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Off-grid house
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adam2
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Joined: 02 Jul 2007
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Location: North Somerset

PostPosted: Sun Mar 11, 2018 3:09 pm    Post subject: Reply with quote

Off course a freezer uses electricity* but my argument is that no ADDITIONAL electricity is consumed by placing in the freezer some ice in addition to the articles already stored.

Therefore I stand by my remark that the energy cost of storing some ice is zero, subject of course to the caveat that it is placed into a freezer that is already in use for other purposes.

*or very exceptionally some other energy source.
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vtsnowedin



Joined: 07 Jan 2011
Posts: 4646
Location: New England ,Chelsea Vermont

PostPosted: Sun Mar 11, 2018 3:38 pm    Post subject: Reply with quote

adam2 wrote:
Off course a freezer uses electricity* but my argument is that no ADDITIONAL electricity is consumed by placing in the freezer some ice in addition to the articles already stored.

Therefore I stand by my remark that the energy cost of storing some ice is zero, subject of course to the caveat that it is placed into a freezer that is already in use for other purposes.

*or very exceptionally some other energy source.

True enough but this is what you said.
Quote:
If you enjoy ice in drinks, make this when power is plentiful. The energy cost of STORING ice is zero, but the energy used in MAKING ice is significant.
.
I don't see the word "additional" there and if it had been there I would not have quibbled with your quote.
Cheers!
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Little John



Joined: 08 Mar 2008
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Location: UK

PostPosted: Sun Mar 11, 2018 9:40 pm    Post subject: Reply with quote

It occurs to me that a full freezer that is regularly used is more efficient, in energy usage, than a relatively empty one (due to less warm air from the outside exchanging with cold air from the inside whenever the door is opened. If that is true, then having a freezer with all empty space filled up with ice will be cheaper to run than having a relatively empty freezer. This, in turn, will presumably offset the large cost of freezing it in the first place.
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clv101
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PostPosted: Sun Mar 11, 2018 9:43 pm    Post subject: Reply with quote

Yep, always better to keep the freezer 'full' if just with containers of water/ice. Not only limits the amount of air exchange, but in event of a prolonged power cut will keep the food frozen much long.
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vtsnowedin



Joined: 07 Jan 2011
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Location: New England ,Chelsea Vermont

PostPosted: Mon Mar 12, 2018 12:25 am    Post subject: Reply with quote

Little John wrote:
It occurs to me that a full freezer that is regularly used is more efficient, in energy usage, than a relatively empty one (due to less warm air from the outside exchanging with cold air from the inside whenever the door is opened. If that is true, then having a freezer with all empty space filled up with ice will be cheaper to run than having a relatively empty freezer. This, in turn, will presumably offset the large cost of freezing it in the first place.
Or you could" here" place your containers of water out on the porch in freezing weather (five months of the year) and stick them in the freezer already frozen thereby avoiding any energy use to freeze them.
But in actual use each weeks or biweekly grocery shop gets added to the top of the chest freezer when it comes in and it or some other occupant gets removed during the next shopping period as needed making room for the next regular shop. I have failed miserably at rotating stock and will probably end up discarding a third of the contents as being too old and freezer burned to consume except in a nuclear emergency.
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Little John



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PostPosted: Mon Mar 12, 2018 1:35 am    Post subject: Reply with quote

I have employed, in the past, a solution to that with a chest freezer. The one I had was just a great big oblong box with no containers. I cut up two square sheets of thin plywood and placed them vertically in the freezer. In doing so, compartmentalising it into three. New stuff went at the far left compartment. Then, as more stuff was purchased, if there was insufficient room in the far left compartment, some of it was migrated to the middle compartment... and so on. I always ate from the furthest compartment to the right that had food in it.

The only thing I had to remember, was to ensure there was a fair mix of food in each compartment, otherwise the system broke down. So, sometimes I kind of broke the rules a bit when placing food in there. But, not too much,
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vtsnowedin



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PostPosted: Mon Mar 12, 2018 2:56 am    Post subject: Reply with quote

My biggest failing is to not clearly label everything as it goes into the freezer. you end up pulling up a plastic bag full of something covered in frost that may or not be what you want for dinner that night. If you are feeling adventurous you thaw out a couple of them and take the best result as your supper. Frozen beets and tofu are not a winner in my opinion.
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kenneal - lagger
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PostPosted: Mon Mar 12, 2018 1:55 pm    Post subject: Reply with quote

I think that we have lost the gist of Adam's original argument which was to put the water in the freezer when there was a surplus of pv produced energy available and use that "surplus" energy to freeze the water so that the "surplus" energy would save energy expenditure at a later date.

Just saying!!
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adam2
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PostPosted: Mon Mar 12, 2018 1:59 pm    Post subject: Reply with quote

Indeed.
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PostPosted: Mon Mar 12, 2018 2:52 pm    Post subject: Reply with quote

Yes Adam was quite correct in that and it did not need further comment. But staying on topic and not drifting off onto new ground would make for a very dull and limited forum.
We are running out of oil!!!
YES!!
When?
Nobody knows!!
We are all going to die!!!?
Yes!
When ?
Before you reach 110!
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Pepperman



Joined: 10 Oct 2010
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PostPosted: Mon Mar 12, 2018 4:35 pm    Post subject: Reply with quote

clv101 wrote:
Pepperman wrote:
Why not go for a low powered DC immersion for late autumn to early spring and then use AC immersions for the rest of the year? In summer you'll have plenty of power left over to run your high power inverter.


Whilst 'on average' there is more excess energy in summer, in practice there are plenty of days even in Dec and Jan when there's excess and days in mid-summer then it's dark and rainy.


Sure but with 6.5kW it would have to be really badly overcast for a long time to trouble you. We have 1kW of PV into 8kWh of lead acid and are frequently overshaded (being on the canals in built up and tree lined areas most of the time) and we almost never use the generator between late March and early October.

It is also possible to use PWM to control immersion heaters. Our Flexmax has a Diversion SSR function which does this. I would imagine you can get standalone PWM controllers that could do the same.
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Pepperman



Joined: 10 Oct 2010
Posts: 770

PostPosted: Mon Mar 19, 2018 8:52 am    Post subject: Reply with quote

You should also be aware that an off grid version of the Zappi EV charger is in the works:

http://myenergi.uk/product/zappi/
https://twitter.com/MyEnergiLTD/status/956976581788033024
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Pepperman



Joined: 10 Oct 2010
Posts: 770

PostPosted: Fri Jun 08, 2018 9:59 am    Post subject: Reply with quote

Even better than the Zappi:

https://twitter.com/Openenergymon/status/1004790030873841665

Open source, just qualified for the OLEV grant and has PV load diversion.

And it's Welsh Smile
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