Came across this link

http://www.greenserveuk.com/thermodynamics/

Do they work as advrtised? Are they better than evacuated tubes or flat plate collectors? What's the catch?

Extract from the website:

Thermodynamic Solar Energy Advantages
[SNIP]
Non-combustible refrigerant

Are there many (any?) commonly used combustible refrigerants?

it could be water! or freon more likely !

From the website: "Thermodynamic solar systems employ two types of known ecological fluids that observe the European Standards: R 134-A and R 407-C. Notice they do not contain ammonia and are considered ecological."

From wikipedia about R 134-A - http://en.wikipedia.org/wiki/1,1,1,2-Tetrafluoroethane - "Recently, 1,1,1,2-tetrafluoroethane has been subject to use restrictions due to its contribution to climate change. In the EU, it will be banned as of 2011 in all new cars."

"R-407C is a zeotropic hydrofluorocarbon blend of R-32, R-125, and R-134a".

Hardly what I would call "ecological"! Though they are very useful and widely used.

Posted By: tonyI would call these harmful, they are the kind of things that mess up the ozone layer.

No - these are refrigerants that were introduced specifically to avoid damage to the ozone layer! But they do have global warming potential.

http://www.engineeringtoolbox.com/Refrigerants-Environment-Properties-d_1220.html

I like the idea, but don't think of them as solar panels, think of them as heat pumps.

The problem is I suspect in practise there are probably better solutions, e.g. air source or ground source heat pumps.

actually the more I think about it , evacuated tubes and an ASHP would be a better solution, and more efficient.

Posted By: YouGen-CathyIf it's so brilliant, why haven't I heard of it?

I think you're probably best placed to answer that question.

Posted By: YouGen-CathyAm I right in thinking that if it sounds too good to be true, then it probably is?

no, it should work as advertised. The problem I'm finding with it is that it's too expensive to justify for more people, and I understand is based on patented technology so isn't really subject to competition to drive prices down.

It's annoying as there's nothing complex about it, and nothing new either as it's just a reverse engineered fridge, but with the heat exchanger mounted externally instead of on the back of the fridge, and extracting heat from the air instead of expelling heat into the air.

I've been collating and evaluating these since I saw them at the London Eco House Builing expo
- http://www.silverspray.co.uk/2012/03/27/ecobuild-thermodynamic-panels-heat-exchanger/

They've recently been installed at Maidstone UTD Football Club
- http://www.silverspray.co.uk/2012/08/16/thermodynamic-installed-at-maidstone-utd-football-club/

To me, they are a heat exchange system using a panel, which is ideal compared to an air source heat pump or ground source air pump. Neither of those will work well on my site, which is right by the sea.
- sea air has a poor record with the survival of air source heat pumps.
- it'd be lots of money to put ground source shafts down into the cliff I'll be on.

You can put the panels inside, outside, any angle ..... They can cause shading on each other without the same negative that gives PV panels.

If I want to boost the system because the house isn't as thermally efficient as the calc's suggest, I'll be able to "just" add another panel to the rest of the system.

I'd obvioulsy like them to be cheaper, but they are a currently favourite and likely item.

I've been aware of "Thermodynamic solar panels" for some time and am interested in the system as it ticks a lot of boxes for me.

As far as I can find there are two manufacturers of these systems, the best known being Energie in Portugal http://www.energie.pt/ but also a company called Energy Panel in Spain. http://www.energypanel.es/productos.aspx?idFamilia=1&idProducto=1

The problem I have with them is a seeming lack of independent verification of their claims for running costs. I've seen mention of various installations being independently monitored but all my previous efforts to get these reports have so far failed.

Does anyone know of any such independent verification?

"GaryB"
- nice summary, that fits my undestanding.
- I like the idea of 24 hour, year round hot water potential year, and my site means ASHP or GSHP won't work.
- my understanding is that compared to straight solar thermal Thermodynamic panels will use more electricity, but require less of an alternative / back up system fro winter months.
- From www.decc.gov.uk/en/content/cms/meeting_energy/microgen/solar_thermal/solar_thermal.aspx,
"Solar thermal should work all year round during the day but consumers will probably need to heat the water further in winter months, using a boiler or immersion heater."

So any independent verification of their claims for running costs, that "Chris P Bacon" or anybody else can get, would be superb.

I'm also looking to explore some hot water heat recovery via a heat store and the Thermodynamic panels !
- http://www.silverspray.co.uk/2012/09/06/thermodynamic-panels-a-heat-store-or-heat-recovery-system/

I'm not planning a pool, but maybe a hot tub, and even without a hot tub, being able to re-capture heat from showers, the bath etc. seems a good idea to plan in.

Those look like the same panels.
Interesting from the video that they have a customer where the panels were still "generating" hot water when the panels were covered in snow.

Posted By: SteamyTeathe COP will be rubbish though

Not necessarily, because as well as being admirably translucent, snow is a great insulator, much like Aerogel, and will kill the usual concurrent re-radiation loss to even colder sky and scenery, which conventional wisdom says makes deep-winter solar collection unviable.

Can you re-state that Ed - I don't follow.

I very much doubt that snow is sufficiently “admirably transparent” to be useful. E.g., my amorphous PV panels don't generate much when covered by even 10 mm or so of snow. Snow's high albedo is a rather famous cause of reduced solar energy absorption, after all.

It's noticeable on those panels, for example, that snow can stay for a while. However, if it's partly cleared (e.g., use of gloved hand to remove the lose snow leaving patches stuck on more tightly) then sunlight falling on the clear parts can warm the surface and thereby clear the rest quite quickly.

These “dynamic” panels may well work well when covered with snow if the snow is temporarily warmer than the working fluid. However, the working fluid will cool the panel and the immediately adjacent snow pretty quickly. I think the insulating and reflecting effect of the snow will mean that the heat removed will not be replaced leading to the system becoming progressively less effective.

I'm talking about a relatively thick layer of snow. A mm or so layer of snow or a coating of frost doesn't seem to affect ETs much, from what I hear, and so probably wouldn't be so harmful to a system of this type either.