Who has experience in "HEATING WITH ICE" ?

[sambotc]

Any ideas on volume required? Also how do you go about storing water underground whilst allowing it to expand when frozen reliably?

 

[bumcrack]

Germ,

I think I understood your concept, but for reasons as stated by others, I can't see it working, so I went off at a tangent!

Your principle starts with a large body of underground water, to all intents uninsulated from ambient ground temperature. In summer you want this body of water to be frozen, so you can slowly thaw it to give chilled water to the house?

All very well, but this water needs to be taken to close to zero for it to be effective for chilling, and you can only do this over winter if you need it frozen for the summer. I don't do GSHP, but as I understand it, the one thing that remains pretty constant throughout the year is ambient ground temps below 1m. Your idea would work to a point, the water could be used for winter GS heating, but it would never get below the ambient of the ground ( 10 deg? ) without further chilling, or massive thermal insulation. As the water descended to ambient ground temps, it would just strip the surrounding ground for heat, I assume this is your principle for winter heating.

But get back to summer, all you have is a body of water at ambient ground temps. You can use this for what? heating!

It seems to my uneducated GSH eyes, your concept is just using water as a heat transfer medium for what is basically GSH, and driving the GSHP is excess PV power in summer. Winter PV excess is minimal if anything, and once you move temperatures beyond either side of ambient, you need energy to do it.

Have I still missed something?, like I say GSH is not my bag!

 

[germ]

Well I seen something on a German website where they were using large sewer sections placed on top of each other on top of a concrete foundation, than they fitted poly pipe which was fixed onto some sort of metal supports in a continuous coil which I suppose was than connected to a heat exchanger.
I remember that it mentioned on the website that due to the layout of the coil, the water would freeze and melt in a controlled manner (possibly from inside out or vice versa) so that the concrete rings would not be exposed to any excessive pressure. I think that this is the tricky thing, working out how to control the pressure when the ice gets unfrozen.

germ

 

[germ]

bumcrack,
I think you're almost there!
I don't want to use the water to cool the house, no!
As you say, the tank is filled with ambient water, which when you try to cool it, will try to extract heat from the surounding ground. Now that is what I want, because we want the water to stay for as long as possible liquid. Once the water is frozen ( because we keep extracting warmth with the heat exchanger out of it) it will try to absorb even more energy out of the surounding ground. This will keep the heat exchanger busy trying to cool the water/ice and by accident it will heat our houses!
Then in spring the ice has extracted a lot of energy (heat) out of the ground so that we will need to help the tank with the excess pv to unthaw again in order to be ready for winter.
This could then be used to cool the house!
Do you understand me now?
regards
germ

 

[Earthstore]

germ, you are correct, you can still pull energy out of ice, ice forms at 0 degrees, however absolute 0 is -273.15 degrees, this is when all the molecules stop moving.
However, as I said before, when your heatsource starts cooling you need to use more energy to extract any heat.

Ice can be stored underground, and it stays frozen, I have seen an icehouse at an old manor house, they used to take ice from the lake in the winter, then use it through the summer.

I understand your train of thought, but I believe you will have to come up with something a little more viable.
back to the drawing board me thinks.

 

[germ]

Any ideas on volume required? Also how do you go about storing water underground whilst allowing it to expand when frozen reliably?

Doesn't water contract when it freezes? I'm just thinking of a milk bottle on the door step. It's only when it unthaws that it expands and bust's the pipe work.
So if you can control the unthawing process you are there!

 

[Earthstore]

No, ice expands but as its a "solid" it doesn't leak, its only when it melts and becomes a liquid it leaks...

 

[bumcrack]

bumcrack,
Once the water is frozen ( because we keep extracting warmth with the heat exchanger out of it) it will try to absorb even more energy out of the surounding ground.

This is the fundamental flaw. Without masses of insulation, and the introduction of chilled water below ground ambient temps, and below zero, you will NEVER freeze the water. As the water gets close to, and below ground ambient, it will just strip heat from the surrounding ground! You could freeze the uninsulated body of water, but the energy input to do this would be massive. Far in excess of overspill from a winter PV plant.

To get water to freeze, you need to introduce it to temperatures BELOW freezing. That means you need chiller plant, and a chiller plant is NOT a GSHP, and does not achieve a posetive overall energy output !

Like I said before, all you have is a GSHP with a layer of water between the coil and the ground.

Find the website, I'm intrigued!

 

[germ]

Have alook at this:

[URL]http://www.youtube.com/watch?v=b0FDSCcMBo8&feature=relmfu
[/URL]

 

[germ]

Apparently when you cool down 1l of water from 80deg to 0deg, you get exactly the same energy as if you transform 1l water into ice at 0deg !
That's pretty amazing, don't you think. Looking at those figures it seems pretty daft to store energy in heating and storing hot water.

germ

 

[bumcrack]

I was off that day we did German.

 

[germ]

Well, I'm sorry about that!
I've had a look in English but the existence of this way of heating doesn't seem to be even acknowledged outside Krautland.
They somehow always seem to be one step ahead, we are just beginning to play with PV, when they've already lost interest in it and have moved on to experiment with ice!
What happened with the old British ingenuity?
Regards
germ

 

[bumcrack]

They have not lost interest with PV, they have reached grid parity.

 

[Earthstore]

It looks like they are using that as a thermal store to ren the heatpump, using a crude solar thermal "grid" to add heat to the store, in addition to that, look at the earth that they have there, it would conduct heat quite well, unlike the "brash" we have around here.

 

[SolarCity]

What happened with the old British ingenuity?

The ingenuity is still there. It's just that Germany is more receptive to ingenuity than Britain is.