Thermodynamic Solar Panels

[Gavin A]

same as really.

I suspect they'll only be viable for that in well insulated houses probably with some form of biomass boiler, or at least a stove for the main room to act as back up / supplementary heating in extreme conditions (when the efficiency of the system will be at it's lowest).

I suspect that wall mounting may be preferable for these purposes to reduce the potential for snow build up around the panel, and vertical mounting also has the advantage of maximising winter solar gain while reducing the peak summer solar input by around 40% to avoid overheating in summer.

 

[Eco Deal]

Seems a good product ! need more data !

 

[Jaycee]

Gents

Google thermogroup uk, they have a lot of technical info there that answers all the questions you are raising.

Basically it is not a solar panel, it works on atmospheric conditions, It works like a fridge, but only in reverse, producing heat instead of cooling.

 

[solarfred]

We still need real time data from real installations. All I get is "brilliant - I have hot water 24/7 no problem..." which is not real data. A heat pump will get you 55c but you need 65c for legionella and that can only be done by immersion element?
Several posts on Irish forum have been started and when I ask for data they suddenly disappear.
Latest guy had a monitor on the compressor power cord to measure usage. He had a bath and showers and washing machine and dishwasher etc. I asked if the washing machine and dishwasher were cold fill. And if there was an immersion option which was monitored.............silence!
I give up.

Oh and here is the response I got from questions direct to the Thermogroup UK some weeks ago after I went through the website information:
(Their response in italics)

We could do with going through this over the phone at some point but i have answered in brief below

1. Why does it state on one page will supply "100% of your hot water" and on another page "up to 100% of your hot water"
2. Because for domestic systems it is 100% and for commercial it is often a pre-heat.

2. When it compares the cost for a large installation it states there is electric heating. But the system does not need any back up heating?
The existing supply was electric only and the new installation only needs the compressor and an immersion for the anti legionnaire cycle.

3. It provides a running cost but only calculates the running cost of the 9kw heater, it does not include the running cost of the heat pump??
4. ??

5. For the domestic install it says the pump uses 390w so I assume the commercial system would be multiples of that number?
Exactly

5. Why in a domestic situation does it refer to kWp which is a measure of solar PV output not an electric heater. If it is a standard immersion at 3kw then the cost will be £1.26 per day.
This is a typo on an early presentation,sorry.

6. Based on corrected numbers the payback on their calculation is 10 years. But I do not believe any of their numbers.
7. There maybe some confusion here.

7. If you use that calculation on the commercial install - let's say the 1000 litre cylinder has 3 x 3kw immersions at 18 hours = a payback time of 10 years. The running cost is £12.47 a day.
The commercial installation uses the 1000 litres 4 times a day.

Or am I missing something bleeding obvious??
No just a little confusion.

So yes I am confused.

 

[Jaycee]

I agree there are some teething issues with thermodynamic panels!

All of the questions you have asked are valid points that need to be addressed before we are convinced by the sales literature.

Drop me a message with your email address, and I will try my best to get your questions answered, or at least find somebody who can answer them for you.

 

[jetski]

Hi gents I came here looking for any threads on this subject as I had a salesman showing me this product today, I'm quite supprised that it still very much in it's infantsy here with not much info on it as the salesman seemed to be having quite a lot of take up on it so far, any way the system was a 2000 ltr cylinder with an install price of £6969 which you get £300 back more or less straight away he was also showing me the tarrif scheme like the solar energy one which would pay a set sum each year for 20 years index linked once again which would make it worth while but I've yet to find any evidence on the net that that is true infact what I saw on here from another link was something about a 7 year tarrif if that's right he's got it totally wrong.

 

[solarsavings]

2000ltrs, is that a commercial system? How many panels did he say you would have installed with that size cylinder.

 

[jetski]

No that's just a domestic hot water system and apparantly you only need the one panel for it to work.

 

[solarsavings]

Then i think you have been quote for a 200 ltr cylinder and not a 2000 as per your post above. £6969 you say. I not sure that's a good buy sounds more like good bye to me.

 

[jetski]

Yes your right sorry my mistake it would be a 200 ltr.

 

[solarfred]

OK just do this simple math. If a normal immersion heater uses 3kw and it is on one hour in the morning and one hour in the evening that = 6 kWh per day. That costs about £0.15p x 6 = £0.90p per day.
Over one year that = £328. So to pay back the capital outlay of your Thermodynamic unit based on alternative nil capital cost alternative = 18 years. Chances are your thermodynamic will need new expensive parts within 18 years whereas an immersion is £30 a time.
The immersion is subject to the increases in electricity prices but then so is the Thermodynamic unit as it runs a heat pump for hours on end. (we are not sure what happens in a decent cold winter because no one will offer any data). I understand to heat 250 litres from cold takes 8 hours at 550 watts.

If you go for solar thermal after the initial capital outlay of £2-3,000 there is no other cost and it will supplement the immersion up to 100% in summer and 50-60% in winter. Running costs are negligible.
Replacement parts are minimal cost. If you use existing gas or oil backup you are usually just topping up the water temperature so probably cheaper than the immersion option.

So if the Thermodynamic actually cost £3,000 then it would need to compete on running costs with thermal based on similar capital cost. I don't think it can. If you run an immersion backed up thermal system I would think it will be cheaper than a thermodynamic system over the short and long term.

 

[Jaycee]

A thermodynamic system only has 1 part that could possibly ever need replacing, and that's the compressor, which is just like the one on the back of your fridge freezer.

When have you ever had to replace that?

 

[solarfred]

I think you are overlooking the actual device that transfers the heat into the water.The compressor just compresses gas into liquid which then goes through a "thermal block" which is the guts of this device. I can't find the test document I found a while back but it was certified and tested by Intertek in the far east (where I assume it is made). The "thermal block" is the magic device or heat exchanger which makes it all work and costs the money. If I find the information I will post it. Doesn't change the maths though.

 

[solarsavings]

Jaycee how closely have you looked at the thermodynamic packages that are on sale in the UK.

 

[jetski]

Thanks for the comments guy's keep them coming, and to Solarsavings I'm sorry I cant reply to your pm as I've not had the minimum 15 post's on here.