric usage runs approx 5%-10% of the per capita electric usage of the US or most european countries.

    My apologies if I harp on jacobson, just noting that he uses a tremendous amount of deception throughout his advocacy.

    • This hydro “unfairness” is concern for me too. California and Pac Northwest and to some extent Northeast states via Niagara and Canadian imports view themselves as green because they have access to (often cheap and gov’t funded) hydro. Then the greens in my state say we need match the amount of renewables that the states with cheap hydro have. I try to say each state is in different situation that has to be normalized.

      • joethenonclimatescientist

        good point on the hydro – the only industrialized countries even remotely close to high renewable penetration are those with Hydro, NZ, norway, iceland and other regions such as SE canada pacific NW.

        The only countries with high penetration of renewables only from wind and solar are the 3rd countries – and then only because the per capita electric usage is a tiny fraction of an industrialized country.

  2. I’m watching the Rugby World Cup while reading this. I think it is hilarious that there was such a massive demand spike at 4:30 am as Kiwis tuned in to the footy. They love their rugby in NZ.

  3. I do like the Cartoon! Imagine what happens when the Grid Controls get hacked and held for Ransom.

  4. Very interesting article, but then I’m a long-retired, old fossil and nuclear plant guy. I’m getting near to my “here today, gone tomorrow” date, but I do hope to live long enough to see the net-zero folks understand their unicorn is not going to show up. I’m sure they’ll blame the failure on engineers and utility companies, and here in the USA they’ll blame Trump and his MAGA supporters for all their failures.

    • joethenonclimatescientist

      Serendadhoa – Germany and most all of europe just completed a 36 day period when electric generation from wind average 10-20% of normal. – I doubt the net zero folks will ever comprehend their delusions until there is a massive blackout / brownout due to lack of electric generation. As long as the likes of jacobson keep publishing the 100% renewable studies, they will continue to believe the impossible. Especially in view of the multiple “peer reviews” studies showing the reliability of 100% renewables (every 30 sec test over 3 years) based on “historical weather patterns”.

      Academic fraud in my book which is blessed by “peer reviewed” science.

  5. Very interesting article, but then I’m an old, retired, fossil-nuclear plant guy. I’m close to my “here today, gone tomorrow” date, but hope to live long enough to see the advocates of net-zero understand their unicorn isn’t coming. Unfortunately, they’ll blame scientists and engineers for not developing ways to generate power which is free, pollution free, and kind to Mother Earth. Here in the USA they’ll also blame Trump and his MAGA supporters, of which I am one.

  6. In the early days, reliability was most important.
    Now, profitability is most important.
    Coal must be replaced, it is too reliable.

    In truth, someday we may run low on gas and oil and we should build clean coal and use it to make the gas and oil last longer.
    We need climate science to question consensus, determine more about natural climate factors which have been dominate for millions of years and will most likely continue to be dominate for millions of years to come.
    Water is abundant and water changes states. When we, humans, engineers, try to control temperature, we use substances that change state, we do not work with substances that have a trace influence.
    Look to water, ice and water vapor. In warmest times more polar ocean evaporation and then snowfall rebuilds the sequestered polar ice. Polar ice is pushed into the turbulent salt water currents where it thaws and causes untold cooling with cold currents sent back to tropical oceans. The most cooling from this ice thawing is in the coldest times but the IR out from forming the ice was in warmest times. This dynamic factor is not considered in climate energy balance, ice is not considered.
    Science should always question, it should never trust consensus!

  7. R. L. Hails Sr. P. E. (Ret.)

    An interesting article, to which I add comments. NZ is unlike most other nations so their solutions (large hydro, rain in mountains) will never be transferable. There is a curious statement, “….geothermal runs in the same niche that nukes occupy –…” which needs development. But the basic problem: Who is we? Who gets the bill, or the payment, long term and monthly? is universal but not resolved. And the technical issue; is fire really bad, was answered here, a talk by a Noble prize winner and world changer, Dr. John Clauser:

    I summarize. There is no climate emergency and scientists must not lie.

    If NZ gets it wrong, their economy will collapse, and people will starve. These facts of life exist everywhere.

    I engineered a score of nukes, two score fossil plants, and assessed advanced technologies, over 45 years, all in the US.

    • ” same niche that nukes occupy “. One reason is they are inflexible for that system – one with occasional 2% frequency variations. The ‘diesel fuelled gas turbines’ do the two shifting.

      “governor control” is probably ‘frequency control governing’. My experience with a very small grid in ‘island mode’ made me realise that on large grids frequency control as an operating mode is not given high importance. Beyond 2% in swing one approaches service life limitations.

      • melita – yes the frequency control is mainly done by some units running on the governors backed up by short order dispatch. As you note, it can only be done because our grid is isolated and small.
        The two shifting is done mainly by hydro as Figure 4 shows but that is by starting and stopping the many small units rather than changing the loading on them.

    • RL – geothermal in NZ are baseload plant. they are very hard to change load as melita noted. Often the only way to reduce is vent steam – until operators can shut in wells -an energy waste. Geysers in the US is a unique field, dry steam and almost hot dry rock. That can two-shift. Almost all the others worldwide are liquid dominated resources.
      You are right. NZ is NZ, made that way by circumstances. What we do is not an example to be followed by others.

  8. I’m confused by this piece. It’s a great overview of the existing NZ grid and its impressively high levels of renewables. And then it shifts to stating as fact that NZ will have major problems going from a ~90% renewables grid to net zero, with zero explanation of why any fossil fuels would be needed to maintain grid stability and reliability.

    • joethenonclimatescientist

      Tamlyn – NZ has 56% of electric generation from Hydro which provides a very strong base load of energy, along with very stable. The problem with wind & solar is that they are highly variable. Winds has dual problems with stability A) long wind droughts 4 hours to 3-4 weeks at a time & B) even within the hour, wind speed flucuate greatly on a minute by minute basis. 8mph to 15 mph flucuations, vs a steady / constant wind speed. Those two different types of flucuations create stability problems.

      Also google the following: (I would link but it is a pdf). It is jacobson list of 45 countries. Two items to note A) High Hydro electric generation dominates the list and B) the list omits the per capita electic usage which is very deceptive for those countries with low hydro also have very low per capita electric usage.

      45 Countries Whose Electricity Generation in 2020 or 2021 was 50-100% Wind-Water-Solar (WWS)
      (Including Nine With 98.5-100% WWS Generation) and Two States With
      97.2-120% of Their Electricity Consumed From WWS
      By Mark Z. Jacobson

    • Tamlyn – NZ does have a very high level of renewables on the grid, but these are the old ones, hydro and geothermal. Typically, they are 80-90% of the generation. The unreliable wind comes and goes. NZ is already having problems with phasing out thermal at its existing levels of unreliables penetration – so it is no great leap of logic to say going to a system with no thermal backup will be a major problem.
      The generation companies have been telling the government of the issues, but the government won’t listen. From a recent newspaper article, one CEO said.
      “While we have a lot of wind and solar generation capacity coming on stream, the reality is they are intermittent sources of energy; they come and go when the wind blows or the sun shines.
      “At the moment, the majority of that is backed-up by assets like gas turbines which can come on at short notice. The Ministry of Business, Innovation and Employment — MBIE’s assessment of the nation’s gas reserves suggests the 2030s look problematic from that perspective. And we’ve yet to identify a customer segment that is looking for cold showers by candlelight.
      Keeping the lights on is essential.”

      • “so it is no great leap of logic to say going to a system with no thermal backup will be a major problem.”

        Why? If they can already run at 90% FF-free, surely extending the actual generation capability to 100% would not be hard, if it’s not there already. That doesn’t need new dams, just new generators. Hydro comes with good medium term storage. Then, as in Tasmania, they can use wind when available, hydro when not, and still keep the dams full.

      • Nick, I see you still don’t understand the difference between energy and power. And grid operators have to cover as 99.999% or better supply meeting demand. It isn’t rare for thermal to be 40% of the NZ generation, especially when it hasn’t rained for a month or so. And as I stated, they need thermal to cover both the rampup plus provide the reserves, just like SA does. Look at the data for 1600 to 1900 last night when they had to bring the diesel engines in as well. There diesel was providing almost as much as wind.
        With regards Tasmania, how did that do the other year when the DC was down and just relying on their hydro and wind?

      • Sorry -I’d forgotten AEMO runs a day late on their fuel mix. It was 1600 to 1900 on 29th September

      • Right now with a cold front crossing the country and gale warning out for parts, wind is on 20% but the thermals are still doing 10% of the generation. By Wednesday when the anticyclone is sitting over the country, those numbers will have more than reversed.

      • Chris,
        “And as I stated, they need thermal to cover both the rampup plus provide the reserves”
        Why can’t hydro cover the rampup just as well? And hydro has plenty of reserves. The only reason not to use hydro all the time is that long term, rin won’t keep filling the dams fast enough. But If part of the load can be shifted to wind when available, that fixes that.

        Tasmania? Their problem was that when BassLink started, they got too enthusiastic about selling power at mainland prices and ran down the dams. Then they were hit with a triple whammy of no link, low dams and drought. They learnt from that. They use cheap Vic wind power when it’s on, and use their water more prudently when the price is high. Often average flow is Vic->Tas. The dams have recovered, and have years of storage. And soon enough there will be a second link.

      • Hydro can’t cover the rampup because it is generating baseload as well. Only so much capacity. More capacity for rampup, less for baseload. And they can’t just add more capacity (your simplistic suggestion) because the dam lakes have no storage -typically less than 5GWh each. Staging takes real time. The storage is also in the wrong island.
        You come up with all these expensive options Nick.
        Who is going to pay for it? Isn’t that why industry left SA – your power bills are too high?

      • joethenonclimatescientist

        Nick Stokes comment “Tas. The dams have recovered, and have years of storage. And soon enough there will be a second link.”

        Nick – you highlight one of the major fallacies in Jacobson 100% renewable study, though I suspect in you glee, you overlooked the fallacy.

        NZ , Norway, SE Canada are countries and regions of the world that are fortunate enough to have Hydro in large quanities. The majority of the world isnt so fortunate. Those areas of the world need the water behind the dams for irrigation and basic water survival needs. Jacobson includes the water behind the dams as part of the huge back up storage capacity. Yet releasing sufficient water to cover the needed backup storage problems for the long wind droughts will create massive ecological disaster. Depleting water necessary for basic human survival.

      • Chris:
        “And they can’t just add more capacity (your simplistic suggestion) because the dam lakes have no storage -typically less than 5GWh each.”

        Really? According to this source
        “This is still significant considering that there is 4.5TWh total national hydro storage capacity at present.”
        or this
        “The hydro lakes are not large, containing just 4TWh of storage in a country with annual electricity consumption of 40TWh.”

        From that latter quote, that is at least a month’s storage. There shouldn’t by a problem with daily rampup.

        Or did you mean 5 TWh, not GWh?

      • joethenonclimatescientist

        Nick – let me respond to you question to Chris regarding “Really? According to this source
        “This is still significant considering that there is 4.5TWh total national hydro storage capacity at present.”
        or this
        “The hydro lakes are not large, containing just 4TWh of storage in a country with annual electricity consumption of 40TWh.””

        A) the first point is that you should never rely on an advocacy report for any scientific information. You should know better than that.
        B) As I noted above, water behind dams is primarily for irrigation and other human water needs. Releasing water solely for electric generation, especially emergency electric generation creates potential for ecological disaster. Its noted that there is a “one month” supply behind the damn. That is an exceedingly thin margin.

      • Chris Morris

        It is too much to expect you to understand the subject, but I do wish you would actually read your links and compare to the post and others’ comments before commenting. The articles refer to the proposed Lake Onslow which I specifically referenced in the post. They have the same storage numbers I used.
        I said 6 weeks supply for the existing lakes. On the load I quoted, that is 5TWh. And guess what the storage is if all the lakes are full to the brim according to Transpower? – 5TWh. In practice, it is usually about 40-60% full – the catchments rely on rain from different weather systems. The bottom 1000GWh is contingency and severe countermeasures need to be put in place if it drops to there, so the working range isn’t that much. It can drop 20-30GWh a day in dry weather, like it did July to mid-September this year. Take out a single unit plant for survey like NAP or TMI – each provides about 12GWh a day – hydro covers that if there is enough water in the lakes. E3P would need even more.
        With regards the (hydro) dam (/station) lakes, none on the Waikato are above 3GWh storage. I have the data sheets for all the lakes in working levels, GWh and CMDs in my work bookcase. Other than Benmore, none on Waitaki or Clutha are either. Of the storage lakes, Taupo, Pukaki, Hawea, Te Anau don’t have a power station on their outflows, just control gates into a canal or a riverbed. Ohau, Wanaka, Wakatipu are totally uncontrolled – no dam, power station or control structure. Tekapo has a 25MW station which discharges into a canal. Manapouri discharges through a station directly to the sea. That is why you can’t add peaking capacity or use them for useful pumped storage. More peaking, less baseload as energy unchanged.
        With regards Onslow, the scheme is so stupid, that only academics (or politicians) would believe in it, to misquote Orwell. It isn’t economic – even fag packet maths tells people that. It would need to average $1M a day profit in arbitrage to pay back just the capital costs. And the stations to fill the lakes don’t exist. Wind isn’t economic at current prices, let alone market rates from overbuild. It would NOT be a generator, just a load centre which can store previously generated power at a discount. And it is in the wrong island. The thermals it was supposed to replace are north of Taupo.
        Correcting something Joe wrote, irrigation here does compete for water but most of the high irrigation or other use demand is either below the bottom dam or in different catchments to hydro rivers.

  9. Without the fortune of being a hydro-dominant society (like Norway), they’re just aren’t that many states like California with enough retired upper class males who need a Tesla to drive to the golf course every day.

  10. I am standing for the ‘ACT” party in this year’s general election in NZ. I left the conservative ‘National ‘ party for this very reason – that their climate aspirations for ‘net zero’ by 2050 were nothing more than intellectually lazy politicking. On current technologies, there is no question that to achieve ‘net zero’ will result in economic ruin and hardship. I have a Masters in Climate Science and Policy and was an IPCC Expert Reviewer (for what that’s worth) and are continually astounded by the complete ignoring of careful scientific measurements showing not much happening to the dynamic climate/weather system, both home and abroad. ACT will benchmark our emissions reduction performance against trade partners – none of whom I believe are taxing agricultural methane.

  11. Thanks, Chris. Interesting, as always.

  12. R. L. Hails Sr. P. E. (Ret.)

    An issue which has, perhaps, great potential but rarely discussed is HVDC. When I worked on it many years ago, the longest conductor on earth was 10 cm long. This should warrant a separate article. The NZ experience may hold great promise to transmit energy over long distances, a game changer. What are the design conductor numbers? What are the technical and cost benefits and down sides? How much HVDC experience does NZ have in real world conditions?

    Chris, thank you in advance.

    • RL
      When it was built, it was supposed to have been the second undersea one – the first between two islands in Denmark.. If it hadn’t been built, there wouldn’t have been the SI hydro, just coal and nukes in the North Island. The NZE boss drove it through against a lot of political opposition.
      I don’t take much technical interest in the DC (it’s the other side of disconnector) and I never even visited Haywards terminal, though our first child was born while we lived in the construction village there.
      What I can tell you is it is rated about 1200MW – 700MW on each pole – with big earth mats for single line operation. They can go from power north to power south almost instantaneously. Haywards has both stat and syncons as well as harmonic filters. At the southern terminal, Benmore, they use a running hydro unit(s) to do that.
      It is about 550km on land and 50km long undersea cables (six of them from memory) with the depths going down to 300m or more where there are very strong bottom currents.
      It was mercury arc but now thyristors.
      The problem they have with the DC running north is often not enough reserves and low inertia so unless a big thermal is on, it is limited to about 800MW.
      There are some articles on the Transpower website about it, but you have to ignore the publicity bumpf which is a schoolchild level.
      I am unaware of any good technical articles on it or its operation, though there may be some in IEEE proceedings.

  13. Pingback: New Zealand Grid • Watts Up With That?

  14. Pingback: New Zealand Grid • Watts Up With That? - Lead Right News

  15. David Andrews

    Obviously more energy storage would make everything easier. I didn’t see any mention of energy storage by batteries. Some sizable arrays exist in the US.  Suppose I wanted to make money with a large battery array by charging them when power was cheap ( sun out and wind blowing) and selling power when it was dear.  What battery price/ Gwhr would allow me to succeed?

    • Costs of grid battery including all ancillaries needed is about $1M a MW/MWh. The value of 1 MWh is about $120 average. You can’t do enough daily cycles, even if the power charging it was free, to recoup that investment before batteries have failed.
      For NZ, probably need 5GWh to be credible grid storage. That cost would be more than the value of NZs second biggest power company. If they did really want to have daily storage and reserves, a 300MW pumped hydro at Whakamaru ridge is the best of a lot of uneconomic options. But no-one but the government would build it.

    • David Andrews

      ” No one but the government would build it.”
      You might want to add Elon Musk as someone besides the government who would (and of course already has) built utility scale energy storage with batteries.

      Your numbers are rather pessimistic compared to his. Using his quoted prices, I could buy 1MWhr of storage for $350,000. Using your number: an average price of $120/MWhr, if I did 1 cycle/day I would earn 365 x $120 = $43,800 annually, or a return of 12.5% on my investment. Not bad. The batteries would have a 10 yr warranty, and be recyclable, presumably for credit.

      My impression is that energy storage installation has lagged solar/wind installation, even though we know that the ultimate carbon-free solution will require it. Your discussion shows why.
      The lag may be from an understandable reluctance to buy batteries at today’s prices, since the prices are dropping.

      I am confidant that you can poke holes in my numbers. But if you are trying to predict the future of renewables, you must also predict the future of energy storage. It is a relatively new market, and there are options besides pumped hydro and today’s batteries.

      • Chris Morris

        All the prices I quoted were NZ dollars and came from consent applications. Batteries are typically only half the capital cost. You didn’t include all the stuff like grid connection and your transformers, switchgear, filters etc. Look at the costs of big battery installation in Oz. You need to add the cost of capital to your model, plus the fact you write off the total investment after ten years at most.

  16. I’ve been wondering how I would make my trip to Florida in an EV in 2 days. This has possibilities.×900

  17. Very interesting article for me, as we lived for 5-months in NZ back around 1985. I knew about the natural gas supplies, but forgot about all the hydro. Fished for trout in Lake Taupo once. Do not recall how/if our small home was heated/cooled.

  18. Reality, and political expediency, trump the Green Unicorn, the symbol of the Church of Climate Doomers.

    Last week, numerous media outlets reported that Germany will extend the lives of three of its nuclear power plants. The move to keep the reactors online, which was opposed by the country’s Green Party, showed that German politicians are recognizing the need to keep reliable generation plants online to assure the country has enough electricity this winter.

    But another equally important announcement was also made last week that got far less media attention: German Chancellor Olaf Scholz announced that Germany was reopening five power plants that burn lignite, a low-rank coal. Germany’s return to lignite demonstrates, yet again, the Iron Law of Electricity, which says that people, businesses, and governments will do whatever they have to do to get the electricity they need.

    • This looks like a fake. Just sayin’.

    • OK, according to snopes, which I don’t necessarily trust, it was trashed by high wind.

      • It was just light hearted humor, whether factual or not. I’m going to post the latest debt, deficit and spending numbers next week after release by Treasury. After reading that, we will all need a little comical relief, especially those who think green spending has no ceiling.

      • CK. On economic indicators, the jobs report came out today. The gain in jobs was twice as much as estimated by the “experts”. We hear all this breathless hype about computer models and AI, but then where are the pragmatic results? Do the pundits not use computer models and AI? Perhaps they do! If AI were all it’s cracked up to be, we wouldn’t have these “surprises”. Something, well many things going on these days, stinks.

      • joethenonclimatescientist

        jim2 | October 6, 2023 at 10:15 am |
        CK. On economic indicators, the jobs report came out today. The gain in jobs was twice as much as estimated by the “experts”.

        Jim – What is the over/under on the downward adjustment for Sept that will come out 2-3 months from now. Probably should set up a betting pool – With downward adjustments every month since 2022, we should get some high participation in the betting pool.

      • @joethenonclimatescientist
        Yes, there are post-adjustments to the jobs numbers. In fact, August was adjusted UP! September saw teachers back to work, but that falls far short of the reality twice as much as estimated.

        October has some anomalies. UAW strike for one. But those can be teased out.

  19. This article is one of the best executive level teaching cases I have ever seen – on energy or many related topics. If you break the network in the article into the three major “layers” of any network – Physical layer, Information Flow Layer, and “Mental Model” Layer – it becomes a spectacular model of simplicity and following the flow of nature – that is required for any energy system to be efficient, economical, and environmentally sound. In simple terms, the builders of this network have tried to fit it to natural realities, in bite-size pieces all the way down the chain. This is in stark contrast to networks like trying to fill the California desert with thousands of windmills that are hard to coordinate, and impossible to recycle (because they each contain 30-50 tons of hard to recycle carbon fiber and adhesives). Thank you for wonderful article.

  20. Ireneusz Palmowski

    The polar vortex forecast for October is unfavorable for North America.
    The impact of the geomagnetic field in the north is already apparent.

  21. joethenonclimatescientist

    Chris – more questions for you
    Whats up with that has a post up on offshore projects. Appears that in order to make the offshore projects financially viable, they need revenue of $150 – $200 per Mwh. The post also mentions the average price per mwh for gas plants is approx $50 per Mwh.

    comparing and constrasting with lazard’s LCOE, the offshore cost ranges between $70-$140 per Mwh. while gas generation ranges between $39 and $90 per Mwh. Granted, each operator needs to earn some profit, thus the wholesale price should be 10%-20% above actual costs.

    the question is whether Lazards (an Bloomberg’s ) LCEO is so signficantly different from what is actually occuring in the real world .

    • Chris Morris

      I don’t know why Lazard get their numbers from – Paul Homewood uses audited accounts which show the true cost that are a lot higher. You can lie on a blog post but you better not lie to the Companies Office. There was also a post on Manhattan Contrarian showing the proposed offshore windfarms there are not being built because costs were higher than expected.
      With all the costs quoted for windfarms, that is often only to get it to the disconnector – they don’t measure what are the impacts after that. It is a lot more expensive to integrated into a grid, especially at high penetrations. What can be dispatched if the wind stops blowing? That cost is very high and is the true cost of wind. There are also the transmission lines needed as wind isn’t by the load centres.
      Planning Engineer did at least one post on LCOE. It doesn’t compare apples with apples for wind (or solar) vrs dispatchable power. But stupid people (including politician) get suckered in by the claims.
      Remember Lazard DON’T build power stations or operate grids – they are just venture capitalists – they want investment to occur. If I was a true cynic, I would also say, they want dodgy investments – when those go belly up, there is money to be made in bankruptcy sales.

      • joethenonclimatescientist


        Thanks – you comments are in line with my observations. As an accountant an numbers guy, the advertised numbers dont reconcile with other conflicting data.

        Basic math rule is when you solve an equation, you plug the answer in and work the problem backwards to make sure you get the same answer. One of the reasons I remain dubious of much of climate science is that too many climate science answers, too many climate science conclusions conflict with other known facts. The conclusions promoted by the climate science community for renewables is just one of the most target rich environments for distortions.

  22. ESG was a horrible idea from the start. A very misguided attempt to implement social policy via financial instruments. Another failure of left-wing, control freak governments. People managing money need to focus on one thing and one thing only: making money for clients.

    As Europe embarks on a wholesale review of the world’s biggest ESG investing rulebook, an executive at Deutsche Bank AG’s fund unit says the complete makeover that some in his industry want would be a terrible mistake.

    Dennis Haensel, head of ESG advisory at DWS Group in Frankfurt, said he’s aware that “the frustration level can be very high” among fund managers after years spent trying to adapt to rules that the European Commission now says may not be fit for purpose.

    But if the European Union ends up tossing out major planks of the existing framework, that “would be a nightmare,” he said in an interview.

  23. I would like to hear your comments on Geo-engineering and the impacts of weather modification.

  24. As a postscript/ update, the recent election looks like it will bring a three party rightwing coalition to power (though relative to US politics, they would probably be Clinton Democrats). They generally had less aggressive green agenda policies, though some of the senior people in the smaller parties are very much Net Zero sceptics. Lake Onslow is almost certain to be the first casualty, together with subsidies for EVs. The taxing of tradesmen and farmers’ utes to make Teslas cheaper for urban elites caused a lot of resentment.
    There has been a lot of talk about building offshore wind but no permits, let alone construction, looks likely in the near term. The economics aren’t there. More geothermal seems to continue to be the preferred grid option. Small distribution network hydro are likely to get more support too.
    There was another early morning World Cup quarterfinal the day after the election, but this one was in daylight hours. Many were expecting NZ to lose – they didn’t. The halftime boost to load was only 30MW, less than 1%, but the roads were deserted at was normally a busy time.

  25. This smacks of incompetence. Fusion is difficult enough from a technical standpoint. Incompetent management can be a deal breaker.

    The 35-nation International Thermonuclear Experimental Reactor, or ITER, is seeking to reboot the fusion project after its supply chains were disrupted by war and pandemic. Delays mean ITER’s efforts to harness the mechanics of the Sun’s clean energy on Earth could be overtaken by more nimble startups.

    “What it takes to integrate a facility like ITER and design it from scratch has been lost,” said Pietro Barabaschi, ITER’s director general. “The knowledge is available somewhere but it is not consolidated. We have to get some retired people on board again.”

    • Jim, It rather strikes me as obfuscation, media front-running sour grapes to obscure a certain reality.

      Bloomberg, as with many media elite rags, largely lean towards the statist mindset; it galls them that capitalists are trailblazing a path towards fusion where big government has floundered for decades. While capitalist driven progress still has hurdles to overcome, it has advanced progress where big government(s) have remained stagnant, uninspired for decades.

      • How is ITER, funded by dozens of governments, in any way considered “capitalist driven”?

      • “How is ITER, funded by dozens of governments, in any way considered “capitalist driven”?”

        My point was that the article you present is cover for big government funding. ITER is certainly not capitalist driven, thus their excuses about war, COVID and retirement all stymying ITER fusion efforts; including the lament about being overtaken by nimble capitalists, some not so much “startups”, but nimble nonetheless.

        Not referred to in the article, but Steven Cowley, physics professor and director of the UK’s national Fusion laboratory has pointed out that the current thinking in fusion research is that “bigger is better”. ITER comes to mind doesn’t it? But nimble capitalists seem to disagree. That’s my point.

      • Yes, there are a number of actual capitalist fusion companies. But my water heater is still run by electricity created using fossil fuels. I do hope they succeed making a cheap source of energy.

      • If we’re lucky your electric water heater may be powered by a fusion reactor the size of a shipping container in 20 years, if Lockheed Martin has their way. They’re on the 5th proof of concept reactor. There’s little news, no surprise with Skunkworks running the show, they’ve always been good at stealth.

      • My money is not on Skunkworks reactor, but I don’t know a huge amount about it. I think the closest is Helion, but the best ones are pB11 projects, and my all time favourite is Focus Fusion. There was just recently a big conference for the pB11 projects and they have given themselves the quirky name “PROBONO”. They are also now getting some support from the EU which should speed the pace of progress which has already been increasing exponentially.

        There are dozens and dozens of projects, all in different states of progress. Helion and Focus Fusion aim to have a prototype reactor before the end of the decade and the other projects are not far behind. The fusion part is actually not where the hold up is with many of these projects – people are kind of missing the point with net gain. To date, the small projects are/were trying to show proof of concept and a number of them have moved beyond that. So they start with small reactors which are cheaper and easier to iterate.

        The real challenge is with fast switches and capacitors. The projects that are closest to commercialisation are the “shot” based reactors, and to make usable electricity you need to fire them rapidly. Focus Fusion’s reactor won’t make more energy per shot than about the calorific content of a pistachio (is how they put it), but you can run 1000’s – 100,000s of shots per second. So you need fast switches (one suggestion is to use a type of diamond which switches polarity via a UV laser) and capacitors to shift large amounts of current around in the order of microseconds.

        Their calculations are that the optimum sized reactor is 100 MW with plans for smaller ones initially. And just as Jungeltrunks says, they won’t be bigger than a shipping container. They’ll be about the size of jet engine and produce about the same amount of power.

        Another interesting thing to note, now the pB11 projects are moving on to how to fuel, is Focus Fusion are planning to use decarborane, which is class of compounds that only have boron and hydrogen. Another thing to note from the conference is how much better experimental results have been compared to theory. And these guys are starting to get together to collaborate.

        I’d bet considerable money that someone is going to crack it – commercialisation very soon, and likely before the end of the decade. It’s no longer “20 years away”. The question is who, and will it cause a shift in infrastructure when something better and more efficient might be brewing behind it?

      • Curious George

        If memory serves, the Skunkworks promised a prototype to be unveiled in 5 years, back in 2018(?).

      • “Skunkworks promised a prototype to be unveiled in 5 years, back in 2018(?).”

        Hi George, Skunk Works project lead did suggest it would take about 5 years for Skunk Works to produce a prototype, per their video in the last link that was produced in 2014. Subsequently, in 2017, they indicated the schedule had gotten pushed back to sometime in the mid-2020s. In 2019 they began their 5th generation design, though it’s less than a prototype. There’s little news, the project remains sketchy relative to timelines. While I like Skunk Works optimism, there’s not much news to drive the narrative beyond “promising”. Skunk Works aside, I would say holistically that there’s a great deal of innovation happening to indicate that fusion is within reach in the near-term, my gut says 20 years (pure speculation). I’d defer to Agnostic, who names several others who are developing fusion, he probably knows better than me where the current technological edge is. I share his general optimism though.

  26. Looks like the wind is out of the Green Sails.

    New York’s state government rejected requests from a group of offshore wind energy developers who asked to renegotiate existing contracts amid rising prices and inflation.

    The New York State Public Service Commission (NYSPSC), the state’s main regulator that oversees electric, gas and water utilities, issued the decision late last week, saying it would “preserve the robust competitive bidding process that provides critically needed renewable energy resources to New York.” The energy developers had requested billions of dollars in additional taxpayer funding for four proposed offshore wind projects and 86 onshore green energy projects.

    “The requested amendments to the contracts would have provided adjustments outside the competitive procurement process; such relief is fundamentally inconsistent with long-standing Commission policy,” Commission Chair Rory Christian said in a statement.

  27. Who didn’t see this coming

    “ Ford said customers in North America are unwilling to pay a premium for an EV.
    The company, in turn, is postponing about $12 billion in EV manufacturing investment.
    Ford’s Model e EV unit lost about $3.1 billion through three quarters of this year “

    The left is made up of a bunch of dreamers divorced from realities of free market capitalism. Until we live in a command economy, the customer will decide the future of EVs. There are many inherent challenges to EVs replacing ICEs at scale. The customer rocks.

  28. Is this just the start of more green initiatives biting the dust?

    “Orsted cancels two New Jersey offshore wind projects, takes $4 billion writedown”