Monday, 13 July 2009

Energy

I live in a smallish town in an old house with a nearly self-sufficient garden... and I have been thinking about how I plan for the future.
I have never been able to disconnect my thinking and planning from the things that I know to be true.  So many things follow logically from a few basic ideas.  

I have been familiar with the first law of thermodynamics for a long time.  It was a topic of discussion when I was a child.  My father used to come up with ideas for "perpetual motion machines."  I'm  still not sure whether he believed in such a thing or whether those theoretical inventions were merely puzzles for me to solve.  They always seemed like puzzles.   One, in particular, took me days to work out....
If energy was stored in a coil spring, and and that spring was dropped into acid to dissolve it, where did that stored energy end up? 
This took me some days of thinking when I was still in primary school.  I decided that the atoms, as they reacted with the acid and "dissolved" would have "shot off" with a speed and direction that was determined by the little bit of the stored energy contained in each one. Those would bump into the other atoms and molecules and "push" them all around.  This should appear as heat... the acid would be slightly heated, not by the exothermic reaction that might be expected by an uncompressed spring,  but a little bit extra, the little bit of stored energy.
I understand that you can't get something for nothing.

In about 1965 (or maybe 1966) when I was at university, studying a number of science subjects, I found it all very exciting that it all fitted together logically.  
Then one little fact was mentioned in passing, during a zoology lecture.... animals all need to live in energy eqilibrium with their environments.  
That means that in order to grow and reproduce, they need to "collect" enough energy for maintenance and growth.  Some hunt, some forage,  and some are opportunistic and inventive. It always comes back to the same problem,  that the amount of energy gained by hunting, foraging must be at least as much as the cost of the activity.  It is the reason that eagles' main diet in the summer is insects, especially grasshoppers when they are available... rather than bigger animals that might fight back.   The cost/benefit to eagles is better.  Energy "in" had to be greater or at least equal to the amount of energy "out."  It is also the reason that honeyeaters have difficulty surviving in cold weather... collecting enough little bits of nectar from flowers is very time consuming and when more is needed (because fo the cold)  life gets hard for honeyeaters.

The piece of information about energy during that zoology lecture included, as an aside, was that the number of calories needed to retrieve a single calorie of energy using modern farming methods is about 40:1!  
This can't continue indefinitely without an unlimited supply of energy.  This is just another application of the first law of thermodynamics...   "you can't get something for nothing."

Humans modified their technology from hunting and gathering to farming when farming became more energetically advantageous.
Agriculture, when it began, was hard work, even when farmers had the use of animal labour. (Though it must have been more energy efficient than hunting and foraging.)  Farmers could produce enough for themselves and a bit more... estimates of about 20% surplus have been calculated.  
This 20% is what was available for taxation and to contribute to the rest of the community, armies, national expansion and eventually cathedrals and monuments to rulers, and so on.  
Empires need to tax more heavily to support their infrastructures and supply routes.  This ends up becoming necessarily political and I don't intend to go into that here.

Here in my own garden, I can easily grow enough food for myself with minimal inputs.  With two of us here, I can do it,  but it is significantly and noticeably harder. When Chris was here, three of us,  it was impossible.  I just can't work hard enough.

Modern agriculture has a small proportion of the population producing food.  The extra energy that farmers need  to produce such a large amount of food using a relatively small amount of human labour,  comes from oil both as diesel in tractors,  and as fertilisers and pesticides that are manufactured using oil.  
Oil has proven to be, not only a very dense and portable form of energy,  but it has also been easily extracted until recent years.   This oil that has been used to supplement our energy input for more than a hundred years was produced by plants and animals that grew millions of years ago... their energy came ultimately from the sun, energy that arrived on the earth over millions of years long ago.  This has meant that humans have been able to retrieve more energy from our means of food production than we have been putting in and apparently getting something for nothing.   The stored solar energy that arrived on earth millions of years ago was like a bank or reservoir that we have been tapping into without replenishing it at all.  It seems only logical that it must run out sooner or later.  In fact, you can't get something for nothing.

In recent years,  since 1970 or so, and Hubbert's calculations, there has been the realisation that not only is the amount of energy limited,  but that enough of it has been consumed that supplies will soon become restricted by that constraint.    There has also been the hope that technology will come to the rescue... it always has before!  But most of that technology that has come to our aid in the past has required energy, eventually speeding up the exhaustion of our inherited  supplies. 

Common sense tells me that whatever the future is like,  it will not be like the last few years. Our way of life will change, and energy consumption will reduce.  
There are two ways that this can happen.  Either it will come about chaotically and perhaps quite suddenly;  or these changes will be managed so that people are able to adapt gradually to the new environment, for that is what it will be.

This has been obvious for many years.  I suppose that is a significant part of my planning for my own future.  I have always tried to learn how to do practical tasks that might, in the future no be done by machine.
My house is more than 150 years old,  and was liveable before electricity was available here, and can be again.
When this house was new, it had about 4 or 5 acres of land around it.  That was necessary for the horse (transport) and cow (milk) and for some fuel also.  There is still a shed with bales for a cow to be tied up and milked.
These days I have a bicycle, though I can also walk to the main street and the shops.  
I have one acre remaining of the original land, and grow enough vegetables for us to live well, and fruit trees getting bigger,  chickens that produce fertiliser and eggs, and the occasional rooster for soup.
I can cut a significant amount of firewood from large trees here.
I have 27,000 litres of water in tanks and that is increasing regularly, as I buy further tanks.  
I support all of my local businesses and I volunteer and work within the community... I think that a community of the size of Kapunda (about 3000) with grain and grazing all around, and a "mediterranean" climate might be a good place to live with a lower supply of electricity.  And it is no accident that I live here.
The oldest part of my house, under repair.... the roof is the original iron with zinc rivets.  The walls were not high enough to have a "break" between the main roof and verandah, as happened in more modern houses when people were more affluent  ie  could build higher walls.
Jonathon and Chris repairing my back verandah roof...
The back of the house with the littlest oldest tank... this one has an overflow into the "house" tank (number 4) and is still plumbed into the kitchen (gravity fed) so that if the electricity is off,  I can still get water with little effort.
The opposite side of the house (under repair)...
Tanks number two and three....
There is so much more to do,  but every bit more makes us more and more self sufficient and less in need of extra energy input...  a work in progress.

PS    I have realised that my plan is to reduce consumption.  While this may work for me,  with advertising encouraging everyone to buy and consume,  perhaps the next step is to reduce production, advertising and selling.  As the economy slows,  this may be happening anyway, though there is still the stimulus package enticing everyone to spend and consume.  This can only make oil and other consumables run out sooner and in the mean time, increase carbon dioxide pollution of the atmosphere.  There is too much stuff.  We need less production and lowered consumption must follow.  

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