Author: Oliver Bruce

Grand final: Sustainable Energy NZ #16 – counting up the dollars and sense

Welcome to the sixteenth and final post in the Sustainable Energy without the Hot Air – A New Zealand Perspective series.

To recap, we started with a bit of energy accounting and worked out that Kiwi’s use around 88 kWh/d/p (methodology for what the kWh/d/p means is here), and that of this, about 33kWh/d/p came from sustainable sources or we couldn’t substitute. As a result, we’ve been looking for how to shift the remaining 55kWh/d/p of our current energy use to renewable energy sources. We approached this in two ways:

How much could we increase our energy generation capacity in renewable sources?

Here, we looked at hydro power, geothermal and wind (and a summary on the big three), solar, biofuels, marine and waste energy and did some basic calculations on the overall potential of these sources. Then:

How much could we achieve a BIG reduction in our personal and national energy consumption, and where those savings would come from.

We went through the areas of energy use for Kiwis, including road, air transport, home energy use and general consumption before doing some calculations on the overall reductions we think we could make.

What might it cost to achieve an all-renewable energy economy?

Today, we’re looking at how this might translate into action at a national level. This post contains both some costing, and suggestions for action that might effectively be channeled into effective change.

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Sustainable Energy NZ #15: Keeping it lean and mean – a summary of energy use.

Welcome to the fiftheenth post in the Sustainable Energy without the Hot Air – A New Zealand Perspective series. After our previous posts on hydro power, geothermal and wind (and a summary on the big three), solar, biofuels, marine and waste energy, we’re now attempting to answer the question:

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

Remember, 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’ve been looking to replace around 55 kWh/d/p of energy currently generated by fossil fuels. Be sure to check out our treatment on road, air transport, home energy use and general consumption from the last few days.

Summary of Energy Use

Using the MacKay categories (but ignoring imported goods and energy spent overseas on air travel), our total energy use of 88kWh/d/p breaks down as shown in Fig.3:

Fig.3  NZ Energy Use (by end use)

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Sustainable Energy NZ #14 – how much energy hides in food and ‘stuff’

Welcome to the fourteenth post in the Sustainable Energy without the Hot Air – A New Zealand Perspective series. After our previous posts on hydro power, geothermal and wind (and a summary on the big three), solar, biofuels, marine and waste energy, we’re now looking at answering the question:

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

Remember, 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’ve been looking to replace around 55 kWh/d/p of energy currently generated by fossil fuels.

Food

Farming and food processing cost about 8kWh/d/p of the NZ energy bill, much of which is of course exported. This is only energy consumed in food production – a great deal more energy is directly incorporated into our food from the sun. When looking at land for either biofuel or solar production, energy production competes directly with food. We could grow a lot more biofuel if we produced a lot less milk, for instance. For the purposes of national energy supply, we doubt much can be gained in terms of energy efficiency to support current production.

New Zealanders eat more beef than the UK population, but we eat next to no grain-fed beef and barning is rare. Overall, the 15kWh/d/p for a UK person is probably pretty similar here. Reduce that to 10 for vegans, but remember that crops cannot be grown on much of the land that we graze (especially not continuously).

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Sustainable Energy NZ #13 – making light work of savings at home

Welcome to the thirteenth post in the Sustainable Energy without the Hot Air – A New Zealand Perspective series. After our previous posts on hydro power, geothermal and wind (and a summary on the big three), solar, biofuels, marine and waste energy, we’re now looking at answering the question:

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

We covered the breakdown of where we use this energy in the last post. Today we’re dealing with commercial and residential building energy use. Be sure to check out our treatment on road and air transport from the last few days.

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’ve been looking to replace around 55 kWh/d/p of energy currently generated by fossil fuels.

Commercial and Residential Energy Use

Making sense of the commercial and residential energy use in the Energy File is more complicated. All the commercial energy to light, heat, and power our gadgets both at home and at work amounts to 21.2kWh/d/p. Compare this with a UK usage of 37kWh/d/p for heating and cooling. A couple of caveats about these figures though. First, “industrial” energy use almost certainly includes some workplace heating, lighting and gadgets, so the real number is certainly higher. The number includes 5kWh/d/p of firewood but excludes firewood obtained from non-commercial sources. Using MacKay’s estimates as a rough guide, we would break this down as follows.

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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), solar, biofuels, marine 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.

Planes

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.

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