Thursday 13 June 2024

Giving it the gas [updated]


NZ Electricity Generation, 8:10am to 11:20am, 13 June 2024.
Source: NZ Interactive Electricity Grid by @morganfrnchstgg

Today's a normal kind of cloudy, breezy winter day around the motu (as they say).

As you were enjoying your breakfast toast and coffee this morning, at today's first peak-power time, the electricity grid was supplied with 82% renewable power. Good stuff, right! 

As you can see above (and I've enlarged it for you just below), the bulk of that renewable power came from hydro — almost two-thirds — with a decent amount (17%) from geothermal. Good stuff. Thank you. But can you see the anaemic offering from the other two renewable contributors, solar and wind? Just 129MW from the country's wind farms — contributing just 2% to your breakfast toaster — and from solar just a risible 1.3MW. Virtually zero percent.

And that's a normal morning.  (As we were reminded by Transpower on May 10th, we're so close to being underpowered here that the gap between peak production and consumption on still, cloudy days is dangerously small.) If we zoom out to see the contribution of New Zealand's largest solar "farm" up in Kaitaia over the last seven days, even it's useful-but-insubstantial peak of 20MW is only achieved momentarily in the middle of the day, offering little help for morning or evening peak.  Sure, more solar "farms" are planned, but they all have that same problem. And they all take time to get going. Lots of time.

But what about wind? Sure, this morning it only gave the grid a measly 2%. But on other mornings (Monday for example, see below) wind "farms" put in around 17% of the power that made your shower hot and your kettle boil.

But — and here's the big but — that wind doesn't blow all the time. If we zoom out again to the last seven days (below) we see that the contribution of New Zealand's largest wind farm, just outside Palmerston North, is literally up and down. from zero to 150MW (and back again, see that drop-off on Monday afternoon) in the time it takes to yell "turn that bloody heater on!"

In fairly simple terms, that's why we need gas. Even when the wind does blow and the sun still shines, it's gas that helps make up that sizeable difference. Just one plant, Todd Generation's Junction Road plant running on Taranaki gas produces almost as much peak power as the windmills do on the Tararuas, and at times that the windmills don't, and can't. It's almost like the two are symbiotic. (Just for fun, compare the two graphs above and below, and with the peak morning and evening times at which we need to cook.

Maybe that's why we say, "now we're cooking with gas!"

Even at Huntly — which uses both gas (light brown below) and Indonesian coal(because we're no longer able to produce our own) — and which  produces up to a massive peak of 850MW, you can see it keeping your kettle on the boil even when the wind isn't blowing.

This is why commentators like Alex Epstein describe unreliable wind and solar as "parasitic" on reliable power. And not cheap. Essentially to rely on wind and solar, we need generators to build enough capacity — in the form of power that's easily turned on and off — so that when wind don't blow and sun don't shine the lights can still be kept on. Which essentially means that the more wind and solar are built, exactly the same capacity of reliable power needs to be built to double that, so it can come on the field as a reserve.

But we can't build dams any more — too expensive, takes too damn long under the RMA, and too many objections. And batteries, while promising, still only contribute a maximum of 13MW here, and take oodles of new mining to produce. (And the more unreliables you have, the more expensive battery power would be necessary, one reason this is still is not being tried anywhere.)

So what does that leave? Answer: gas. If you want your breakfast sausages, you need this place to be be cooking – or at least producing power — with gas.

Sure, good old Chloe Swarbrick told the nation on Monday that Australia does all this with domestic solar panels. She didn't tell you however that the price of power in Australia has gone through the roof those solar panels are on. Or how often Victoria, say, suffers brownouts. Or how small a proportion of the grid those panels produce even at peak time. (All of Australia's solar panels, domestic and commercial, contribute just 12% of the grid's power and, like here, need still non-existent battery power and reliable backup generation of the same capacity when they're not producing.) But in any case, New Zealand is not that sunburnt land — not even as sunburnt as Victoria.. And no amount of solar panels can fill the gap when the sun don't shine.

For that, and for some time to come, we still need gas.

(NB: These graphs come from the really neat interactive electricity grid charts made possible by Morgan French-Stagg. Thank you sir.)

UPDATE: The UK has noticed the results of Jacinda Ardern's 'energy suicide note' of banning gas exploration, and warns its politicians not to contemplate the same there. The Telegraph writes:

[UK Labour leader] Keir Starmer is standing by a pledge to ban new drilling in the North Sea, despite New Zealand abandoning a similar policy amid blackout fears. [UK] Labour’s manifesto, due out on Thursday, will feature a pledge to block all new licensing for oil and gas as one of its key energy policies. It follows last weekend’s announcement that New Zealand’s government was lifting a ban on new oil and gas exploration.
    The ban was announced by former prime minister Jacinda Ardern in 2018. “The world has moved on from fossil fuels,” Ardern proclaimed at the time. New Zealand’s trailblazing policy, which was the first of its kind, became a key inspiration for [the UK] Labour Party’s own plan. However, some in the party are now questioning the commitment after New Zealand resources minister Shane Jones last weekend denounced its own ban as a disaster – and revoked it. It followed three years of rising energy prices that have left 110,000 households unable to warm their homes, 19pc of households struggling with bills and 40,000 of them having their power cut off due to unpaid bills, according to Consumer NZ.
    Since April the situation has further deteriorated: Transpower, the equivalent of our National Grid, warned that the nation was at high risk of blackouts. New Zealand’s shift to renewables meant it no longer had the generating power to keep the lights on during the cold spells that mark the Antipodean winter, said Transpower, as it begged consumers to cut their electricity consumption.
    The threat to New Zealand’s energy security comes despite the fact that geologists have discovered billions of cubic metres of natural gas in the seabeds around the country.
    Sean Rush, a leading New Zealand barrister specialising in petroleum licensing law and climate litigation, called the oil and gas ban “economic vandalism at its worst in exchange for virtue signalling at its finest”.... [Shane] Jones said last week: “Natural gas is critical to keeping our lights on and our economy running, especially during peak electricity demand and when generation dips because of more intermittent sources like wind, solar and hydro.” ...
Jenny Stanning, director of external affairs at OEUK, says exploration is essential to simply slowing the decline in output. “The New Zealand experience shows how important it is for countries to carefully manage energy transition and energy security. We will need oil and gas for decades to come so it makes sense to back our own industry rather than ramping up imports from abroad.” ... Russell Borthwick, chief executive of Aberdeen & Grampian Chamber of Commerce – the region that lies at the heart of the UK offshore industry – says the UK needs a managed and nuanced transition to low carbon energy. ... New Zealand’s experience suggests much of the UK industry would not survive a ban on new drilling.
    “Back in 2018, at the time of the ban, there were 20 international and five local companies engaged in exploration and production in New Zealand,” says John Carnegie, chief executive of Energy Resources Aotearoa, the local industry trade body. “Since then, exploration has fallen dramatically. We only have nine remaining investors, seven international and two local. The rest have left.” ...

Robin Allan, chairman of Brindex, which represents the UK’s independent offshore companies, says: “New Zealand’s ban was a politically motivated decision which ignored data on oil and gas demand, the advantages of domestic production and a realistic pace of decarbonisation. The [UK] Labour Party should see what is happening in front of their eyes in another island nation which has already implemented a poorly reasoned policy – and think again.” [Hat tip Ele Ludemann]


MarkT said...

There is another option for handling the peaks - pumped hydro. It only produces around 70% of the energy it needs to pump it up there in the first place, but you can use the excess power from other sources to pump it up there (including the small contribution from wind and solar), and then let the water flow downhill again when you need it. If you use existing lakes and dams such as Lake Onslow it's minimal environmental impact and easier to consent.

Peter Cresswell said...

@MarkT: Indeed. In principle it's a goodie. But gas is a highly concentrated and easily distributed energy source, and gas is here and now. In a more rational world, of course, we'd have both.

PS: from memory, the Onslow scheme was priced at about $16billion plus fuckups, with the usual umpty-tum years until completion (about 2037 or so, at the last most optimistic count, if it were re-started tomorrow). The commitment to it by govt was said to have hindered private investment in alternatives.
Certainly, the last govt's commitment to ending gas and oil was hardly helpful to any kind of substantial investment in reliable generation, and both blue and read team's blancmange alimate policies almost led to the closure of Huntly, which would have been an energy disaster.

MarkT said...
This comment has been removed by the author.
Tom Hunter said...

Good to see you tackling this once more. I did a post back in March over at No Minister, NZ Power Blows where I pivoted off of stuff you had done over a decade ago.

In fact that March is an update from the original post in 2021 because a recently retired Professor of Engineering, Mike Kelly, had just done a report on the goal of an all-electric NZ and while his figures matched my 2021 ones pretty well he went a step further and estimated the cost:

The cost to 2050 will comfortably exceed $550 billion, a workforce comparable in size to the health sector will be required for 30 years, including a doubling of the present number of electrical engineers, and it will need about 10% of the global annual production of lithium, cobalt, neodymium and other materials.

Like so many other aspects of this effort it is almost literally insane.

Chris Morris said...

MarkT is another one who demonstrates they don't understand electricity generation or economics, but he has his mantra to defy facts.
Vacliv Smil summed people like him up.
"There has never been such a depth of scientific illiteracy and basic innumeracy as we see today. Without any physical, chemical, and biological fundamentals, and with equally poor understanding of basic economic forces, it is no wonder that people will believe anything. "

Pumped storage needs cheap surplus power to fill its lake and it generates its income by arbitrage. That surplus power doesn't exist. Water isn't spilled except in floods when it overwhelms generation capacity.
Onslow if built for the quoted price (it would have been a lot more expensive with Snowy 2.0 as the prime example) would have needed to make $1M profit a day every day on arbitrage, just to pay the interest on the loan plus O&M with no capital replacement. At 1200MW and 40% load factor (absolute maximums) That is about $90/MWh. Reality says the load factor is more likely to be around 10% so prices would be quadrupled. Current market price over a year is about $130. So who can build reliable generation to fill the lake at $40/MWh to give the surplus? If someone gives the answer as wind or solar, they prove Smil's comment.

MarkT said...

Chris Morris - As a civil engineerI i think I know something about power generation, and economics. It’s possible there are facts that demonstrate pumped hydro doesn’t stack up, but they’re nowhere to be seen in your rambling and indecipherable comments. To a simplistic mind the fact pumping water up the hill consumes more power than letting it flow down generates might suggest it’s uneconomic, and perhaps that’s the level your thinking is at. But it doesn’t account for the time dependent nature of power demand and the fact there’s times of the day the available supply is stretched, and other times where there’s a surplus. Either you have no idea what you’re talking about, or you do know more than me but can’t convey it clearly and without being an obnoxious wanker.

MarkT said...

PC - Pumped hydro doesn’t necessarily require a 10 year + Lake Onslow type mega project, it could be deployed on a smaller scale on other existing hydro schemes. I agree with the gist of your post though , whatever the merits (or not) of pumped hydro in the medium to long term, we probably need more fossil fuels in the short term as a minimum.

Chris Morris said...

As I happen to be a power station engineer, I think that trumps your knowledge on the subject. I also note that you ignore the fundamental lack of understanding in your previous posts. You demonstrated your ignorance of the subject by writing ". If you use existing lakes and dams such as Lake Onslow it's minimal environmental impact and easier to consent." Onslow in any of its proposed designs was going to drown the existing lakes and dams in about 100m of water.
With regards to your other beliefs, there is no surplus power, they can't build cheap enough plant to make arbitrage worthwhile and the arbitrage fees won't pay off any facilities built, even down at the 1GWh scale.

MarkT said...

Chris Morris - I agree that if you're a power station engineer your technical knowledge on this subject probably trumps mine. But your ability to discuss the matter civilly and calmly, and present your thoughts logically clearly doesn't.

If pumped hydro is folly, you still haven't explained why in the context of varying daily demand, and times of the day where there is surplus. Surely you can't just stop/start the Clutha to meet exact demands, so there must be times of the day there is a surplus?

I also didn't say that Lake Onslow was easy to consent, but easier - compared to say a new Benmore Dam. Lake Onslow is in a locality with minimal population, with no real flora or fauna except for grass, and no redeeming environmental assets. Even less so than Lake Opuha which was built around 30 years ago under the RMA.

So I leave this discussion as I started it, not certain that pumped hydro stacks up, but thinking it might. I am certain though of my concluding sentence in my last post. If you do know what you're talking about, and were attempting to convince me and others with a clear and logical argument, you should consider this attempt an epic fail. I suspect that wasn't your goal though, even assuming you do have the knowledge you claim. More likely an attempt to feel superior for a moment, because you found a topic where you know something that someone else doesn't.

Chris Morris said...

You are talking around without even mentioning the fundamental point because you cannot concede that you don't know. And you have no understanding of even basic economics. Pumped storage does NOT generate electricity. It just stores previously generated electricity at a transactional loss. Now, putting it really simply. Where will the power to fill any pumped storage come from?

MarkT said...

For a moment I suspected you knew what you were talking about but just couldn’t explain it well, and without being an obnoxious wanker. But the more you post the less I think it likely you even do know what you’re talking about. I encounter a similar thing regularly in my own civil engineering space - engineers so entrenched in their own narrow specialist field, and a desire to prove their superiority within it that they can’t see the forest for the trees.

MarkT said...

To answer your question again (even though it was implied in previous responses), from the water flowing over the dam/through the canal or river during times of the day the demand for power is less. Are you able to simply explain a flaw in this?

Chris Morris said...

That abuse is just a sign of your intellectual inadequacy - real teenager behaviour. Just proving you have absolutely no understanding of the subject. You don't even know the difference between energy and power.
I will try to simplify it so that even you should understand.
For any hydro dam, the energy delivered for a flow, expressed in cubic metre days, is fixed assuming none is spilled. Within that interval, the power is adjustable but the energy over the longer time interval isn't. The station varies the power generated by changing the flow rate at that second going through the turbine. If they generate more now, they have to generate less later otherwise they run out of water.
Using a station like Clyde as a practical example, the average flow there is about 500 cumecs. It generates 1MW for every two cumecs. Rather than generate all the time at a steady rate (250MW), it is more beneficial to the grid for them to generate about 400MW between 6am and 10pm, and no electricity (or flow) 10pm to 6am. If they generate more at night for those CMDs, they have less generation during the day.
That is all shown by the graphs which you either didn't bother to read or have the nous to understand. Look at all the Waikato stations.
And that isn't explaining the flaw in your argument -- it shows you neither understand what you are writing about, nor can read graphs.

Chris Morris said...

To make it clearer, a CMD is a volume. A cubic metre per second for a day. 86.4k cubic metres or about 35 Olympic swimming pools. For hydro lakes, their working volume (between consent high and consent low levels) is expressed in CMDs. Then the amount of energy a station can generate is the flow into the lake plus the change in level.

workingman said...


Is another issue that with most hydro in NZ the dams works in series. I think there are 7 main dams/pwer stations on the Waikato river, so the water released from the first is needed to power the 2nd etc. If the first dam simply pumped its water back into its own storage lake then would the 2nd and subsequent dams suffer from lack of supply?

I see the UK is building a new pumped Hydro scheme in Scotland and despite its huge cost and 30GWh capactity will only provide upto 24 hours supply of power for 3 million on windless days.

Chris Morris said...

Yes, they do need to stage the river flows so they have water where needed when its needed. It takes just over two days to get water from Ohakuri to Karapiro so they have to timing the power generated at each station carefully to ensure they don't run out of water when needed. If you were going to pump back up, that would remove the storage capacity of the Waikato lakes even more. They are already tiny.
A more important point is currently the Waikato is run to provide near full load over the peaks and near minimum flow at times of low demand. Typically 8-900MW at the 6 to 9am and 5-8pm. Rest of the time often only Aratiatia and Karapiro generating. NZ needs more reliable MW for those peaks. If one wanted to use the Waikato. That means building more generators into the dams. They could then generate more but for shorter periods. Still up against the CMD limit.
Britain, like Australia, has wasted megabucks on ill-conceived schemes. The unreliables are so "cheap" that they haven't been able to wean themselves off subsidies which the hapless consumer of taxpayer has to pay for. A transfer of wealth from the poor to the rich. Pumped storage may be good for coping with the duck canyon if you have a lot of solar on the grid. Certainly better than batteries and operating in daily energy trading may be a viable financial model if they are having to switch off solar and wind like they do in Oz. Could use that to fill the lakes. Still be more expensive power than out of baseload coal unit or CCGT.