News from the Equinox

21 09 2011

Yesterday was the Equinox.  The length of the day and night are equal, and only on the Equinox does the sun rise in the East and set in the West.  Virtually nobody knows this!  From here on, until the next Equinox on March 21, the sun will not shine in our house, bar for the last couple of hours of the day when it skims the South facing windows that are not under the back veranda.  The accuracy with which I have managed to achieve this never ceases to bring a smile to my face, so I thought I would share with you a photo I took inside the kitchen on the 20th of September, the last day any sun comes through our clerestory windows.  That thin sliver of sunlight on the wall is it.  From today, the sun angle is too steep to fit between the eave on the window and the window sill.  We don’t need any more heating, the season is changing and even if it’s 13°C outside, it’s 22ºC inside in the morning, without the AGA running.  We’ve now had a whole week of continuous sunshine, and our water is boiling hot, and the last thing I need right now is to waste precious firewood to create excess hot water.  I used water straight out the hot tap yesterday to make a new batch of beer, didn’t need to burn any gas to sterilise anything.  You DO have to be careful though, you can easily scald yourself when not using a tempering valve, but we are all well trained here….

I’ve been asked how well our new LED lights work, so I took a night photo of the kitchen to share.  Yes, there is flash added here, but really only to reduce contrast, and obviously the lights don’t light up what’s under the table but otherwise it gives you a pretty good idea of how well this works.  The hanging “chinaman’s hat” fittings are great because they reduce the distance the light has to travel, and it’s right above the three working spaces we have, the sink, the stoves, and the table.

I’m very proud of my kitchen, it’s everything I’ve always wanted now the AGA’s going!

The Power of Energy Efficiency

4 09 2011

We recently purchased three new LED globes for the kitchen to test from here.  I was hopeful they would do the job, but they actually perform over and above all expectations.  At about the same time, our power “bill” arrived, and this led me to finally post something about just how efficiently our house runs.  Hardly anyone believes we can run a house “with everything” (except a swimming pool, I draw the line there) on virtually zero energy.  As they say, the proof’s in the pudding, so here is a scanned copy of “the bill”…… (click on the bill for a clearer/enlarged view)

There are two sections to this invoice.  One is the amount of power we consume, and the other is the amount of excess power we generate via the solar power.  As you can see, the Utility states we use 2.5 kWh/day, and we generate an excess of 7.4 kWh/day (in some of the worst solar weather I have ever had to endure – and I sure hope those numbers go up soon).  That we pay only $0.2069 for what we use, and collect $0.5200 for our solar energy certainly helps us in getting an invoice in credit.  But the point lost on many people is that the main reason we have achieved this is because of the strategies we have undertaken to reduce our consumption from some 20 kWh/day 20 years ago, to just 2.5 today.  If you notice that the chart went up from the previous quarter, it’s because we started up a second freezer when we slaughtered our pigs and ran out of freezer space.  I expect that by Christmas we will have it turned off again, especially now we have a going AGA to cook our roasts in….

I have already explained how we reduced our refrigeration cost right down with the “Cool Idea”.  But I haven’t yet disclosed how we heat our water up as successfully as we do.  As far as I am concerned, there is only one way to heat water, and that’s the solar way.  Furthermore, if you do it properly, it is possible to achieve 100% solar fraction (that’s jargon for never boosting!), a little trick I picked up whilst learning all about Renewable Energy at the then Ithaca TAFE in the 90’s.

Basically, you have to tilt the collectors such that they are optimised for winter when the sun is weaker, the days shorter, and the water you want to heat is the coldest.  To calculate the best angle of tilt in the winter, take your latitude, and add 15 to 20 degrees. This will give you the angle from the horizontal at which the panel should be tilted which here on the Sunshine Coast is about 40 degrees.  Then, remove the tank from the roof, and put it inside your house somewhere warm, standing upright.  A vertical tank will not mix cold water with hot anywhere near as much as a horizontal roof mounted one.  Of late, most solar heaters are split systems like this, though most people still install them outside on verandas.

I should also mention the importance of a water saving shower head.  We bought ours twenty years ago when we first started living on tank water, and whilst I doubt it is still available, it is incredibly efficient at under 4 L/minute (about 1 US gallon for Americans).  The less hot water you draw from your tank the less you need to reheat, particularly important in cloudy weather.

You will notice our collectors are on a South facing roof, and as such need to be tilted up on a frame to face the equator at the winter angle.  This has been through destructive winds twice now…… and it hasn’t yet blown away!

To reduce one’s consumption to the level we have certainly requires commitment.  And attitude too.  You often have to spend money up front to make the gains, but I can assure you we are laughing all the way to the bank as the cost of power starts soaring.  I firmly believe that it is only a matter of time before you who read this have to pay the same rate we collect for our solar electricity for the energy you consume.  Will you be able to afford your current wants?

We did two other things in the past 18 months to lower power usage from 4 to 2.5 kWh/day.  One was to replace the 120W PC that used to live here with not one but two laptops.  They are rarely both on at once, but at just 40W each, does it matter?  And then, as digital TV becomes the norm, we replaced our aging 130W CRT TV not with a gigantic plasma screen or similar LED TV, but a same size 23″ LED backlit LCD device that barely uses 30W.  We don’t miss a big screen, because we have never owned one.  And yes I will admit that whenever we see someone else’s  monster TV that can be seen from space, it almost takes your breath away… but then, so do our power bills!

If you have been following this site for a while, you should know we never heat nor cool this house (though of course the AGA will make the place nice and toasty in winter!) because it is passive solar designed – ie the sun shines through into the house all day long in winter, and never in summer.

And those LED lights?  Well they have certainly come a long way, ours look just like an old fashioned incandescent light bulb, except they only consume 5W a pop.  At $20 I know they are not cheap, but they will outlast me with an expected life of 50,000 hours (which at 5 hours a night is over 27 years).  Unlike CFLs (at left), they have no Mercury to ditch in landfill (there are still no recycling facilities around here) and I like them so much I will replace another three as soon as I recover from the AGA Saga!

EDIT:  Since writing this, we have improved our consumption to even lower levels…………

The AGA saga is over

2 09 2011

This post is a continuation of the AGA Saga almost over

The beast is conquered…..  After 15 years in waiting, the AGA is finally ready for firing up.  The flue went in Monday, (those struts that support the flue above the roof I found at the tip a few weeks ago… perfect for the job too, nice and strong, and just the right length).  I got all the plumbing fittings to connect the wetback to the hot water system Tuesday, and today I generally stuffed around soldering all the one inch bits that have to be connected to the stove itself.  Research on the ‘net clearly said to not fire it up without doing this first otherwise the boiler might burn out  Those big copper pipes almost make the whole thing look like a big still!

Plumbing the wetback was a saga in itself…. one inch pipes and fittings are one order of magnitude dearer than 1/2 inch plumbing, and just bending those pipes was an effort which unfortunately did not come out perfectly as I wanted.  And of course it all had to fit in with the split system solar water heating, which meant doing a fair bit of re-plumbing there as well….  But there you go, the stove is sixty years old, and it’s showing its age with chips in the enamel, a broken dome that I have yet to work out what to do with, and still no grilles for the ovens where the important cooking is done.  So whilst the hard work has been done, there are still things to fix, and more money to be spent.  Such is life……..  The boiler will now give us unlimited hot water, rain hail or shine.

I’m particularly pleased with this project though, as Glenda thinks she remembers Richard once telling her before he died that the cooker was beyond repair.  Or maybe it was going to cost an arm and a leg to fix it.  There’s nothing quite as satisfying as bringing a nice piece of hardware like that back from the brink.  I hope Richard is watching from wherever he may be.


Yes….  I fired it up.  With trepidation, I filled the void called the firebox with paper, kindling, and a few pieces of leftover pine from building, and lit a huge ball of scrunched up newspaper in the ash pit below the firebox with my BBQ lighter.  It was very smoky to start with (as per instructions, the auxiliary vent pipe was blocked off), and smoke even came out of interstices I didn’t know existed but eventually the smoke disappeared, and now a nice clean combustion is happening.  The new flue draws beautifully.  I’ve topped it up with hardwood now, and combustion has slowed nicely.

In fact, it is working beyond all expectations.  I have done a lot of research on AGAs on the internet, and everyone was telling me you could not burn firewood in an AGA, that the calorific content of wood was so much lower than fossil fuels it simply would not work….  I also read it takes an AGA 12 to 18 hours to “reach temperature” (they are known as heat storage units rather than merely “stoves”), well I am happy to report that this AGA reached temperature in less than three hours…  In fact, it’s now just three hours ago I started the fire and I already have turned the thermostat to the lowest setting of 1.  It’s making oodles of hot water, warming the kitchen up far more than I had anticipated, and we have already boiled our first kettle on it in no time flat.  All the research I have done on the internet bar none says that AGAs should never be turned off, except perhaps in Summer, because they take so long to heat up.  After this first experience with my wood fired cooker, I reckon I will be able to start it up at will, particularly in Winter when the occasional rainy period starts to make our solar water heating marginal, or if the weather turns really cold in those westerlies….

Success is soooo sweet.  Must be time for a pint of Guinness!

PS.  For info on AGA wood conversion kits look here

Inadvertently, I discovered that there is an AGA shop in Melbourne (where of course you cannot buy the now long Cream Roomset 2discontinued solid fuel version capable of wood conversion we have), and the price tag for a new cooker blew me away……

Prices inc. GST


2 Oven Classic Cooker $21,207


2 Oven Classic Cooker $24,013


2 Oven Classic Cooker $23,486