Ten Calories Of Energy To Produce One Calorie Of Food

I just read the article  "The Permaculture Solution – an Interview with Warren Brush". It said "Estimates are that the modern agriculture system uses ten calories of energy to produce one calorie of food."

Fearing that I too may be growing negative net energy food. I immediately looked at the energy costs involved with my soil-less gardens. My hydroponic pump uses 160 watts-hours per day or 137.6 KCal or about 576 KJ/day.   Chris Carr was kind enough to remind me that nutritional calories (KCal) are equal to 1000 chemistry calories (cal).    A chemist would probably use Joules and Kilo-Joules (KJ) rather than KCal.   But the we think of food in terms of KCalories rather than Joules, so Ill keep it in KCal also known as large calories as much as I can.  There were other errors in my first draft,  so heres the rewrite.  Many of my calculations will be done using the Energy and Work Unit Conversion at unit-conversion.info/energy.html. 

I did some research and found a daily harvest of 8lbs of lettuce and 100lbs of tomatoes to be respectable averages for a 100sf garden. So I will be using those figures throughout.
Just for grins lets say you irrigate 100 square feet of garden with 10 gallons per day, and you are pumping water from lets say 100 feet below the surface. 

To calculate the power used to pump 10 gallons per minute 100

P_whp = q h sg / 3960

where

P_whp = water horsepower (hp)
q = flow (gal/min)    = (10)
h = head (ft)              = (100)
sg = specific gravity = (1)

P_whp = 10x100/3960 = .2525whp = 0.04497210699688 KCal/sec
This could also be expressed as 188.2892175745  J/sec which is the definition of a Watt.

If you are following along and checking my math you can use the Power Unit Conversion to find the Power.
Power and Energy are different.  Energy is what is delivered and Power is the rate at which it is delivered.
In the above example we deliver 188 Watts for 10 minutes or 31.38 Watt-Hours



We pump for 10 minute so
0.04497210699688 KCal/s  x  600sec = 26.9 KCal
So how many lbs of vegetables would you need to produce 26.9 KCal
Lettuce is 67.37 KCal per lb so you would need 26.9/67.37 = 0.40 lbs of lettuce per day from your 100 sq ft garden. If you harvest 8lbs / day the net gain is 19.97 times
Tomato is 80 KCal per lb so you would need 26.9/80 = 0.34 lbs of tomatoes per day from your 100 sq ft garden  If you harvest 100lbs / day the net gain is 296 times

Below is a list of common vegetables which I got from http://www.freedieting.com/tools/calories_in_vegetables.htm


Lets put this in perspective of a soil-less aquaponic or hydroponic system:
Lets say you use a 20 watt pump 5 hours a day.
    Thats 20 watt-hours x 5 hours/day = 100 Watt-Hours / day  (W-Hr/day)
    Each W-Hr is equal to 0.859845227859  KCal so you spend about 86.0 KCal to pump water each day.

If you grow 8 lbs of lettuce per day on your 100 sq ft aquaponics garden,
8lb/day x 67368 cal/lb = 538944 cal/day or  ,  538.944Kcal/day

You would spend 86.0 KCal to pump water to produce 538.944 KCal of lettuce.
A return of over 6.27 to 1.  Not quite 19.97 times like soil gardening but pretty good!



How about tomatoes...
Lets say you grow 100 lbs of tomatoes per day in your 100 sq ft garden.   
Let also say you use the same amount of electricity - (86.0 KCal/day).
100 lb/day x 80 KCal/lb = 8000 calories/day
So you would spend 86.0 KCal/day to produce 8000 KCal of tomatoes.
A return of over 92 to 1.  Soil gardening was 296 but this is not bad!

Compared to soil gardening the power efficiency is not as good, but water is also a commodity worth preserving and my guess is any of the soil-less methods will beat soil based gardening several times over.   It gets pretty complicated if you consider that some of the water applied to soil returns to the aquifer but ponics are definitely more efficient with water.  

Back to my hydroponic system which consumes 137.6 KCal per day.  It would need to produce 1.72 lbs of tomatoes per day.  But this is just the power used to move water.  Warren Brush was including the power used to make fertilizers, mine, and apply nutrients, and maintain the crop from start to finish.  Thats beyond the data available to me, but at least it still looks like a positive net gain whether you are gardening with soil or without and probably far better than the modern agriculture system using ten calories of energy to produce one calorie of food.

Aquaponics has a side benefit of fish protein which I have not included, but the energy used to make fish food should be considered.  Bioponics on the other hand is free of any further input save iron and magnesium which is also required in aquaponics.


Ill admit this article was difficult for me,  I feel like I have dyslexia where it comes to keeping units straight.  If you find any errors I will correct them, but to my best knowledge I have presented this correctly.

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Water Storage

As water becomes more difficult to obtain we are going to be forced into looking for better solutions.
This is a section of a modular water wall.

I did a quick search and others are also thinking along these lines and some of the walls are very decorative.  The idea of free or cheap drums is admirable but they are not large enough nor are they aesthetic.
 
Its time to think outside the box.  What about large reservoirs of water under our houses or hidden within our walls which would also be used to moderate temperature with its thermo-mass.

I used to live in a very old house in downtown Tucson.  The walls were built of adobe and they were nearly 3 feet thick.  The hot Tucson summers were quite bearable due to the thermo-mass of these walls even though I had no air conditioning.

If we were to build houses like this our energy and water consumption would both drop.  A stucco finish would make the walls look like any other house except for thick walls, and the comfort would be amazing.  This water could be collected during the rainy season and used later in the hot dry summer months to grow food and ensure a beautiful cooling landscape.

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A family of five uses  about 1 acre foot (about 325,000 gallons) or (1225 m³) of water a year.  So saving water from your roof top may only make a small difference, but small differences add up.   Right now it costs about $1000 to process that much water from waste water or to build a new reservoir.  

Desalination has been done in other parts of the world and California is going to build a desalination plant in San Diego capable of 50 million gallons (189000 m³) a day.  But the cost is probably going to be twice the cost we are used to.  There are also concerns that the plant will kill fish, but efforts are being incorporated that should solve this problem.

In total fifteen desalination projects using reverse osmosis are proposed along the coast from Los Angeles to San Francisco Bay.  In the past many other desalination plants have been closed due to the high cost of operation.  The plant will use an enormous amount of energy -- about 38 megawatts, enough to power 28,500 homes.  
The efficiency works out to be about 3 kWh for 1 m³or 88 gallons / kWh fresh water.  Sounds like a lot of water, but the reality is this will only provide about 7 percent of the total water needs of San Diego County.   

Another problem I see is that this is going to be privately owned.  I would prefer to see communities own their own water source.

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Epic adventurer Bread Every day fresh loaf for one

One of the things Id like to be able to enjoy on my planned epic River Murray adventure, is fresh bread.

I can make bread due to a previous enjoyed "Thing", but I cant make a small loaf for one on an open fire. Or at least I couldnt until today.

Every couple of years I get to hang out with two of the most interesting people I know, and at some point each time, we try to make bread on a camp fire.

It almost works a bit.

Sometimes.

Almost.

But not quite.

They tend toward atemptedbread made with chocolate, marshmallows, and M&Ms.

I tend toward trying to talk them out of it.

Sadly, and most enjoyably, neither approach seems to work better than the other.

In fact, I think the only loaf to have worked so far was an M&M/marshmallow concoction that tasted a bit like a bee rolled in flour might.

With this in mind I thought I should try a stack of different approaches to try to make a functional camp loaf for one.

I think I succeeded, and found a half decent way to make a reliable mini-loaf that can be easily made over an open fire.

I started with some salt.

Salt is really, really important. You really cant make bread without it. If you try, what you get is glue.

Im making a small loaf so Im using a small amount of salt.

Exactly one small amount.




I also added a small amount of sugar. Perhaps a 1/4 of a teaspoon.

I add some flour.

Around a third of a cup.

Next time I do this I will try a half a cup, because the loaf didnt quite fill my container.

And some water.

Also around a third of a cup.

And this much dry yeast.

I mixed it with the spoon handle in a way that I thought looked a bit like an automatic bread maker doing its thing.

Basically I gripped the spoon in my fist, and forced the dough around a small bowl in a circular manner until it seemed a bit like dough.







I went with a very wet dough that I would only mix with a stick (in this case a spoon handle) rather than needing to knead. Kneading is way too tricky in a world without kitchen benches, and everything made in a camp kitchen, needs to be made in a single bowl to be practical.

Stir it like crazy, and it will work a treat.

I covered it with some plastic wrap, and waited until it doubled in size.

"Doubled in size" is a thing you hear a lot when youre learning to make bread.









Its a very difficult thing to gauge. In my experence  most people (me included) tend to wait far too long, and end up having their loaf rise way too much. The best way to get the hang of this doubling business, is to leave the dough to rise in a tall thin container. Perhaps something like a spaghetti jar, or a measuring jug.  In a tall thin container, the only way for the dough to go is up, and as a result, its very easy to see when a loaf has doubled in size.

Trying to determine when a loaf has doubled in size in a normal bowl is very hit and miss.

I quite like hit and miss, but if you want a good loaf, use a tall thin container to check the loaf has risen to double its volume before you move to the next step.

Anyway...

After the correct amount of wait, the dough has risen what looks like only a tiny bit.

This tiny bit is really double its original volume.

A cup 1cm wider than a different cup has a MUCH greater volume.

Doubled in volume looks like "a bit wider, and a bit taller"

If you can notice the dough is bigger, its probably doubled.

Next, I rubbed butter all over the surfaces that the dough would come in contact with.

This cooking ... thing is something thats been in my family since I was a toddler.

I dont know what its called, but Im guessing the world knows it as a "waffle iron" or something like that.





Its normal use is to cook stuff between two slices of bread, buttered on the outside to stop sticking and burning.  Fillings include stuff with cheese, cheese, and more cheese.

I added the once risen dough, and searched around for a warm spot to set it for its final rise.

The best spot is always a place that is wasting heat. In my home thats the wireless router.

Its always just lurking there bleeding heat out into the universe.

There always seem to be a lot of wires in the proximity of wireless things. And there always seems to be a lot of wasted heat as well.

Useful heat.



Bread rising heat.

It looked like this when it had doubled in volume again.

Most of the visual doubling is due to my moving the camera closer, but really, this has risen a lot.

Although Its possible I got the photos around the wrong way.

Just remember that doubling in volume doesnt look like much has happened.



If it looks like a lot has happened, its probably too much.

So now its time to cook the thing.

It looked like this after a few minutes.

And this after a few more.













It sounded hollow when it was tapped, so I figured it was probably cooked.

It looked like this when it was cut in half, and it tasted just like bread.

A totally successful method of creating a mini loaf for one on an open fire.

The openness of my un-open fire is obviously something Ill need to deal with, but with a bit of practice, this system will definitely work in the real world on a real open fire.




Im calling this a total success, and over the next few months, Ill be perfecting this method to the point where I can rely on my ability to make a perfect(ish) fresh mini-loaf of bread every day with only minimal effort.

Next time we make camp bread, we might actually get to eat some.

Perhaps now, the haunting, ethereal voice I heard at the last camp, wafting over the bread/chocolate/marshmallow smoke filled site, and endlessly in my nightmares, ...

"Dont pay attention to [Bullwinkle]"
"He knows nothing"
"He doesnt care"

Can finally be put to rest.

The next time I share a camp-site with these young bakers will see real M&M, marshmallow, and chocolate bread, baked in the waffle irons they forced their parents to buy.

It will be a truly great day for bee flavoured bread.




120 Things in 20 years - Reinventing ancient technology again and again in spite

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Making smoked foods Tin can smoker Cold smoke

I thought Id try to get the food to a place where I had a little more control over the temperature. In my first experiment with my tin can smoker, the device was inside the BBQ, and contributed quite a bit of heat. I suspect the BBQ was at around 50c, which is perfect if you want to breed bacteria.

Id prefer not to.

I figured I might be able to create smoke by just dry frying some wood chips, and I think it shows some promise.


I put the can on the wok burner and ran it on high for a bit before adding some hickory wood chips.

In this photo I used a flash so as to not distort how much smoker there was. Its a dull day, and if I took it without the flash, I would have captured half a second of smoke instead of 250th of a second or whatever flashes really run at. [Which is why you cant see much of the flame]

Probably much much faster.


Anyway...

It worked a treat.

A total successful test, and only took about 5 minutes to start smoking, and be ready to use. It might even be possible to just move it inside the BBQ now that its going, and the BBQ heat night keep it going.

That might mean it will be useful as a cold smoke maker, and a hot smoke maker.

I guess I should write some stuff on what smoking is all about instead of jumping right in with a smoker. Sometimes I forget Im supposed to be writing about this stuff, and just get on with the learning.




120 Things in 20 years Making cold smoke in a tin can smoker on a wok burner may just be the 2nd success in a row. Im not sure thats ever happened before.

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