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A look into the viability of the future the Government envisages, where an over-supply of renewable energy is captured, stored in hydrogen cells and exported

A look into the viability of the future the Government envisages, where an over-supply of renewable energy is captured, stored in hydrogen cells and exported
Energy and Resources Minister Megan Woods.

The Government wants to position New Zealand as a front-runner rather than a fast-follower on the development of green hydrogen.

Energy and Resources Minister Megan Woods is talking up the benefits of using hydrogen to transfer and store renewable energy.

For New Zealand to reach the Coalition Government’s goal of having 100% renewable electricity by 2035, an over-capacity of renewable energy (hydro, geothermal, wind, solar and biomass) needs to be built.

This is because under this scenario, coal and gas wouldn’t be switched on when demand peaks and/or supply slumps.

So instead of this over-supply of renewable energy going to waste, Woods wants it to be captured in hydrogen cells and either used domestically or exported.

She also sees opportunities for renewable energy capacity to be built specifically for the purpose of fuelling hydrogen.

The Ministry of Business Innovation and Employment (MBIE), in a document released on Monday - A vision for hydrogen in New Zealand: Green paper - detailed the opportunities producing hydrogen presents, as well as the “numerous significant challenges” it poses.

An underlying theme of the paper is that a number of ducks need lining up for hydrogen to meaningfully feature in New Zealand’s energy mix, let alone be an export income earner.

Fuelling hydrogen - 270 new wind turbines (or the equivalent) needed a year

First and foremost, is the issue of ramping up the supply of renewable energy so it can replace fossil fuels (oil, gas and coal).

The Productivity Commission last year estimated electricity generation needed to increase by between 45% and 65% by 2050 for there to be electrification across the economy - IE for electric vehicles to be taken up and the likes of Fonterra to replace its coal and gas boilers with electric ones.

However Transpower, in a 2018 report, estimated that electricity demand as a proportion of total delivered energy demand needed to increase from 25% in 2016 to 61% by 2050:

To meet this demand, it forecast 60 TWh of new generation would be needed. This equates to 4.5 typically-sized, 60-turbine wind farms being built every year from 2025.

In other words 270 new turbines, or capacity to create the same amount of energy, built every year.

Woods on Monday acknowledged these projections, saying the question was how much of this energy should come from wind versus other forms of renewable energy.

The MBIE report showed how the greatest potential capacity lies in wind generation.

Wind currently only makes up 0.83% of New Zealand’s energy supply. Meanwhile solar - another form of energy with lots of potential - makes up 0.07%.

Green hydrogen uneconomic… for now?

Jumping over the initial hurdle of securing renewable energy supply, the question is whether it’s economically viable for it be used to fuel hydrogen.

MBIE noted that globally, 95% of the hydrogen produced is “grey” or “brown”, meaning it’s derived from industrial processes or carbon fuel like gas.

Woods accepted that although the Government isn’t issuing new oil and gas exploration permits, grey or brown hydrogen may need to be produced until renewables are scaled up.

But ultimately, her focus is on “green” hydrogen made from renewables.

MBIE said that as the cost of renewable electricity falls, the cost of producing green hydrogen will drop. It expected new technology, including more advanced electrolysers, as well as economies of scale, to reduce costs.

“Hydrogen currently appears less competitive than direct use of electricity for most applications but should become competitive in some applications, such as 24/7 on-site freight loading operations or meeting energy demands for remote, off-grid locations,” MBIE said.

Potential uses: transport, heat processing, de-carbonising gas

MBIE said there weren’t “significant technical challenges” to using hydrogen as a transport fuel in New Zealand today.

Rather the hurdles were around policy and regulation, economics, infrastructure, hydrogen availability, vehicles, economics and safety.

“Initially the economics will favour converting daily ‘return-to-base’ fleets, public transport fleets or heavy-duty industrial precinct applications such as the current project at the Ports of Auckland,” MBIE said.

A Taranaki-based company - Hiringa Energy - is already working on producing hydrogen to fuel trucks, buses and forklifts.

Its founder, Andrew Clennett told it needs to secure enough demand so it has the economies of scale to really push go with its offering.

This requires regulatory and policy change, as well as public and private sector investment.

In essence, before a trucking company starts replacing its fleet with hydrogen powered trucks that use Clennett's energy, it needs to know the infrastructure is there to support it.

MBIE also explored how hydrogen could be used for industrial process heat - a large source of New Zealand’s emissions.

“Research on future capital costs is limited, although in principle it should be similar to conventional gas boilers,” it said.

“Currently, the total costs of generating heat with hydrogen are significantly higher than with natural gas.”

Another potential use for hydrogen is to blend it with natural gas to make the gas cleaner.

MBIE said this could partially decarbonise heating used in homes and smaller businesses.

Using existing gas pipes and infrastructure could also be a cost-effective way of storing the hydrogen.  

However the International Energy Agency earlier this year noted some safety issues blending hydrogen and gas. It also said this reduced the potency of energy, so more gas would be needed to achieve the same outcome.

The logistics of transporting hydrogen

Another issue to address is transmission and distribution.

MBIE said most hydrogen produced today is used at the same place it’s produced. It can be expensive to transport, but like natural gas, this issue can be overcome by compression or liquefaction.

Hydrogen can also be incorporated into larger molecules like ammonia or methanol that can be transported more easily.

New Zealand already exports methanol and produces ammonia-urea.

While we don’t export ammonia, MBIE said there was a large global market for the fertiliser precursor chemical.

It noted the infrastructure, distribution and handling processes already established to export methanol could be piggy-backed on.

New Zealand and Japan in October signed a Memorandum of Cooperation over working together to develop hydrogen technology.

Accordingly MBIE noted Japan could be New Zealand’s first hydrogen export market, followed by the likes of South Korea - another country in relatively close proximity to New Zealand that has limited renewable energy alternatives and a government interested in hydrogen.

A question of whether it makes sense for NZ to be at the frontier

MBIE once again noted how New Zealand would be a front-runner with a focus on producing green hydrogen:

“There is currently no international market for hydrogen, and no common price. Cost competitiveness of the market depends on the scale, distance from the market and cost of electricity.

“Hydrogen importers may choose to focus on cheaper, brown hydrogen if the drivers behind the hydrogen market do not include emissions reductions.

“Timing of any investment in a hydrogen export market will need to be carefully considered in relation to the development of receiving facilities by importing nations and the securing of purchase agreements in a competitive global commodity market.

“At present there are no identifiable established international supply chains, logistics or infrastructure established, and these may involve significant costs and risks.

“Although there has been some progress in establishing international standards and codes on hydrogen production and transport, these have not been universally accepted or adopted in the energy or transport sectors. Getting international agreement takes time.”

Clennett believed being a geographically small country with an abundance of renewables made New Zealand the perfect place to innovate.

The public has until October 25 to make submissions on the MBIE paper.

We welcome your comments below. If you are not already registered, please register to comment.

Remember we welcome robust, respectful and insightful debate. We don't welcome abusive or defamatory comments and will de-register those repeatedly making such comments. Our current comment policy is here.


This is going to need an amazing amount of capex. Where will it come from??

Especially if we are to be positioned at the bleeding edge of this technology wave.

from fossil fuels :)

  1. Find the nearest mirror.
  2. The personage therein lurking is yer Eventual Capex Provider.

The power companies have enormous free cash flows, currently paid out as dividends in excess of their profits. Perhaps they could be convinced to spend a little money. Quite a few already have wind farm options that are consented but haven't been built yet.

Wholesale electricity: $0.08, average retail electricity: ~$0.28. There is $0.20/kWh that you are paying for grid supply/connection, typically $1-2000 per house per year. With 4% interest rates and 30 year life that can pay for $15-30k of PV system with a lot of excess capacity. From memory you need to install pv with peak output 6-10x your average ~1kW household demand to get through winter. If that means 10-20kW of panels then the modules themselves are only about $5-10k. So once batteries come down in price from $4-600/kWh to $100/kWh (likely in 5-10 years), it will likely become economic for many to go off-grid. Particularly when you can use your autonomous EV for emergency grid-based backup.

Chuckle. You can do it for a lot less than that. We've been off-grid since '04; total system outlay to date; $6,000. Generator fuel started at $1/day, nowadays 30c/day. Bit more efficient than your average house, but.

Is that a generator instead of a PV system?

"" Government’s goal of having 100% renewable electricity by 2035"" - what population growth are they assuming? Haven't all past projections for immigration been under-estimates? OK the new MBIE concept of just sitting on Visa applications has helped keep numbers fairly stable recently but at a severe cost to NZ businesses wanting to employ a critical expert and to Kiwi citizens just wanting their foreign nationality partner to join them.


Minor details. A great way to limit immigration at the moment would be to link it directly to kiwibuild.

That's right; I've heard govt politicians say all they need are more alien building workers to build the needed houses.

Carbon footprint of Kiwibuild houses; their construction and occupants; not mentioned by Govt.Massive, especially if the houses have to be rebuilt every few years in true Auckland style.

Do you mean issue visas according to the number of rooms completed?
Interesting concept.

We are the maddest country in the world, obsesed by get rich quick schemes that involve exporting natural resources.
Fonterra all over again.

If it's powered by wind and sun, then effectively we're exporting wind and sun to be utilised when the buyer needs it.

Oh for goodness sake , how do we export electricity , get real !

Hydrogen as a fule has the great advantage of only producing steam as an emission. Its obvious problems are Hydrogen having the smallest molecules capable of oozing through most materials and the lowest freezing point making it expensive to store. Certainly worth the govt paying for research into ways of storing Hydrogen safely - there are rumours of it being possible to dissolve it into liquid or colloids.

Only advantage hydrogen has as a battery is cheap long term (seasonal) storage, mere cents per kWh, but that only works if the storage vessel is really cheap and that in turn means huge,low pressure, super cold liquid hydrogen. Compressed or storage in other non-fuel mediums is massively too expensive. But liquefaction uses up 30% of the energy it stores making it even less efficient as a battery.

Hydrogen is a terrible, dangerous battery, not suitable for small scale intermittent use (like cars). Only a couple of use cases that make sense: 1/ Ships and large long range supersonic aircraft - both with hydrogen generated by chemical processes powered by nuclear heat. 2/ Seasonal storage of PV energy. But it is likely to be cheaper just to install excess PV to cover winter months.

Even at peak efficiency it takes power to convert water into Hydrogen and that power is not fully recaptured when Hydrogen burns. I read but cannot remember where (maybe that 40% power efficiency was the theoretical maximum. I suppose much depends on what is done with the pure oxygen produced as a by-product of generating the hydrogen.

About as viable as the Hindenburg!!

If you install excess PV to cover winter months then you will end up with a large excess in the summer. This excess could then be used to generate hydrogen and sold for applications where batteries are not viable - shipping, flights, steel making.

There is no benefit in pushing hydrogen for areas that can already be better serviced by electricity. The paper mentions home space heating as an option. This whole process would be use about 10 times more electicity than heating via a heatpump.

In terms of storage, pumped hydro would be better (with an 80% efficiency). The main problem with pumped hydro is needing two large bodies of water (one at the top to pump into and one at the bottom to pump from). NZ's hydro lakes are well suited to this.

NZs hydro lakes are well suited to pumped hydro? Which ones have a large body of water at the bottom to be pumped to the top whenever the wind blows a bit harder? I think you've been drinking the kool-aid.

That is a reasonable idea; create huge surplus of pv in summer and make use of the excess power somehow - steel or aluminum production, plastic and fuel synthesis - perhaps even some hydrogen. Problem is it will be cheaper to do all that stuff, and any hydrogen production in sunnier tropical desert areas with cheaper power and cheaper labour in more highly utilised plants.
In 20 years nuclear will inevitably be a better option for an isolated high latitude country like ours - unless we run an HVDC cable to Oz.

Pumped hydro in the South Island assets?!
You a crazy man. That is not at all what they are suited for.

Maybe subsonic aircraft might be a better usage than supersonic aircraft... the very low energy density of hydrogen makes for a very large challenge on a supersonic aircraft due to the drag penalty due to the large volume needed for the hydrogen fuel. Fineness ratio is your friend with supersonic aircraft. Hydrogen powered aircraft tend to look more like a Guppy than a Concorde...

the low mass of hydrogen (about 3x energy density of hydrocarbons) makes it a fantastic fuel for long distance supersonic as don't need to stop to refuel frequently. A 2x scaled up concorde could fly non-stop from NZ to UK in about 8 hours, Asia or USA in 4-5 hours (only works in huge planes due to lower fuel density). That would have a dramatic impact on NZ's tourist industry, and can be done economically if we just invest in cheap nuclear generated liquid hydrogen.

Where do you store the hydrogen. Yes, by weight it is massively superior to hydrocarbons as it is missing that annoying carbon thingy. By volume it is horrible. Less than one tenth of the volumetric density. Airliners currently fill the majority of the wing volume with fuel. Now I need 3.7 times that volume for the same amount of energy if comparing to Jet A, neglecting the massive thermo annoyances of LH2. I have worked on an LH2 powered aircraft design. There are significant issues with the structural and thermo issues regarding using LH2, nelecting the volumetric issues. Mixing that with the high temperatures of supersonic flight... good luck with that. Far lower chance of success than the promised unmanned taxis that are claimed to be operating in Auckland by 2020. That isn't happening anytime soon.

ESA's Lapcat design of 10 years back showed that could probably do half way round the world at Mach 5. But plane was big. about twice the size of an A380 due to low density fuel (stored in fuselage tanks). It's much more efficient and easier to do at Mach 2.5 - with something like a 2x scaled up Concorde or 3x scaled up Boom Overture (currently in development)

Yeah, right... one was a notional study, the other is hopium. Seriously???

Next thing you will be pushing is a vehicle designed by Moller. .

Also trains


Be nice if the Govt stood by their election promise of severely limiting immigration(and thus energy demand) instead of fantasizing about building (tilting??)enough windmills to make hydrogen for export, transported by gigantic hydrogen powered ships no doubt....

I'd follow what the big guys are working on for example nuclear power station and controlled fusion power.

hydrogen in NZ would be like a good looking building without any foundation.

While I'm a big fan of nuclear energy, our country is basically one big fault line.

She's probably got a fair handle on it, as have commentators above. Hydrogen is not readily transportable, not easily kept, probably good in niche applications. The EROEI (Energy Return on Energy Invested) of most renewables is well below fossil energy, without losing energy in the tranferrence to hydrogen - easy to go negative, I'da though.

But for storing renewable energy I'd be looking at water-at-height. Pumped storage and hydro. Easy technically, robust in action.

not enough elevated land in NZ to do seasonal pumped storage - would need a significant portion of south island high country. Economically impossible, technically difficult and politically unacceptable. Also huge problems with necessary large changes in water level leaving huge wide dusty shores and inducing erosion, hydro-lakes are mostly severely limited in the range of water levels they are allowed to have for this reason.

A note on the viability of SI pumped hydro storage without so much as a mention of the transmission network, demand cycles or HVDC.

But no. Ignore this. Pumped hydro is the way to go!

That's pretty interesting! I stand corrected, it could be technically and economically feasible to do pumped storage for seasonal storage. Though the 70-80m water range is likely to be severely problematic in environmental and safety terms (landslides etc). And it won't be cheap to build 2-3GW of pumped storage. It is also a lot of eggs to store in one earthquake prone basket.

That pumped storage scheme in Central Otago was pushed hard by Brendan Harre on this site some months ago. It was rubbished for both economic and engineering terms. No use rehashing those arguments. It was also put forward to one of the many government committees that was looking at renewable energy. They also dismissed it as it only needs a smidgen of knowledge to see it was not viable.

The EROEI (Energy Return on Energy Invested) of most renewables is well below fossil energy

Is it? This was published in Nature Energy earlier this year and the study estimated that fossil fuels actually had lower energy returned then thought.

They also cautioned about the 'net energy cliff'

This implies that fossil fuel energy-return-on-investment ratios may be much closer to those of renewables than previously expected and that they could decline precipitously in the near future.

the link costs? Yes, fossil energy is lower by the time it gets to the end use, but so is almost everything. The one to remember is that there is a spread of EROEI within fossil oil - high EROEI stuff still coming out of Ghawar while low-grade stuff is coming online from the 'best of the rest'- like fracking and tar-sands and deep offshore.

All very exciting. Wind turbines, really, really big ones, are booming, and getting cheaper and cheaper:
The hub manages the Hornsea 1 wind farm, the biggest offshore cluster on the planet. The array is being erected at a staggering pace, one giant turbine every couple of days. Installation out at sea is lightning fast. “They put up the tower, the nacelle, and blades, in a single day. The team switches it on the next day,” said Matthew Wright, Ørsted’s UK managing-director.
Hornsea 1 began in April and will be finished later this Autumn with 174 turbines providing 1.2 gigawatts (GW), comparable to a large nuclear reactor but built in a fraction of the time. Hornsea 2, 3, and 4, are lined up for the early 2020s. Together they could potentially produce 6.2GW.
The Treasury had originally assumed that offshore wind tenders would come down to £100 per megawatt/hour (MWh) by 2020. In fact the bids fell to £57.50 in the 2017 round. “Offshore wind has outperformed every forecast ever made about the cost curve,” said Mr Wright.
The next round (held up by a legal challenge) should be closer to £50.

Storage is easy too:
Last month the company teamed up with the US energy group Tenaska Power to build four vastly-larger "gigawatt-scale" plants in Texas over the next two years, chiefly intended to back up Texan wind power. This is a revealing venture. Highview is competing toe-to-toe with gas "peaker" plants in a region of the world where pipeline gas is almost given away thanks to shale. If the sums work in Texas, they certainly work in Europe.

Mr Cavada said the levelized costs for a one gigawatt (GW) plant comes in “way below” $100 per MWh. This is already cheaper than any other back-up option on the market, fossil or not. “In ten years from now, I can see that being $50.”

These are remarkable figures. Lazard estimates the levelized costs for gas peaker plants at $152-$206, new pumped-hydro at $152-$198, or a lithium-ion equivalent at $285-$581. Lithium batteries are superb for a few hours but the economics are not viable for utility power over long periods.

The world is changing, for the better.

Wind turbines look pretty good, until you look at their reliability/life. They are sold as 20-30 years of use, but I've seen reports that to date in practice are struggling to get half of that. That wrecks their economics. Possible that the reliability/life problems are or have been fixed, but we won't really know for another 20 years. I think it pays to wait for others to find, fix and pay for the problems.

There has been a really surprising success in offshore wind farms in the UK. I thought it was bonkers, but the engineering problems were rapidly resolved and the technology has improved by leaps and bounds over the last 3 years. The economics have improved as the size has gone up. They are as tall as the taller skycrapers like the Gherkin. Output goes up as a power law to height.

They aren't economic. They harvest subsidies. They get 150 quid for every MWh, which the grid sells for an average of 45 quid. The difference is paid by a tax on power consumers.

This is such a dumb idea.

Convert power to hydrogen in a highly inefficient process.

Then use fossil fuels to transport it around the country.

Then call it green energy.

We have these things call power lines and we have batteries. So you send the power down the line and store surplus in batteries.

If we need more long term storage let’s look at more hydro or pumped hydro.

There isn't anywhere near enough elevated land area for seasonal pumped hydro in NZ, and even if there was it would be politically impossible to do.

We already have a huge amount of hydro, way more than other countries. A bit extra will help to supplement batteries.

“numerous significant challenges” does not capture the magnitude of this folly, it is not a "vision" it is delusion, like the emperor's new clothes.

But the Greens and Labour want to save the world in one term....
Their mangement team is second to none.. Rumor has it that they are going to try and organise an afternoon tea at the Beehive without forming a select committee to complete a two year study into the feasibility of it.

Hydrogen as a carrier isn't a bad idea, just needs to be combined with other elements that make it economically transportable, such as Hydrogen and Nitrogen to make ammonia. Part of the logic behind fuel cell us is the distributed production and storage model. This idea of being an exporter seems to be trying to recycle the business model of the fossil fuel industry, i.e. the idea that someone has a monopoly of the resource - but distributed production and storage of hydrogen and its compounds (especially from renewables) means that no-one will need us to deliver stored energy to them - a frightening prospect for the oil swiggers of the world, I know.

Ammonia is a lethal poison when inhaled.

So is petrol.

And water.

petrol is used by millions in NZ with almost no problems, Ammonia is used by 1000's for a few select industrial and refrigeration applications with stringent safety practices and still causes occasional deaths. Ammonia is probably too much of a safety hazard for widespread consumer use, particularly given high storage pressures and for vehicles that are sometimes parked in confined spaces..

Hydrogen stored at 10,000 psi for transport applications is much more dangerous.
Interesting publication on ammonia storage specs:

From P40 of the Report:

there is no technology currently mature enough to facilitate the low cost, low loss, high volume means that will be required by a hydrogen energy economy, as opposed to those which suffice for the
comparatively modest quantities currently accommodated for industrial use.

So we are looking at blue-sky research into hydrogen, lotsa windmills (sorry, birds....) for the 'renewable' energy, generous Gubmint pump-priming with OPM or loans, and crossed fingers that it all pans out.

Not that this is not perhaps a Worthy Endeavour. But as a Transition, there would be bumps in the road, unexpected costs, elongated timelines as the boffins discover it's Harder Than We Thought, and We the People will wear the eventual costs. At least the Gubmint needs to be Honest aboot That.....

Domestic cats kill an order of magnitude more birds than windmills but are much cuter.

Any bird that cannot avoid those slow turning blades of the large turbines is not a well bird.

The blades are not slow turning. Tip speed is about 300km/h. How good would you be at avoiding a bouncer from a quick bowler which is only half that speed?

Much of the wildlife kill is caused by large pressure gradients in the vicinity of the blades: small creatures cannot withstand collapsed lungs or damaged hearing. Plus the blades quickly get an insect coating, which actually attracts the wildlife via smells. Good summary from Willis Eschenbach, here.

A better, far more workable solution is a trans tasman HVDC cable to bring power from super sunny north west australian PV - no storage needed to give power up to about midnight, and works well through winter due to low latitude. We could send power the other way in the morning. Singapore has a project to get HVDC from same area across 3800km of underwater HVDC.

No need - Central Otago would do it now.

Nowhere near as efficiently, though.
Even accounting for losses, HVDC from northern Queensland would be much more efficient than running another BEN-HAY HVDC if PV was the energy source.

I wonder what the cost balance is between electric trains and hydrogen trains. Sure we can electrify some lines, but it wouldn't make sense to go all the way since hydrogen trains could obviate the need for further capital outlay on overhead lines. There must be some point at which it is no longer viable to go electric... (ignoring the obvious diesel option for argument's sake).

Good post. Yes, electric makes sense in an urban and satellite format, but I don't think hydrogen would fit long-haul. Bio-diesel (despite your brackets :) doing diesel-electric is something we have now.

Batteries and battery swapping for trains makes more sense, much more efficient and safer. Trains have lower power use per tonne-km than trucks so range won't be an issue (Tesla Semi is already demonstrating 800km range)

1. Get one big thing right before taking on the world.
2. Get a plan together for the coming recession.
3. Work on other stuff after that if you are still in office.

Hydrogen. There far bigger countries with a lot more money and brainpower than NZ so doing basic research here is a a waste of time and money. I think there's is some crowd in Taranaki claiming to have some answers on the hydrogen front but need some more money. They may have even been a recipient of Shane Jones's largess. Lot of matchbox calcs going on here as well. Unless in some far off forgotten place or some island that has to use diesel derived electricity. don't waste your money on PV and batteries now unless you have money to throw around and you feel its doing your conscious good. At least 10 years out if not more.

Megan Woods has PhD doesn't she? I assume her staff produced the data in this article and so she is aware and stands behind this data. Exhibit 8 at first puzzled me because we move from a total energy production of 163 TWhr in 2016 to 143 TWhr in 2050. Everything else being equal may be this can be explained by a future high use of electricity in transport where it is 100% efficient compared to the probably less than 25% efficiency transport fossil fuels which we predominantly use now. Plus other efficiency gains.
However at current population growth rates, our population will more than double by 2050. This means that she is saying that our per capita energy use will drop by probably over 57% to 43% of our current per capita use rate. Looks like rubbish to me.
One therefore has to question the reliability of the rest of her material.
Not withstanding that I would prefer to be a fast follower and let other more wealthy and technologically advanced nations take all the risks. These will be the countries who be the manufacturers and sellers of this tech. This will never be us, so I don't see why we should be their guinea pig and pay for their research and development. We are fortunate that we have a lot of renewable energy.
As we adopt more battery power or h2 transport how much can we achieve through automated and highly intelligent management of this load without resorting to wholesale h2 storage. It is a great pity that we have never developed larger hydro storage. There are a few opportunities for hydro storage but the greenies would probably prefer global warming. One thought. Could we bore a few tunnels through the Southern Alps and bleed some of the excess river flows into the Southern storage lakes from the very volatile West Coast rivers. This would have very little environmental impact and achieve larger and far more reliable output from the Southern hydro schemes.
Going back to my first point. Population. It is probably one of the single largest factors and we need to acknowledge this and do something about it instead of adopting the politically correct stance of ignoring it and hoping that it will go away. If you take a big broad look at many of the problems in the world, many of them go back to, or are acerbated by over population. If we keep going the way we are with our population and the resulting pressures, then we may well kill off a large proportion of the population through conflict, disease and or famine. May be this will solve the problem before global warming reaches danger levels. God help us, we don't seem to be learning any other way.

Good post. Indeed, all things are connected, and you cannot address hydrogen without addressing population without addressing consumption without challenging growth. This is a system problem, but we don't seem to be able to muster a systems approach.

We are somewhat squanderous of energy currently, though. A lot is discretionary rather than essential and we'd get healthier from a bit more personally-powered travel.

Ms Woods has a PhD in History. I don't think any of the government ministers got much past School Cert in any science subject.
You don't have to read much stuff put out by governments before you realise that there is not much factual stuff behind them. Just a lot of puff pieces and heroic assumptions. This hydrogen promotion is just the latest one.

@Chris , your remark is well thought through .

Let someone else go through the learning curve of this type of energy substitution , we can avoid some costly mistakes by following

Using surplus (solar) power to cryogenically freeze air and then letting it expand at night to power turbines seems much simpler. Bit like a glorified fridge. Anyway, seems we might have a bit of breathing space climate change wise because of the current lack of sunspot activity, as reported by NASA.

I would like to see the business case for this as I have the sneaky feeling the whole idea is driven by ideology , and without common sense being factored in

You've been here long enough to know that energy underwrites money.

No energy, no work. No work, no debt repaid. (Of course, we've lost sight of that through magic, otherwise known as house price increases).

But given the guaranteed depletion of fossil energy, both volumetrically and quality-wise, we need to have the replacement in place before we can't build it. Waiting is stupidity, in that light.

@PDK Sure , I am not averse to energy substitution , we are in any event reducing our per capita consumption of oil in NZ and I stand to be corrected , but I gather that Huntly and Glenbrook are the only coal -fired power stations still working.

Gas still has a long life ahead , apart from here in NZ where, for now , ideology reigns supreme

I am just concerned we are about to embark on something that simply makes no economic sense , and is unaffordable to the point it bankrupts us as Muldoon did with grandiose schemes

Hmmm - I sometimes reflect on Think Big, Fonterra and the demise of the corner store. Globalism has forced a 'get big or die' on everything, short-term beneficial to the milling crowds in the big-box stores, but long term to their detriment (via no real income). Joe's corner hardware store cannot compete with the byuing-power of Bunnings or M10. Joe gets cheaper spades but is out of work.

So local, small and 'done with pride' are better than 'big and impersonal. So private solar rather than the Clyde High Dam (taking a knapp while the Alpine Fault grinds on?) agreed. The only one I regret the mothballing of, was Motonui

Geez, maybe this Government should focus on the real problems we have staring at us right now, and forget about these Muldoonesque grandiose schemes that will bankrupt us

You mean like removing democracy from Canterbury so cronies can swipe the publicly-owned water, trash the publicly-owned water quality, and reduce the soil quality and biodiversity while relying ever-more heavily on imported inputs?

That kind of grandiose scheme?

At least Muldoon was honest about his intentions and reasons.

I'm not sure if this is a "Think Big" scheme or a "Think Stupid" scheme. Hydrogen is a terrible fuel as it compresses poorly and in fact there are materials that store hydrogen more densely than compressing it by itself. Having a lower explosion limit of 4% by volume it's very dangerous in the event of a leak, especially with the energy release.

While making methanol or ammonia makes more sense due to markets I would want to see the complete chemical process design for all inputs and outputs. The source of the nitrogen and carbon would need to be examined closely.

Often these projects make little or no sense for anyone to attempt this on a commercial scale. There is nothing new in the chemistry, so is this an innovation? Is this even a good idea when operational fusion power plants are so close to becoming a reality. Would this even make sense in a world where there is a new energy abundance?

It may be better to view this as an employment project to prop up the economy during the bad times, or possibly the next Fonterra.

Suggestion to all: instead of torturing electrons on these 'ere threads to vent yer opinions, why not just Submit to the MBIE paper, where real experts and a Gubmint with OPM to burn and loans to raise, can actually Do Somefink (if that's what's to become of all of this)? That way, the latest Think Bigly can at least have had some input....

EDIT: I'm gonna suggest This instead: a bulk purchase of Scalable LIquid Metal–cooled small Modular reactors.

Why are MBIE's numbers so out of alignment with those on Wikipedia? Like 50% out of whack.

MBIE - 163 TWh (2016)
Wikipedia - 258.8 TWh (2017) (931.77 PJ)

When the hydro dams spill excess water, why not run it through the turbines and use that electricity to generate hydrogen and oxygen?

The only excess water spilled is by floods when they have no more turbines left to generate. They report this. So that defeats that idea.

With respect to seasonal and dry-year energy storage buffer, pumped storage would certainly appear a better option than hydrogen storage. The ICCC committee looking into future electrification in New Zealand delegated the task of looking at dry year options to John Culy Consulting - their analysis has been available to the public from July this year:

If the current situation of fossil fuel backup is not to be maintained, the conclusion was reached that "The most promising alternative option appears to be a large pumped storage facility in the South Island". That is, the Onslow scheme. Of course, it was also recognised that further work is essential if it is to be confirmed that Onslow pumped storage is indeed the best option.

The scheme isn't economically or environmentally viable and even a cursory analysis shows that. There is a lot of dead water needed to fill the lake. At the size quoted, it will dewater the Clutha. There will be active slip problems from the raised water levels. It will need a complete new power line from south Otago to Whakamaru. There will need to be a massive overbuild of the windfarms.
But hey, once you have dealt with those problems, you might be on to something.

There is no way that the proposed pumped storage scheme at Onslow could dewater the Clutha. The median flow of the Clutha at Roxburgh is 515 cumecs, and each pump (the proposal is for 10 pump/turbines) would only move 19 cumecs when Onslow is low. For all ten of them to be pumping, it would need to be flooding in all South Island catchments causing wholesale prices to crash.

New power lines would not be needed as the Onslow PSH would be pumping when there is an oversupply of energy in the south, thus reducing load on the lines, and would be generating when there is a lack of generation in the south, and hence able to utilize the existing lines.

The very gentle topography around Lake Onslow would mean no slips, and also allows Onslow to be developed in stages to match the increase in installed wind capacity, rather than lead it.

Thanks for the comments Chris.

With respect to water balance considerations, the simulations in the ICCC Electrification report considered 1000 MW installed capacity, which is less than 150 cumecs for a scheme with minimum upper reservoir operating level of 720 metres. Given a mean Clutha discharge at Roxburgh of 500 cumecs, having storage /release even at maximum rates will neither dewater nor flood the Clutha. Also, the pumped storage flows are buffered by Lake Roxburgh. Pumping will tend to happen when prices are low (higher Clutha discharge) and generating when prices are high (lower Clutha discharge). So the overall effect on Clutha flows will be some increase of lower flows and some decrease of higher flows.

If the scheme went ahead, the initial raising of Lake Onslow would be a long process and filling would be in increments, as is usual with major reservoir fills. During filling there would be a one-off loss of water equating to the volume of dead water to bring Onslow to its new minimum level.

Geotechnical reviews would have be part of the evaluation process. However, it is very unlikely that active slip problems would arise around the lake margins. A drive around the bumpy Onslow roads soon reveals a gentle rock topography – about as good as it gets in terms of slope stability.

The environmental impact would instead be a consequence of a large maximum water level operating range. The Onslow simulation in the ICCC report implied 50 metres operating range. This gives energy storage of 5,000 GWh, more than doubling national energy storage capacity. The 50 metres need only be invoked in extreme dry years, however, and the typical seasonal range would be much less. Seasonal operation could enable Onslow to have a net-positive effect on the grid. We estimate an extra 100 MW from spill reduction on the Waitaki stations, which would be coupled with much-needed reduced seasonal variation of Lakes Pukaki and Tekapo.

As Brendan Harre noted in a previous post, for buffering against South Island dry years there is only a need for a local grid upgrade - not to the North Island. This is because Onslow pumped storage only shifts around the generation locations but the total power going north does not change.

Windfarm development is in no way a prerequisite for the scheme. However, the Onslow scheme would provide some buffer for local wind farm development.

Economic evaluation requires more than a cursory analysis. A starting point would be how much national economic loss could have been avoided if Onslow had been operational before the 1992 and 2008 dry years.

Buffering against South Island dry years would have the added advantage of avoiding burning North Island fossil fuels to send power south. However, a grid upgrade would be required if Onslow is to be used to avoid fossil fuel power generation altogether (in conjunction with wind power development). That would be a national policy decision but the ICCC report indicates that Onslow + grid upgrade is the most economic of a range of expensive options, and certainly better than attempting seasonal hydrogen storage.

The Clutha has a very episodic high flows that distort the mean, it is often down around 200 cumecs. It was less than 250 cumecs this morning. Roxburgh has next to no storage so can't buffer.
If you don't have an overbuild of windpower, where are you going to get the power to pump from? The hydro spill is very little, especially when the lakes are empty.
Brendan is just plain wrong - read the Transpower reports. And think about how the 1000MW is going to get out
The status quo all schemes need to be judged against is a 500MW coal fired power station in the Waikato as hydrofirming.

The long-term Clutha flow mean was only used as indicative that the Clutha was not in danger of being pumped dry by Onslow operation. A flow mean of course says nothing about the location of the quantiles of the discharge-duration curve. And the discharge-duration curve in turn says nothing about the actual time sequence of river flows. We simulated the operation of the Onslow scheme (as if it had been constructed), using half-hour recorded Clutha discharges over the period 1998-2012. All through this time period the simulated options were to (i) pump, (ii), generate, (iii) do nothing. A large number of constraints had to be incorporated – for example, Onslow operation must not move Clutha discharges outside of normal flow variability. It turned out there was no issue with the water balance because in general the times of available energy for pumping coincided with times of higher flow in the Clutha. Similarly, times of energy need coincided with times of low Clutha flow, providing room for water discharged from Onslow generation.

Mention of buffering by Lake Roxburgh was just in the context of short-term pumping/generation to buffer wind speed fluctuations for wind energy. As noted, there is minimal available total storage in Lake Roxburgh.

When hydro lakes are low there will certainly be no spill. However, that corresponds to a dry period with low river discharges (and probably high electricity prices), so Onslow would most likely be generating then and not pumping.

This leads to the energy balance. Suppose Onslow has reached its operating level and is working as part of seasonal storage. Pumping takes place mostly in spring and summer with power derived mainly from the Waitaki stations - they are now generating at greater than normal output because spring/summer water is being released from Lakes Pukaki and Tekapo to maintain their water levels around mid-range. Then in winter when demand is greatest, the Waitaki stations generate less that they did prior because there is little winter water now stored in Tekapo and Pukaki. However, this is counterbalanced by generating from Onslow to make up the required demand. This may seem an inefficient shuffling of water storages because of pump/generation inefficiencies. However, our simulations indicate that maintaining Tekapo and Pukaki near their mid-ranges results in less spill loss because major flood inflows can now be captured by the lakes, and then released for power generation shortly after. Such spills are not common can represent significant lost generation opportunity when they do happen. There is a net time-averaged power gain of something more than 100 MW after subtracting Onslow inefficiencies. That is, Onslow would operate on average in excess of 100% efficiency as a grid entity.

There are other energy source possibilities also. The Roxburgh and Clyde stations are essentially run of the river. So Contact might find it more profitable at times of high Clutha flows and low electricity prices to pump water to Onslow rather than sell the power cheaply or let it spill.
There has to be a one-off increment of energy to get Clutha water into the expanded Lake Onslow in the first place, including the dead water volume. Taking 100 MW continuously from the Waitaki scheme would take less than 8 years of continuous pumping to achieve an operational energy storage of 5,000 GWh. Even that time might be considered too fast for reservoir loading. Perhaps some temporary coal burning in the North Island might also contribute to the one-off energy requirement.

I didn’t mean to imply that I was citing Brendan as an authoritative source – he is an economist? But he is right nonetheless. Get the electrons through to the Benmore node and the transmission line does not care whether an electron comes from Benmore, Clyde, or Onslow. As long as the total number of electrons remain unchanged.

As it happens, the Clutha + Waitaki schemes make a nice water / energy balance with Onslow, taking all installed capacities into account.
All this is with respect to buffering a South Island dry year / winter.

There has also been recent interest in the possibility of Onslow being used to support the national goal of energy transition to green electricity, with all the implications of wind farm developments and transmission upgrades. I don’t have the engineering or economics background to make informed comment on that. However, the ICCC did note that Onslow was the most cost effective means of moving away from gas/coal hydrofirming and it is difficult to see how the desired electrification transition could be buffered without Onlow pumped storage – certainly not with seasonal storage of hydrogen.

Nobody is presently advocating rushing in to build a dam at Onslow. However, the point is made that Onslow pumped storage is worthy of further evaluations in terms of environmental, social, and economic aspects. That seems to be the government view also - an announcement will be made sometime in 2019 of identified agencies who are capable of further investigation into the viability of setting up pumped storage in New Zealand.

You may wish to revisit your assumptions. There are no indications of significant spill for some time.
Many downstream lakes spill because they have machines out on maintenance and they need to maintain the river's flow. That is spilled water but not MWs as there is no way to increase generation. Just like Roxburgh spills when water flow goes over about 800 cumecs. No power to pump.

No obvious assumptions are being made here. There is no suggestion that spill is present in each and every year. The southern South Island swaps between sequences of wetter years and drier years and there will sometimes be sequences of years with no spill. In fact, most years will have no spill at all in the sense of lost generating opportunity. In those years pumping to Onslow will create an energy loss. The point is made, however, that consistently operating the southern hydro lakes and Onslow in the alternative seasonal mode described will produce net power gain as a long-term average. We can’t forecast far in advance when massive hydro lake inflows will happen, but aiming toward having mid-range hydro lake levels throughout the year means there will be space to store those inflows when they happen, however unexpected they may be. Over the period 2009-12 there was high-discharge spill in the Waitaki scheme and about 5,000 GWh of lost generating opportunity, most of which would not have been lost if Onslow pumped storage had been operational at the time.

The Roxburgh and Clyde stations are not so amenable to spill reduction because the Lake Hawea inflows are a relatively small portion of the total Clutha discharge. Nonetheless, pumped storage simulations indicate that shifting Hawea toward mid-range levels would have saved most of the 1000 GWh of lost generating opportunity at Clyde and Roxburgh over 2009-12.

Every cumec of water spilled is lost energy. At Roxburgh it is 2.5 cumecs per MW, and water has been spilled past Roxburgh 3 times so far this year due to high flows. Had Onslow been available then less water would have been spilled as it could have been pumped out of Roxburgh and into Onslow.

With all generators available, Roxburgh passes a nominal 850 cumecs. This varies from 820 to 890 cumecs depending on the head water level. You are correct that water can be spilled when plant is not available, but that is still lost MW and is reported as such. The point you may be missing is that with a pumped storage scheme that some of that water can be stored to be made available at a later time.

You realise that you just repeated bits of the MBIE Hydrogen green paper? Your article doesn't help with coverage of this issue. The issue isn't about what you can reasonable and rationally expect sane and sober people to do wth their own money regarding buying a hydrogen car, investing in 270 wind turbines per year that there is no demand for and no national grid that can handle... The issue isn't about whether any sane engineer would bring forward a project plan to build a hydrogen boat (because you can't buy one). The issue isn't about whether New Zealanders might lose their minds and start to believe that hydrogen stake oil sales man... The real issue is that the government is wasting time and a lot of money and not getting started on the real work of transition to better, lean, smart, clever, elegant, equitable, true green and fantasy free.