Who has experience in "HEATING WITH ICE" ?

[bumcrack]

Sorry, forgot to say, cold doesn't travel. It just absorbs heat. Like us, molecules always want more, they rarely give energy away...

 

[JohnBoyZ]

How about using any excess power during the summer to run an electrolysis plant to generate hydrogen and then compress this into liquid form for storage in large pressure vessels. then in winter the stored hydrogen can be used to run fuel cells to generate electricity for heating and powering the house. Simples!!! I cant see any reason this shouldn't be widely adopted LOL

 

[Earthstore]

I find all of this very interesting, in simple terms we are tring to change one form of energy into another so we can use it when we need it, right?
The problem is
A; loses, every time we change the form of or try to store energy, it incures losses.

B; The cost of building or running a system outways the benifits.


My belief is that soon, somebody will come up with a great idea, things are moving fast, when I was a boy, if you had told me that we could heat our homes with just air going through a fridge that works backwards, or you could have these glass things on the roof that produce electricity, I would have said you were barking, but here we are!
My original interest in this industry was water, watching a waterwheel actually, it is one thing in this country that we have plenty of, and it's constant, 24 hrs a day 365 days of the year,springs, streams, brooks, rivers, a reliable energy source that just flows away.. hmmm

 

[germ]

Right,
In order to store energy for use at a later point we need to store it, which rightly comes with the problem of storage and the attempt the preserve as much as we can.
That's why I find the idea of turning it upside down and restore spent energy when there is plenty about so attractive.
It means you don't have to think about storing the energy!

germ

 

[bumcrack]

How about using any excess power during the summer to run an electrolysis plant to generate hydrogen and then compress this into liquid form for storage in large pressure vessels. then in winter the stored hydrogen can be used to run fuel cells to generate electricity for heating and powering the house. Simples!!! I cant see any reason this shouldn't be widely adopted LOL

You are totally over complicating things. It would be much simpler to divert the excess PV energy to a high power laser, and then use this laser to cut MI5 agents in half, and knock satellites off their orbits axis, possibly from a small tropical island. Your installation will need approval to local standards by a Mexican plane spotting dwarf.

When you have done this, and taken over the world, you can increase the export value for PV to something like 12.5p, thus negating the need for inefficient and complicated power storage systems.

Job done.

 

[germ]

now we are talking!
when do you want to start?

 

[JohnBoyZ]

You are totally over complicating things. It would be much simpler to divert the excess PV energy to a high power laser, and then use this laser to cut MI5 agents in half, and knock satellites off their orbits axis, possibly from a small tropical island. Your installation will need approval to local standards by a Mexican plane spotting dwarf.

When you have done this, and taken over the world, you can increase the export value for PV to something like 12.5p, thus negating the need for inefficient and complicated power storage systems.

Job done.

Yes I Agree Mr Blofeld

 

[sharpener]

It depends what you want to do with them. A bit of clever battery charging kit could follow a transducer to ensure zero export in the day.

What you then need is an inverter that can cope with paralell operation, and drop out when the batteries are exhausted...

You are not alone in thinking this bumcrack, both SMA and Steca make systems to do precisely this. They also enable your PV system to operate legally as an island generator so you can be completely independent of the grid if necessary.

STECA Steca Solsafe: no more power outages!

Backup Systems. SMA Solar Technology AG


Unfortunately SMA have told me there are no plans to market the Sunny Backup S in the UK (which is the one best suited to domestic installations) as it will not cope with TT supplies (what proportion of the UK market is that?)

Have not asked Steca yet, maybe a Senior/Steca distributor can tell us.

 

[bumcrack]

I believe a company called outback make hybrid inverters, for the Australian market, so unlikely g83 compliant.

You could probably acchieve a reasonable system with some changeover contactors on the pv dc and battery charging.

The normal switching operation allows the batteries to be in parallel for 12v charging, a secondary operation series links the batteries to give 240 v dc ( 10 x batteries ) and a third switching operation changes the dc inverter input prom pv modules to 240v dc battery....

 

[edexlab]

Some outback products are available here but I think its only their island/Dc circuit equipment
I have done an Island system (Sma) with a 4000Tl in our premises, install was fairly straightforward , however getting it set up there are a lot of parameter settings you can change / adjust and it is difficult to determine the loading it will cope with ,when we installed it I could'nt access the design program and to be honest I have'nt had time to get it running to full capacity yet and need to add more circuits/loads to get the most out of it , and also get the webbox done too this should be sorted in the next month as I'm going to have a bit more time i suspect

 

[germ]

All fine, the battery version may be the answer for short term supply.
But I'm trying to find a way to level out the yearly cycle of pv generation.
To much to use in the summer, to little in the winter!
None of that is an answer to this problem!
It may be a good answer to bridge a cloudy day, but not to heat your house or so.
Regards
germ

 

[bumcrack]

But I'm trying to find a way to level out the yearly cycle of pv generation.
To much to use in the summer, to little in the winter!

What you are trying to do here is nigh on impossible due to cost. Long term thermal storage, be it hot or cold will require vast amounts of insulation in our UK climate. If you lived on a pole, or at the equator the whole thing would be needless anyway, as you have masses of extreme temperature to play with, just with ambient.

Long term electrical storage is more practical, but the cost of high effeciency batteries will price it out of being worthwhile. Li-Ion batteries will hold charge for 20 times that of lead acid, but at what cost?

Your best bet is to make the best of what you have in summer. The key to this is to finely tune your setup so it never exports. I do this at work on G59 stuff where the site does not have an export agreement with 100kw CHP, its not difficult. The way we work our kit, is to modulate the output of the generator such as there is always at least 20Kw of import....if you have import you cannot be exporting at the same time.

A current transducer set to read export direction of current, and a basic PLC is all thats needed. You would setup the PLC to switch loads on based on export at the time, and cascade them on as PV production increased... You could do this with a 4-20mA loop through several trip amps with different thresholds and enable signals, but its a bit messy.

So for winter, on a grim day, what is your 4Kw PV producing at miday? 300w? It's not even worth bothering with, your frigde/freezer security alarm will absorb this. On a bright cold day though, when you PV is singing between 10am and 2pm, you might want to chuck power into a set of batteries and heat some water.

In summer, its all go, when export is greater than 1Kw, charge batteries, if it stays up there with the battery charger on, you heat some water, if it still stays up there you increase the charge to the batteries, and heat more water...

All you can really do, without spending thousands of pounds is store energy for use on a daily basis, after the sun has gone down.

The only other thing you could do for long term storage, but it would be hugely inefficient from FIT based PV, is to generate HHO, but it's about as safe as weapons grade plutonium.

 

[germ]

Hi Bumcrack,
thank you very much for your informative and interesting input, much appreciated!
But, could you please do me a favour:
Could you please read the thread fully from the beginning and you will understand that I exactly do not want to store energy due to the mentioned reasons like costs and losses!!!!

The principle of the so called ice-heating is that you got a large underground storage of water from which you extract it's energy in the winter via a heat exchanger until it freezes and beyond!
So you don't store any energy as such, the water in the storage is standard tap water temperature. That's the beauty of it: no insulation needed! Contrarary you want the surrounding ground to inject some of the ground temperature into the beeing cooled water. If you would want to heat the water in order to store the heat for the winter you would need arround 10 old milk tankers and several feet of insulation. And you would find that you'd still run out of hot water a couple of months down the line because water does not store energy very efficiently! You'd need to use oil as it is used in transformers for example.
Then in spring and summer when it gets warmer the excess pv energy can be used to help melting the ice throughout the summer!
You see, I'm not talking about storing energy at all. Only negative (spent) energy, that's the beauty - no cost in upkeep and relative low outlay!
Best regards
germ

 

[sambotc]

Interesting idea, although i cant imagine it would take long to freeze the water? What are the advantages of using water rather than plain old ground source & P.V to reduce the running costs?

 

[germ]

I believe earth is a very good insulator and you only loose something like 1deg Celsius per meter. And apparently due to it's unique construction of H2O you can still extract more energy once it's frozen solid!
So it sounds to me as you get more energy out of water than you get out of the ground!

germ