[Pil-pc-oceania] Is Burning Wood Really A Long-Term Energy Descent Strategy?

[Joel Meadows]

Dear Russ,
The current situation of coal fired power stations burning coal to  
make electricity gives an energy return of less that 20% of the  
potential energy of the coal, probably a good deal less when true  
distribution losses are accounted for. If we were to match this  
process with wood we would need an inordinate amount of it to get the  
energy out put at our homes that we currently use, even for efficient  
homes.

I would suggest far more efficient wood heaters, ones that triple  
burn and therefore destroy much of the dangerous particulate matter  
are a much better bet. Direct use of energy is usually the best  
approach. It is the same with those Sunlizard, SolarVent unitsi (or  
the variations out there- solar air heaters) they will never be as  
effective as a north facing window of the same size delivering solar  
radiation right inside the house, yet people love another appliance,  
or thing to buy.

It would be great if there were a better rating system for wood  
heaters in Australia showing detailed efficiency and pollutant  
output. The crazy heater/power system (and everything else) that  
appears in Permaculture One might be a bit far fetched, but there is  
no doubt that with some simple engineering we can have vastly more  
efficient wood heaters that your average Coonarra.

The other thing to keep in mind is that densely populated cities are  
unlikely to have the same attraction they have now in an energy  
constrained future.

Joel Meadows
On 19/05/2008, at 8:58 PM, RussGrayson wrote:

> Yes, I found this on Transitionculture too.
>
> The article sates: In a rural situation, where the burning inside a  
> building
> is clean and with a flue, the health effects will be minimal. In a  
> situation
> in a village, town or city it is not so: ambient levels can rise  
> severely
> (for example, in Christchurch, New Zealand, where wood burning is  
> common,
> wintertime levels of particulates can become very high, causing an  
> estimated
> 100 deaths a year and an increase in hospital admissions from  
> respiratory
> complaints by 8%).
>
> It's not only Christchurch. In  a small city where I spent some  
> years -
> Launceston, Tasmania - the situation is the same. There, the city  
> is in a
> bowl of sorts and, in winter, you get a temperature inversion in  
> which a cap
> of dense, cold air forms atop the warmer, lower air. That traps the  
> smoke
> and particulates and they accumulate for sometimes longer than a  
> day. It's
> the same winter phenomenon as occurs in Sydney, which traps the  
> famous cold
> season brown haze over the city.
>
> The article states: An estimated 1.5 to 2 million people die per year
> worldwide from indoor smoke, mostly produced from open and unflued  
> fires in
> the ‘developing’ world.
>
> This I have seen in the Solomon Islands where women cook over a  
> small, open
> fire in a thatched kitchen separate to the house proper.  
> Respiratory disease
> is a common occurrence.
>
> Cannot derivatives be processed from wood and burned in a power  
> station to
> turn existing electricity turbines and supply cities with  
> electrical energy?
> The EROI (energy return on investment of energy) would have to  
> exceed 1:1,
> of course, for efficiency in thermodynamic terms.
>
> ...Russ
>
>
> On 19/05/08 7:38 PM, "harry wykman" <harrybw at iinet.net.au> wrote:
>
>>
>> I received this blog post from Rob Hopkin's Transition Culture,  
>> which,
>> as a student of David Holmgren's when it comes to wood burning, I was
>> troubled by:
>>
>> http://transitionculture.org/2008/05/19/is-burning-wood-really-a- 
>> long-term-ene
>> rgy-descent-strategy/
>>
>> Any responses?
>>
>> Harry
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>
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