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Annie Hope

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since Mar 05, 2012
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Recent posts by Annie Hope

Olive Oil lamps are found in pretty much all Greek Orthodox churches and home icon tables.   Look at the second row on the left.  It shows the wick.  It is a circle of metal with cork ring underneath to make it float.  There is a hole in the middle, and a waxed wick about 1/2 inch long in put in each time it is lit.  

Some Families light the lamp every easter Saturday night at church and keep it burning all year till next easter.  Others just light it at evening prayer and let it burn out overnight.  Particularly in the later case, it is usual to also put water in the glass bowl as well.  When the oil burns to the water level, it sputters itself out.  Otherwise you have the potential to crack the bowl.

I can tell you from experience that olive oil usually burns clean, but a cheap vegetable oil blend does not always do so! We accidentally bought a 4L tin of vegetable oil blend rather than olive oil, and decided to use it in our icon table lamp. Never done so again.  Much cheaper to buy olive oil than to paint the ceiling of the lounge room because it is black above the icon table from burning cheap vegetable oil.
1 week ago
Hi,  I would be interested in picking up this thread and know what you would recommend seven years on factoring the current costs of micro hydros and deep cycle batteries. We have a rise in our property that would probably just be 3m / 10ft high.

I do have on-grid electricity, but will have a separate solar/wind system I will set up myself, and already have 10Kw battery storage capacity we got for a food trailer.  I pay NZ33 cents  (US 24 cents) per KW.

We are starting a home-based food business, so will be doing quite a bit of early morning baking, and so could use this additional storage on a daily basis for this.
2 weeks ago
When I read the research carefully, it gives up to 20X of the power output per squire foot of ground space of the collector, not the square foot of the panels itself.  Tracking in two directions only improves performance by 30-45% compared to a typical fixed array (more in summer as the sun has a few hours in the early morning and evening when it is not hitting the panels at all)    I think the tower would probably get less power per solar panel than a normal flat array.   It is made with the idea that the solar cells themselves are only a small part of the cost of a solar panel now.  the metal surrounds, and then the mounting racks account for the majority of the cost.  My own amateur opinion is that this would be good in one of the following scenarios
- If you are building solar panels from solar cells yourself
-  If you only have a very small space to put them on
-  If you often have cloud cover, and want to pick up the sun whenever you can  

It would be interesting to build one of these and to make flat array with the same number of panels and to test them for efficiency per solar panel area.

What the zig zag pattern does do is pick up the sun for a longer time of the day which is important if it is being direct fed into the grid, but if you are storing it in batteries for overnight use, then this is not an issue - over-all efficiency is.  

What does seem easy to make is something that allows the angle to be changed between ideal summer and winter sun, like this one:
It would only have to be changed a few times each year.  
Because we are on the property through the day anyway, and would use a lot of overnight power in summer (getting up early to cook for a small commercial business, and spray irrigation overnight) it might be worth it to look at building a hand-turnable tower that allows us to get the early morning sun and also allows us to adjust the angle of the panels, but this would take quite a bit of time, and it might be better just to put the money into more battery storage.

I have found this solar panel for half the cost per watt of panels here in NZ, and have ordered one to see the quality before i buy more.  It looks like a good option to build into an adjustable frame:
2 weeks ago

By googling 3d panels rather than zig zag panels, I have found a few commercial samples of them:

I also found this, which looks like the original research done on them that everyone else is quoting:

Fairly heavy reading, but it might give some answers such as what is the best angle to put the panels at.  If anyone finds this interesting, and does wade through the paper and find some answers let me know    

3 weeks ago
UPDATE:  I found this webpage  of commercially made zig zag panels, so there must be something in it.
3 weeks ago

Does anyone have an opinion or any experience with these?  Would they give any more power or are they just the latest scam?  

Even if they don't give much more power  than a conventional 330W solar pane in terms of Watt per $, if they would at least give an equal amount, then they do have the advantage that I am not dealing with panels that are heavier than I am.  Then a few panels could also be taken in summer to use to run fans to vent out green houses to prevent overheating.
3 weeks ago

Thanks for your replies.  I have decided that rather than put bricks directly against the stove I would make a Gabion wall enclave for it.  I already have the wire mesh to do it, and river rocks are free for the taking.  (  this is what are called Gabion walls in NZ)  It will not touch the stove but will hopefully still absorb quite a bit of heat, and should give sufficient protection from the fire heat to the wall behind it.

I have also found someone in NZ that has a 130mm water jacket prototype sitting on the shelf that they will sell me for lest than half the cost of the Australian one.  The first break in the stove pipe is 60cm / 2 feet up.  I was thinking of putting the water jacket above this, and of putting rockwool insulation around the flue below this, as well as putting a piece of rockwool over the stovetop when I am not using it.  Would doing this help  increase the combustion of the stove, and would there be any danger in doing this to the stove?

The burn chamber itself is a 28cm diameter x 35cm high bucket, with a 6 cm diameter hole in the middle of the bottom of the bucket that sits on a 5cm hole through the bottom of the stove (with a damper there).  Then it moves up and sideways under the stovetop to the chimney. The top airflow damper to the chimney on full is 3 x 6cm diameter holes, so the smallest point in the whole system is the 5cm hole at the bottom of the burn chamber.  Because the round lids on the stove top are not sealed, you probably always get a small secondary airflow just before the flue, and could increase this by lifting a lid a bit.

1 month ago
This is a stove we have bought for a greenhouse lean-to.   Its purpose is to heat the greenhouse, provide free cooking, and also to be a back-up to heat water for an underfloor hydronics when there is no sun from DIY solar hot water panels.  I plan to heat water in two ways - a heat exchange coil in a pot on the stove and a water jacket flue like this:  

I have also wondered however, about building a gravel box thermal mass with the water pipes build in.  I have two questions - how hot does a fire need to be for a thermal mass bench to work (ie. draw the smoke down and out)?  Secondly, will the water jacket draw most of the water from the chimney anyway? I also have thought of building a thermal mass of bricks round three sides of the stove box, as I am going to put cement boards  round it anyway to protect the plastic walls  from the fire heat.  I could also catch extra heat from the chimney by putting a sideways u-bend in it above the water jacket before it exits the lean-to.  The top of the lean-to is 3m high, so there is a bit of room.  Would this also slow the flow a bit and give me some more heat in the water jacket?

I also have the frame of a second-hand 300m2 (3000 foot square) greenhouse awaiting the money to have someone help errect it, and the firebricks to build a batch rocketstove inside it and take back to the house, so this is really just a temporary solution to get through winter (which has just started in New Zealand) as our indoor wood stove/boiler cracked a pipe in an earthquake and had to be taken out.  I am expecting that this cook stove may only last a few years of constant use as well.  I am effectively a sole parent on acreage, so time and money is quite limited to experiment, but wood is free for the splitting from rounds.
1 month ago
Hi, It is coming up to winter in New Zealand, and I am trying once again to get my summer outdoor shower with no water storage (240m of coil gives 15m of hot water stored in the coils) to turn into winter underfloor heater with wood stove back-up.  My biggest problem is getting the system to fill with water and say fill of water.  Esp for example when I am trying to pump from the storage tank up over the top and then back down to the underfloor heating.  The pump is not meant to be run dry and won't draw water from dry, but how do you fill the system with water in the first place?  Have tried various ways pouring water in with little success.

I should add that we are 8km from the beach and the minimum winter temperature on record is -4C, and while -2C frosts and ice on puddles are common in winter, the pipes to the water troughs in the paddock have never frozen, so a drain-back capacity is not needed.

The second question is advice about pump sizing.

The underfloor heating will be a little over 300m of pipe in 50 coils, and will need to push back up about 1m to that top of the tank.  

The initial panels are 4 coils with each coil being 1m in diameter, using 60m of pipe, and 25 turns.  (so a total of 240m of pipe, and 100 turns.  These have been flat on the ground, but I want to rise them to about 70 degrees from the ground for maximum winter sun).
I will then also later cover the sun facing wall of a green house that is 1.4m high x 8m long with a bank of black alkathene tubes that are rising.  

2 months ago