Sustainable Energy NZ #12 – do Kiwis have to be flightless?

Welcome to the twelfth post in the Sustainable Energy without the Hot Air – A New Zealand Perspective series. We’ll be changing gears here from our previous posts on hydro power, geothermal and wind (and a summary on the big three), solarbiofuelsmarine and waste energy. From here on out we’ll be attempting to answer the question:

How can we achieve a BIG reduction in our personal and national energy consumption?

It’s a very important topic – and one prone to greenwashing and hype. Like McKay, we want to have informed discussion about the options available to us here in NZ, so we’ll be going through topic by topic and looking at energy use in each sector of our lives: transport, residential energy, the things we buy, and so on. We hope that you find it interesting and informative.

A few notes before we begin: as before, 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. For reference – we’re looking to replace around 55 kWh/d/p of energy currently generated by fossil fuels.


The 2.6kWh/d/p spend on aviation fuel, from the Energy Data File, is a very poor indicator of what New Zealanders actually spend on planes, because of airline fuelling regimes. For example, the return flight from London is included in the UK statistics. Data from the UN [o96d7t] and the International Civil Aviation Authority [8cc3859] gives an estimate of NZ passenger kilometres in 2004.  Dividing by 2004 population converts to 18kWh/d/p using MacKay’s estimate for fuel use. This includes energy spent overseas, and is a better indicator of New Zealanders’ actual energy use on air travel.

To put long distance air travel in perspective:

Return trip to: Energy cost (kWh/d/p)
Europe 56
USA 30 (LA, San Francisco) – 40 (New York)
Sydney 7
Fiji or Vanuatu 8

From an efficiency point of view, a full airliner is as efficient at per person/km as a car with 2 occupants. There is very little room to improve airline efficiency but assuming economic drivers push this to the limit, then perhaps the 2.6kWh/d/p figure, for airline fuel sourced in NZ, could be reduced to 2kWh/d/p.

We should note here that jet travel is one of the ‘big ticket’ items we have control over. One trip to Europe is the equivalent of nearly two thirds of a year of equivalent energy used elsewhere in your life (assuming an overall figure of 88kWh/d/p). The best efficiency option is don’t travel by jet — use videoconferencing instead or get excited about sailing to nearby Pacific islands.

Summary: Air travel is one of the most energy energy intensive activities we Kiwi’s undertake because when we leave our shores, we tend to travel big distances. There isn’t much we can do about it other than reduce our plane travel or consider using alternatives.

Further reading:

McKay’s chapter on planes is a great read for understanding that there are basic physics to how much energy is needed to fly a plane.

30 thoughts on “Sustainable Energy NZ #12 – do Kiwis have to be flightless?”

  1. Air fare prices are dictated by the price of oil, a fabulous fuel, which is becoming scarcer. There will come a time in about ten or twenty years when it will be all over for most of us. How would you get to Europe without air travel? A nuclear powered catamaran passenger boat doing sixty knots would take ten days to get to the UK.
    Something to think about.

  2. A nuclear powered catamaran? A solar powered cat motored round the world not long ago. What’s a little time? A yacht designer I knew came up with a cruising yacht built for less than $3000 (at the time) After he had trialed it for a summer he told me his greatest gain was the aquisition of patience!

    I used to sail about in a 10 metre trimaran. I can confirm the saying among sailors that a yacht is a hole in the sea into which one pours money.I did not have enough. Still there’s a fellow about here who wrote a book about an aviator :)


  3. MS Turanor PlanetSolar , 537 sq metres PV and a fortune in lithium batteries, took 584 days, top speed 14 knots, can accomodate 40 people.
    Ahem who are these people that are in a hurry?


  4. The MS Turanor PlanetSolar didn’t come to New Zealand on its trip – not enough sun down here. However if a nuclear ‘ wing in ground effect vehicle’ had performance similar to the 500 ton Soviet ekranoplan of the eighties, it would make London from Auckland in 25 hours. They were most efficient at 20 metres altitude, so it could go through the Bering Strait and over what’s left of the arctic ice to the North Sea. It would probably do it for a year without refueling, and if you didn’t call it a ship it might not even need a law change! ( The Yanks had contracted a Russian nuclear icebreaker to help resupply McMurdo and Scott Base this summer, which would have been the first carbon free ship in New Zealand waters since the Texas in 1983, but our government pleaded with them to get an oil burner instead.)

  5. Hm…John O Neil…., it moves at 800 km/h at a height of 20 meters, or a faction of a second to impact, above sea level, with a nuclear reactor inside a light weight aluminum/composite skin…. and with currently about 150 to 200 aircraft crashes per year on average,yep, I think that idea will really fly!

    1. The reactor wouldn’t be aluminium. Probably nickel steel six inches thick. There’s a few Russian and American submarine reactors on the sea floor now not causing a problem. Plutonium is insoluble, there’s already millions of tons of uranium dissolved in the ocean, plus radioactive potassium. You’re living on the fragments of a supernova, and since your remote ancestors evolved some ionising radiation has been part of their environment. Your DNA is taking hits from cosmic radiation right now, and repair centres are pulling it in to fix the damage. It’s important not to panic.

      1. Nice John – lets burn that nuclear sacred cow! How about thorium? there’s also some great ideas to use uranium waste products for energy. Unlikely to be economic for NZ, but might cure a blindspot.

        1. Scared cow? Amusing! You will have to burn not just this Physicist (and a significant number of my colleagues) but very likely an overwhelming number of protesters from all walks of life before you would have your nuclear powered aircraft getting a license to operate anywhere outside the Nevada desert….

  6. Your DNA is taking hits from cosmic radiation right now, and repair centres are pulling it in to fix the damage

    …or mis-fix the damage… happens all the time. Those cancers come from somewhere… don’t panic, evolution considers you expendable :-)

  7. Please note that air travel is not particularly inefficient. In terms of kWh/km, 1 person in a car is not as efficient as a 90% full plane. MacKay has interesting numbers on travel by boat – while sea travel is fuel efficient keeping passengers fed, warm and entertained is energy expensive. He has figures from economy trans-Atlantic liners. The real problem is simply the number of kms traveled.

  8. I partly agree with Phil.

    This issue is the number of km traveled at high speed. Reduce the need for speed and you dont have nearly the same issues – except if travelling by sea using fossil fuels. That can easily emit more than flying.

    So the approach should be:

    – First – reduce trips. Air travel for essential trips only. Use internet otherwise and improve greatly the availability and quality of teleconferencing (lots of low hanging fruit and new business possibilities there).

    – Investigate long distance slow alternatives in particular biofueled, solar, wind assisted ships made of latest materials – this technology is much, much easier than retrofitting the air fleet. The ability to work on the move using the internet makes slow business travel a big option now.

    – investigate airships. I dont think anyone has ever flown the Tasman in an airship. Am I wrong? Great opportunity there. Gareth to sponsor with earnings for his book.

    1. When considering the “slow” options (airship included), you also need to look at kWh/d/passenger for heat/cool/light and see that these are at least comparable to home. Options for generating energy on the water are limited and so far very dependent on FF. Crew/passenger ratios (and with it the energy cost) are not favourable on ships. Here for more detail

  9. Well filled aircraft may be more efficient than a car, specially mine. However, I used to read that GHGs emitted at stratospheric altitudes contribute rather more to warming than emissions at low altitudes – don’t seem to have read about that recently.


  10. According to this article
    you would indeed use the same fuel per passenger kilometre in a low , slow piston aircraft. Greenhouse effects should be much less at lower altitude, although the creation of clouds and emissions of sulphur dioxide could partly counteract that. Nitrogen oxides and water vapour at the top of the tropopause raise the level where the atmosphere is emitting heat to space, and since it’s colder up there, less heat is lost; more reflected back down.
    Airships would be even slower, but sorry Gareth, you’re not allowed the helium in case I need it for some of my nuclear contraptions.
    Flying low would reduce background radiation during the flight too, but cancer statistics for aircrew, and for people living in high areas like Colorado, show no effect. Interestingly, while low level whole body radiation from uranium in granite bedrock areas like Cornwall seems harmless, the radon percolating up used to be blamed for about ten percent of lung cancer cases. Revisionist studies have shown that only smokers seem to be involved, which again implies that, when not interfered with, the body’s error correction systems are remarkably good.

    1. Do you have a citation for your assertion that only smokers are affected by lung cancer from radon exposure? I am curious.
      I lived in a granite state for a while. Radon from ground water was a significant issue.

      1. Sorry, it’s a while since I read that and I can’t find it now. Did find a radon cancer victims’ group though, many of whom claimed to never have had much exposure to smoke. From the US Environmental Protection Agency -‘ Radon is responsible for about 21,000 lung cancer deaths every year. About 2,900 of these deaths occur among people who have never smoked.’ They estimate secondhand smoke deaths at about 3000 a year, but I couldn’t find anything correlating radon and second hand smoke effects. Radon decays through a string of Polonium, Bismuth and Lead isotopes, and these bind to smoke or dust particles and are carried deeper into the lung, causing localised beta particle damage over a total half life of about twenty years. So you’re much safer if you’ve never smoked, but ventilate your basement anyway !

        1. Thanks. I studied the matter intently when moving to that granite county in the US in the 90ties. The previous home owner had installed a large permanent carbon filter in his bore water supply. What a hoot! The radon gets attracted to the carbon filter where it decays into a highly active lead isotope, pb-210 with 22 year half life time. This accumulates nicely over many years. When I arrived with my Geiger counter all hell broke loose… and the filter had to be removed under special care at reasonable cost!
          Anyway, this is rather off topic, Apologies

    1. Carol, allow me to expand your travel possibilities , not likely you think?

      You cannot get sick if your stomach muscles remain relaxed, it’s as simple as that if you can do it. I’ve noticed motion sickness is also banished if one maintains a horizon or is on the helm or has responsibility for the way of the vessel.


      1. Thanks for the advice, Noel. My strategy on the inter-island ferry is to sit at the back of the boat, in the fresh air, and keep my head in a book all the way across Cook Strait. I was once taken yachting on the Waitemata Harbour … my bed went up and down for three days afterwards. Unnverving! So, I avoid being on the water as much as I can.
        Is there any chance of solar-powered flight for passenger-carriers?

        1. Indeed yes. Solar Impulse has already made a transatlantic flight and the intention is to fly it round the world. (We don’t count the US military unmanned round the world solar flight ). Then there is the solar Blimp out of Toronto although the US military once again is first in the field. Still if you wish to embark upon such a waka you may be encouraged by remembering that every person in the world is no more than 7 persons away, and often less, by way of personal message from any other person, just ask.

          Of course for a more advanced solar powered vehicle (virtual) this gap may be shortened by consulting with its creator in these very pages – Gareth where are you? :)


            1. Airships as remote-controlled cargo movers sound viable and MacKay calculates them to have similar energy/tonne/km as rail.

              As passenger transport? I would like to see figures for numbers of crew etc to give a base cost per passenger per 1000km. I rather suspect the slow travel would make this rather expensive.

  11. Ah, but folks, the point is you’d never ‘just nip over’ to Hong Kong if you had to drive there, even if such a route existed.

    Efficiency – and I worked out myself that it’s more efficient to fly from Adelaide to Port Lincoln here in SA in a well-filled, low-altitude SAAB passenger turboprop than it is to drive there (check out a map) – is scarcely the point; it’s the deadly lure of convenience and opportunity that’s the real killer with flying.

    And I understand the impact of high-altitude long hauls (i.e. 747s, Airbuses etc.) is a real problem indeed, nearly tripling the CO2 impact alone. If you don’t hear about it much I suspect it’s because most – including on our side – would rather not know!

  12. Phil there is glamour, romance, privelege to consider in getting the rich to pay for development, trips to the international space station for example or great cruise liners that are simply very expensive mobile temples to consumerism. In general it seems that no matter what the mode of transport freight is what pays and keeps the traffic viable – quite obviously looking after passengers and/or crew is expensive compared to just freight and remote control. A quick gallop round airship operators reveals that getting a ride is generally a NO unless there is advertising attached and then only for executives. The precarious existence of passenger trains in NZ well illustrates the point about freight.

    It seems the Naked Bus Blimp was an April fools joke, midway down this page.

    Of interest however, are these graphs on fuel consumption and environmental impact re air transport and blimps.


    1. You’re right. It is expensive and in NY they can’t get it (yet) but..

      This must be the one occasion when “forever” has a known endpoint. It may be that production is not increasing even though demand is, despite new finds. David Archer reckoned that oil is already gone, it’s coal that is the killer. However little is left that is available, it is still way too much, so forever has an end for us. What then? is the question we are addressing now, thanks. Back in the sixties I reckoned that oil was what we need to enable us to develop alternatives, surely governments would see that? Naive I was. I am so glad that people of vision have kept working at it despite everything.

      Of course when the oceans die the anoxic death they have done several times in the past a lot more oil will be layed down


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