Sustainable Energy New Zealand #4 – Thar’ She Blows! Wind potential in New Zealand

by Oliver Bruce on October 23, 2012

Welcome to the fourth post in the Sustainable Energy without the Hot Air – A New Zealand Perspective series. Today we’ll be crunching the numbers on wind potential in New Zealand. For the background to the work please our introductory post here. Also check out our earlier posts on the potential of hydro power and geothermal. Note: the units are in kWh/day/person – ie. if you ran a 40W lightbulb for 24 hours, it’d take ~1 kWh over the space of a day. We then divide it by person to give you a sense of the scale of the resource proportionate to the size of the population. Be sure to check out the methodology.

New Zealand has significant wind resources with much of the country having average wind speeds in excess of 6m/s. Even with the amount of development since the last report in 2009, we’ve only added around 0.64 kWh/day/person.

Another 1000 turbines (around 2 times the existing capacity) could deliver 4kWh/d/p while a reasonable upper limit (avoiding national parks, settlements, structures, waterways, steep slopes, low wind areas and assuming 50% willingness by landowners) has been calculated at 83kWh/d/p [cntnmby], with 32kWh/d/p available at competitive pricing. 33kWh/d/p would see windmills on 0.6% of total NZ land area, that is, if clustered, an area the size of Stewart Island.

Offshore wind hasn’t been studied seriously because it is twice the price of onshore wind, and thus will not be a viable option in the foreseeable future. Furthermore, most of New Zealand does not have wide shallow sea areas like the North Sea. This restricts opportunities, as wind power gets very expensive in deep water. An approximate estimate of offshore contributions based on shallow water extent might put the potential at 40kWh/d/p.

High altitude wind captured using kites is another bet, but we’ve yet to find a case study of this resource for New Zealand, and the technology for harnessing it is still in its infancy. We’ll assume a capacity of 0 kWh/d/p until proven otherwise.

Summary: There is a pretty substantial resource in wind for New Zealand – it helps that we’re windy and have a relatively low population. We think there is a reasonable argument for around 30 kWh/d/p. Also, it works well that our other main form of renewable power is hydro, as this can be used to balance out the variability of wind.

In the next post: we summarise the potential of wind, hydro and geothermal and discuss the implications of our findings.

Further Reading:

UCSD prof. Tom Murphy of Do The Math assesses the scale of resource in both wind and solar.

Carlos de Castro, a professor of Applied Physics in the University of Valladolid in Spain has written an excellent paper published in the Energy Policy Journal called Global wind power potential: Physical and technological limits. It’s behind a paywall but he wrote a summary of the paper which can be found here. He disputes the overall size of the resource — not so important for New Zealand, but interesting nonetheless.

{ 28 comments… read them below or add one }

noelfuller October 23, 2012 at 11:25 am

Once upon a time, as a boatie, I could count on prolonged calms during winter – a circumstance that has complexities if you are trying to decide what kind of boating to do in winter. However, I have been impressed this year by what appears to be a very high proportion of strong winds and so much rain the water tanks don’t get down more than a few hundred litres before they are refilled. Fruit has been blown off the trees, and branches, while the blossoms have been blown to pieces diminishing the crop, this in urban Auckland.

The point is that global warming raises average wind velocity which wind turbines appreciate except for the extremes. At the same time air density diminishes. A yacht in the tropics may sail easily in 20 knots but would be overpressed with the same amount of sail in rather colder seas.

Surely there are trends to be detected in average wind velocities and in the proportion of calms? So does the effect of rising temperatures enter into calculation about wind power potential?

Noel

John ONeill October 23, 2012 at 5:32 pm

I heard a while back that UK average windspeeds had declined slightly over the last few years, but this study http://ukclimateprojections.defra.gov.uk/media.jsp?mediaid=87845&filetype=pdf
doesn’t project major changes – maybe a bit more wind over Scotland, a bit less in the south.
New Zealand can apparently look forward to more wind and more rain to back it up with. Walter, the wee turbine I helped a mate assemble, had one very lean month this year but has been going like a train lately.

Bob Bingham October 23, 2012 at 5:39 pm

There is a big discrepancy between the rated power of an energy source and its normal output. A good benchmark is a power station like Huntley which is rated at one Gigawatt or 1000 Megawatts.It would commonly have one of its four boilers out of commision for servicing and then not run flat out so say 50% of rated capacity. Wind power is rated at 25 Knots of wind, which is nearly a gale and in practical terms you get about 20% of rated capacity. The best bit about natural energy is that the fuel is free and so after your construction costs you have fixed the price of energy for about 25 years.
In the end you need a good mix of Hydro, Geothermal and Wind to deliver the power we need, when we need it.
Home produced power from roof panels can harness the wealth of the homeowner and produce power where it is needed and delay the huge cost of building a major power plant.

CTG October 23, 2012 at 6:24 pm

A bonus if we go ahead and install that much wind is that andyS will probably emigrate. On the downside, this will probably decrease our wind potential by about 2 kWh/d/p given how much hot air he generates.

bill October 23, 2012 at 10:54 pm

Well, South Australia, at 25% wind and growing, is certainly off-limits!

Oliver Bruce October 23, 2012 at 6:55 pm

Hi Bob,

NZ’s wind capacity factor is between 30-40% depending on the location, so a bit higher than your 20%.

The variability can be balanced with hydro – NZ is one of the few countries with sufficient hydro capacity to manage this on a large scale.

We’ll be summarising wind, hydro and geothermal tomorrow.

Cheers,

Oliver

Doug October 24, 2012 at 12:08 pm

25 knots a mere zephyr here in Wellington ;-)

Thomas October 23, 2012 at 11:18 pm

Great post and with NZ’s electricity sector producing in 2011 a total of 43,138 GWh of electricity or 26.86 kWh/d/p the mentioned 30 kWh/d/p reasonable potential for wind shows what a great resource we got here!

As far as off-shore: I had always dreamed of an ‘energy dam’ road crossing across the Hauraki Gulf from the Kereta Hills near Coromandel to the other side east of Auckland. It would serve to save countless Km of road traffic around the gulf and the associated petrol, offer an opportunity for massive tidal power while protecting the large flat lands of the Hauraki Plains against a century or more of AGW induced sea level rise and provide a service road to a battery of wind turbines along the dam. The sea there is between 20 and 40 m deep and in any case the Hauraki Gulf could be come NZ’s first close to shore wind potential.

Oliver Bruce October 24, 2012 at 12:36 am

Hi Thomas,

We’ll be looking at tidal/marine resources in a few days.

To answer your question re: a Hauraki Gulf tidal barrier – short answer: It’s only got a 2-3 metre tidal range, and there isn’t much water in there. NZ isn’t particularly well suited to tidal lagoon schemes. For comparison, Kaipara Tidal Scheme (bigger harbor, more constrained therefore faster flow, comparable tidal range) will produce around 1.75 kWh/d/p.

It could serve other purposes like making Aucklanders drive to their Coromandel holiday homes shorter (haha!), but in terms of energy generated, it’d be negligible compared to the other options.

I’d do the numbers for Hauraki, but I’m in a rush so they’ll have to wait. The McKay chapter is here though (p82): http://www.inference.phy.cam.ac.uk/sustainable/book/tex/cft.pdf if anyone wants to have a crack.

Oliver

Macro October 24, 2012 at 4:38 pm

‘It could serve other purposes like making Aucklanders drive to their Coromandel holiday homes shorter (haha!)”

I think Thomas will be quite happy for them to stay at home. ;)

Thomas October 24, 2012 at 5:52 pm

Ha! Yes in fact that might be a bonus of not building it… ;-)
I suppose its never gonna happen anyway, but from a size perspective glance at a zoomed out vista on Google Maps seems to have the proposed Hauraki Gulf lagoon if you will at a similar surface area as the Kaipra harbour. Plus if you were to make an artificial barrier you could have a tighter control on the flow and exploit flow density (that’s really what matters) in a controlled manner similar to schemes like this in the Netherlands.

Macro October 24, 2012 at 8:59 pm

Don’t forget the massive mussel farm! (well yes you can actually) ;) Then there’s the hector dolphins, and playing around with the tidal flow might have a detrimental effect on the miranda sea bird flats (godwits etc) – which I gather are already under threat from the farm runoffs, and the silting from the past mining activities.
Mike P could confirm this – but I understand the Firth is a rift valley – so the “lagoon” will eventually become bigger than the Kaipara! :)
I was out on the Firth fishing a few weekends ago – have to catch the tides when you sail from Thames – and we anchored overnight in Te Kouma Harbour – magic! Good snapper too :)
ps Anna S sends her regards :)

Thomas October 24, 2012 at 10:02 pm

Regards back to Anna! Yes the fishing is great in the gulf and sailing perfect. My “Energy Dam” idea is a no-flyer for many reasons you summed up well. However sea level rise will make short work with the current shoreline plus the Hauraki Plains unless we come up with a plan for their defense in one way or another.

This dam concept is just one of these ideas you come up with while driving around the firth to ALK all the while wishing you could take the direct route…

Anyway, NZ is graced with many great things, among them a very high ratio of well exploitable natural and sustainable energy flows per capita. So we should be able as Oliver has so well presented here to have a relatively easy road to a sustainable tomorrow. A highly enviable position really when you compare us to the rest of the globe. :-)

Andrew W October 24, 2012 at 8:01 am
bill November 14, 2012 at 1:07 pm

Well well well – familiar little sleazebag caught out in anti-wind collaboration with equally oleaginous Tories.

andyS November 14, 2012 at 8:29 pm

Great. Any help from any quarter for the anti wind lobby is much appreciated.

Even from the BBC

bill November 15, 2012 at 4:29 pm

Holy Pavlovian Response, BatBeing! I say ‘sleazebag’ and who comes running? Why, it’s Booker’s little friend…

Inicidentally, your other mate, Delingpole, polled precisely 2 votes out of 1500 surveyed before withdrawing his candidacy.

You know, it turns out far fewer people think like you than you’d like to think, andy. Thankfully. As the US election highlighted all-too-clearly…

bill November 15, 2012 at 4:32 pm
bill November 15, 2012 at 4:48 pm
Thomas November 15, 2012 at 8:22 pm

I don’t think this story has much of a potential for an upside for you Andy….

Beaker November 16, 2012 at 3:38 am

Funny isnt it that andyS was fulminating over evidence free corruption allegations against Conservatives Yeo and Gummer, but Heaton-Harris, Lilly, Howell all caught bragging – not a word.
Heaton-Harris is an obvious buffoon, you can see that from what he has written on the subject of wind power and that he thought it a good idea to consort with swivel eyed nuts like Dellingpole.
Still, they are heros to the fervent NIMBYs who admire anyone who can ignore evidence and repeat their claptrap.
Get your andyS bingo cards ready, my marker pen is hovering over ‘birdchoppers’.

andyS November 16, 2012 at 5:50 am

Do you actually think I have any interest whatsoever in this “story”?

[Snip: equally – we have no interest in your bizarre fantasies about the world. GR]

andyS November 16, 2012 at 11:35 am

My bizarre fantasies that invlove the Director General of the BBC… [snipped: are off-topic, and probably unpleasant.]

bill November 17, 2012 at 12:17 am

Look, Mr. Fantasist, you guys really aren’t having a good run lately. That’s because there’s such a huuuuuuuuuuuge – indeed irreconcilable – discrepancy between what you’ve all whipped yourself into a frenzy claiming go to be true (for no better reason than you want it to be true), and actual reality.

Did you take in the bit that the Royal Society for the Protection of Birds doesn’t agree with either the Tory Clown or the Telegraph Clown and their ludicrous, onanistic fantasies about “Bird Choppers”?

And they don’t agree with you, either, do they? You ridiculous little man…

Beaker November 17, 2012 at 4:44 am

When John Hayes claims that Wind Farms have a detrimental effect on Weasels http://www.guardian.co.uk/environment/2012/nov/16/john-hayes-windfarms-gas-nuclear?intcmp=122
does he perhaps mean the impotent apoplexy they arouse in andyS and his NIMBY network?
Seriously, this chump is our junior Sec of State for Energy and Climate Change. He appears to be held in little regard by his senior minister, and has far less responsibility than his predecessor enjoyed. Looks like rival members of the coalition would rather knock lumps out of each other than get on with the serious business of climate change and energy security – and you thought that your ETS was a farce.

Beaker November 16, 2012 at 9:34 am

And when I say Heaton-Harris is an obvious buffoon, its not just that he can not hide it, he actively puts it on show. http://www.guardian.co.uk/environment/2012/nov/15/wind-power-video-tory-mp?intcmp=122
Lilly also caught saying he quite likes wind turbines and owns a house in France surrounded by them. Poor Lilly will be shunned at the GWPF.

bill November 16, 2012 at 12:15 pm

Yep; that’s truly the level of integrity we’ve come to expect from the anti-windbags. Standard Denial – privately well aware that there’s no evidence to support his untenable position, but publicly chumming away with purely invented claims in best Moncktonian manner.

The problem is there is a significant number – but, as noted before, and despite all their considerable noise, not a majority – of dishonest and angry mugwumps who want to be lied to. Right, andy?

bill November 17, 2012 at 12:19 pm

‘No potential upside’ indeed.

Not only did the dreadful Delingpole (a name that should forever stand for any skinny implement used to poke around in sordid recesses, methinks) get a whole 2 votes out of 1500 in pre-polling, in the actual poll the Tories themselves were just creamed, despite their Chancellor’s sleazy intent to evacuate their own policy and turn to saving the world from the windfarm menace as a faux-Populist distraction to his economic incompetence and concomitant attacks on the poor and the social safety net.

“I think you’ll find that [Tory anti-wind apparatchik] Chris [Heaton-Harris] will not be rebelling for a while.”

No kidding! Yet again, Reality 1: Reactionaries 0.

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