Maximizing Heat Storage in Water: Photovoltaic vs Radiator

[camerart]

Hi,
I'm going to make a comparison test between Photovoltaic solar panels and the radiator type.

I intend to store all heat with an insulated water tank.

Many years ago, I heard about water bottles in a green house with some kind of salts in the water, which allowed the water to store more heat than plain water. I'm not talking about raising the boiling point!
Any ideas as to what this salt is please?
Camerart

 

[Bystander]

I'm not talking about raising the boiling point!
Any ideas as to what this salt is please?

Sodium or magnesium sulfate or chloride, however you will be raising the boiling point.

 

[camerart]

Hi B,
Ah, thanks.
Can you explain a little more what happens please, and how much difference it makes?
Als how much works best?
Thanks, Camerart

 

[Bystander]

https://www.google.com/search?q=boi...j0i433i512.17088j1j7&sourceid=chrome&ie=UTF-8

 

[camerart]

https://www.google.com/search?q=boi...j0i433i512.17088j1j7&sourceid=chrome&ie=UTF-8

Hi B,
Thanks for the link, but through the complication, I could only see boiling point elevation.
I'm not asking about raising the boiling point, but I want to know if it's possible to store more heat energy, in water well under boiling point.
C

 

[Tom.G]

Here is a graph of the specific heat of NaCl in H₂O. It looks like the specific heat decreases as salt is added to water.

https://www.engineeringtoolbox.com/docs/documents/1187/sodium-chloride-water-specific-heat.png

Above found with:
https://www.google.com/search?&q=specific+heat+sodium+chloride

Cheers,
Tom

 

[camerart]

Here is a graph of the specific heat of NaCl in H₂O. It looks like the specific heat decreases as salt is added to water.

https://www.engineeringtoolbox.com/docs/documents/1187/sodium-chloride-water-specific-heat.png

Above found with:
https://www.google.com/search?&q=specific+heat+sodium+chloride

Cheers,
Tom

Hi Tom,
Thanks for the links. (While I appreciate the links to Google, it doesn't make things simpler) I've searched myself and find this very difficult route to understanding. I'm not lazy!

Can I point out that I'm slightly Dyslexic, so what may be obvious to some may not be obvious to me. I keep searching and find similar questions, where they may be answered by comparing a block of Iron compared to a 'block' of water, this complicates things.

If a litre of water, 'A' has salt in it, from the graph link, I see it will have a lower specific heat, than litre of water 'B'

For thermal storage, is it better to raise or lower the specific heat of a volume of water?
In other words, is it an advantage to add salt to store more heat in a known volume of water?

C

 

[russ_watters]

For thermal storage, is it better to raise or lower the specific heat of a volume of water?
In other words, is it an advantage to add salt to store more heat in a known volume of water?

Well, you asked the initial question and it comes with an implied answer: it is often better to have a higher specific heat because that means you need less of the storage medium. So, additives are often there because of boiling or freezing point concerns.

So I think then the answer to the original question is no, it's not really the way it works that you add something to water to make it store more heat, you just use more water.

 

[camerart]

Hi R,
Thank you for a clear answer.
I wonder what it was that was done to those greenhouse bottles of water? Maybe the idea was simply incorrect.
Cheers, C.

 

[hmmm27]

Usually, stuff is added to water to lower the freezing point, to prevent water lines from getting clogged, and bursting from ice expansion. And also, usually, it lowers the heat-capacity.

For a greenhouse, it'd be neat if you could raise the freezing point of a ballast.

 

[OmCheeto]

Perhaps you read this article:

Chill: out! Storing heat inside a greenhouse using salt
...
The salt formulation used inside Carmenia's greenhouse is capable of storing 62 times the amount of heat by weight as water.
...

I'm late for a very important date, so I don't have time to figure out if this is nonsense or not. See you next week!

 

[camerart]

Hi O,
I think it may be true, but not what I'm asking. The salt is a solid, like sand or concrete, and can store more heat than water, but for my experiment, I specifically need to use water, for convenience, and scale.

I could have tried a ton of concrete, then found that a ton of this salt would be better, then I would have to get rid of the concrete, so water it is :)

I'll start another thread about my idea, and see what you think. Note: I prefer simple words of what you think, rather than Google links or deep science.
C.

 

[hmmm27]

I don't think you need another thread ; rather to define what you're trying to accomplish with your experiment.

You might be thinking of molten-salt thermal storage, which is a phase change for higher temperatures than boiling water.

Or, you might not.

 

[camerart]

Hi H,
I usually start a fresh posting, if it is a different subject, even if it is related.

https://www.physicsforums.com/threa...-solar-panel-comparison-using-a-lens.1016680/
Cheers, C