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    • CommentAuthortullyfoyle
    • CommentTimeAug 25th 2011
     
    Has anyone tried Thermodynamic Solar Panels. claimed to work 24/365. One panel is said to supply enough DHW
    at 55 centigrade for 6 people every day - guaranteed.
    Ted
    • CommentAuthormike7
    • CommentTimeAug 26th 2011
     
    Looks like it's a heat pump with a solar-assisted air to liquid heat exchanger on the outdoors end.
    • CommentAuthorGavin_A
    • CommentTimeAug 27th 2011
     
    yep, that's what it is mike.

    depending on the heat pump, it'll be better (better COP) than an ashp in sunlight, but probably worse at night unless there's much wind to move air across it, although it will have a bigger surface area than in most ASHP's which will compensate for this to some extent.

    could be a good option for some though.
    •  
      CommentAuthorJSHarris
    • CommentTimeAug 27th 2011
     
    This sounds like a good idea. Coupled with a well-insulated, fairly high thermal mass building it should be possible to gain enough heat during daylight hours to sustain demand through the evening/night, as well as provide DHW.

    It also has the advantage of not needing (potentially noisy) fans, which is one thing that has put me off using an ASHP.

    The only potential problem I can see is the possible need for periodic recharging with refrigerant, although this is probably no worse than that needed for something like an air conditioning system.
    •  
      CommentAuthorSteamyTea
    • CommentTimeAug 27th 2011
     
    is there not a potential problem with condensate and frosting. Not sure about ASHP but GSHP tend to use coolant at just below 0C. Do this with a panel and it will frost over at night.
    • CommentAuthorFred56
    • CommentTimeAug 28th 2011
     
    How does this technology stand with MCS and SAP?
    • CommentAuthorSteveZ
    • CommentTimeAug 28th 2011
     
    Just looked at the Thermasol website and video. If these claims actually hold up, it looks to be a great idea, efficient and fairly simple to run.
    You might be interested in another idea I checked out a while ago. I found a couple of manufacturers of PV-T panels (Voltherm and an Italian company) where the photovoltaic panel is backed by a liquid-based cooling system, rather than the gas in the thermodynamic panel. There is a British company using these panels and their own heat pump to provide hot water (Newform Energy), although it may be still in development. You get a greater electrical output from the panel, as it operates at a lower temperature due to the cooling. You gain a large area of solar radiation collection on your roof, which, according to the literature and published results, will collect usable amounts of heat energy even at night with sub-zero temperatures. I thought at the time that the initial cost would probably be too high for me and wondered if there would be enough energy available from the roof panels to be useful (and the added complexity is to be considered too). If one gas-cooled panel can provide enough energy as claimed above, several liquid-cooled panels should not have a problem. In theory, you should get the FIT payments for the PV side and RHI for the Solar Heating and more for the Heat Pump function, although not yet definite.

    http://www.newformenergy.com/hybrid-solar-solution
    • CommentAuthorGavin_A
    • CommentTimeAug 28th 2011
     
    we're about to start installing new form energy's PVT / Heat pump systems. Somewhere on here there's a thread about PVT panels from a year or so ago where I said I didn't see the point unless they had a heat pump attached, now someone's done it, so we'll now be able to offer 4kWp solar systems which generate approx 15-20% more electricity per year, plus hot water all year round, and maybe something like 50-60% of the household heating.

    I reckon these systems will work very well for use with either a small ground loop for the heat pump, plus a big buffer tank, and biomass boiler for the peak heat demands in the depths of winter, with the heat pump supplying most of the heat the rest of the time.
    •  
      CommentAuthorJSHarris
    • CommentTimeAug 28th 2011
     
    I'll be very interested in seeing how this works out, although using a biomass boiler seems odd, in light of the non-sustainable nature of burning biomass for heat.

    What I will be very interested to see are the real-world performance figures, rather than the manufacturers claims.
    • CommentAuthorGavin_A
    • CommentTimeAug 28th 2011
     
    Posted By: JSHarrisI'll be very interested in seeing how this works out, although using a biomass boiler seems odd, in light of the non-sustainable nature of burning biomass for heat.

    yeah, but that's only perceived wisdom according to this forum, rather than reality, so I'll not worry overly about that other than specifying high efficiency, low polluting gasifying log boilers.

    anyway, let's keep at least one thread on topic eh.
    •  
      CommentAuthorJSHarris
    • CommentTimeAug 28th 2011
     
    I don't want to go off topic, but there is absolutely no question about biomass being unsustainable, nothing to do with "perceived wisdom" here or anywhere else, it's just basic logic. A simple calculation giving the area of land needed to heat a home by burning biomass shows that we simply don't have the land available. How many acres of woodland are needed to heat a single house, assuming that the wood is sustainably managed? Is it realistic for every home to own and manage such an area of woodland? No, is the simple answer.
    • CommentAuthorGavin_A
    • CommentTimeAug 28th 2011
     
    Posted By: JSHarrisHow many acres of woodland are needed to heat a single house, assuming that the wood is sustainably managed? Is it realistic for every home to own and manage such an area of woodland? No, is the simple answer.

    you're making the same basic mistake that lots of people here seems to make.

    nobody I'm aware of has ever seriously suggested trying to heat every home via biomass, and making that point on a thread where we're discussing solar/air sourced heat pumps as a source of heating is particularly odd.

    UK heating is currently supplied by gas, oil, electricity direct and via heat pumps, and to a small extent coal and biomass. In future biomass will hopefully move up that list a bit, probably mostly replacing oil, and electric, and probably matched in varying degrees with solar water heating, and heat pumps, with the biomass providing top up heating.

    Biomass is (or at least can be) a sustainable fuel source when used as a part of the overall mix of available lower carbon fuel sources, in situations where it is sensible to use it - ie mostly in the countryside in areas where local fuel supplies are available, and for the time being at least, where mains gas isn't.
    •  
      CommentAuthorJSHarris
    • CommentTimeAug 28th 2011
     
    Basically, you're arguing that a few selfish individuals can use many times more land for their own energy needs than the vast majority of the population, which isn't sustainable in my view.

    Biomass is viable only as a very small scale energy source where it is a waste product. The whole idea of wasting agricultural land by growing fuel for a tiny percentage of the population just doesn't make sense, no matter how anyone chooses to do the sums or try to justify their own view.
    • CommentAuthorowlman
    • CommentTimeAug 29th 2011
     
    I dont know about anyone else but I'm interested in the new thermodynamic panels and how they work in practice, not another rant against biomass, which incidentally confuses domestic and commercial biomass. Please can the thread stay on topic. Start another thread if that is what you want to discuss. :sad:
    •  
      CommentAuthorSteamyTea
    • CommentTimeAug 29th 2011
     
    Yes some decent data on them in our climate would be interesting.
    What I would like to see is an Instantaneous Power/Time chart and some data on when and power the HP is producing. Couple this with the energy demand of the HP would be interesting.
    Have I mentioned burning on this thread yet :wink:
    • CommentAuthorowlman
    • CommentTimeAug 29th 2011
     
    Presumably installers would have to be MCS accredited in all three disciplines,- more upfront fees for the workers? I've only just nicely got the PV installed and about to start the ST and along comes this, and the goalposts start to move again, "C'est la vie".
    •  
      CommentAuthorSteamyTea
    • CommentTimeAug 29th 2011 edited
     
    Yes, the FIT/RHI/MCS system really skews the marketplace. I think the next review may have to address this a bit.
    My gut feeling is that separating the systems will not be so bad even if it does take up more roof area, bit like driving around in an old VW Camper just for the occasional night away, a hotel and a small car would work out better (but then I hanker for an old split screen and want to depress prices, but then I saw a McGregor 26 and now want one of them instead)
    http://www.macgregor26.com).
  1.  
    Guys, we are currently getting pricing for 4KW PV system and Solar System and one of the installers suggested these combined PVT pannels as the better approach. He didn't mention anything about heat pumps though, we have gas boiler and are going to have a thermal store and I assumed the water heated from the PVT panels would simply heat the ST in same way as tradditional solar but is the issue that the return temp from the panels is much lower? Would we have to have a HP or they just suggesting its an option for complete heating solution?

    The statement "The chart above shows PowerVolt panels absorbing energy at -10°C in the dark, meaning that the system will perform at higher efficiencies than air-source heat pumps in similar sub-freezing overnight conditions.". Can someone explain this? Why will the panels provide anymore heat in the dark @ -10°C than an air source HP?

    I don't like the idea of installing such a new technology, although I guess its just a combination of very established and proven technologies!
    •  
      CommentAuthorJSHarris
    • CommentTimeAug 29th 2011
     
    I'll admit that it's the claimed low temperature performance that has me puzzled a bit, for the reason mentioned elsewhere in this thread. ASHPs generally have to have some means of preventing the evaporator heat exchanger getting iced up. They can resort to using either some form of supplementary air heater on the evaporator side whenever the outside temperature drops too low, or they can periodically reverse the cycle to defrost the evaporator heat exchanger, but both methods waste energy.

    I'd have thought the same would happen to these panels whenever the outside temperature drops to a point where the panel surface ends up below freezing point. It's possible that they reverse the cycle to periodically defrost the panels, but this is even more wasteful on an open panel than it is with a fan-blown exchanger, as at least with the fan-blown unit the fan can be turned off during the defrost cycle to minimise heat loss and speed up defrosting. If they do use a periodic cycle reverse for defrost it will dramatically reduce COP I'd have thought. Given that we frequently seem to have winters where it's both cold and damp I suspect that panel icing must be a potential problem in our climate.

    Having said that, if this system were used primarily during the day, to charge up a big thermal store, then it might not be necessary to run it at night when there would be a greater risk of icing up.

    I'll be interested to see how they get around this potential problem, as it's the only downside that I can see in what looks to be a clever idea (other than maybe a high cost.....).
    • CommentAuthorGavin_A
    • CommentTimeAug 29th 2011
     
    Phil - without the heat pump the PVT panels will need to operate for a large part of the time at 50-70 deg panel temps in order to get the water in the tank up to 60/65degrees. This means any improvements in PV performance will be negligible / only apply for small parts of the day.

    Combining it with a heat pump will mean 55/60 deg water temps can be gained from 25 deg panels temps (or lower), meaning the PV panels can operate at or around their actual rated output in full sunlight rather than losing 15-20% of their output (due to ~0.45% per degree loss in performance of crystalline PV panels)

    steamy tea - separating the systems out would mean the PV system didn't benefit from the cooling effect, so I'm not sure where you're coming from with that idea.

    These systems will not be suitable for all situations, as apart from anything else, the amount of heat that can be delivered from them in summer is way in excess of a standard households hot water demand (depending on the size of the system of course). that said, if you use the uninsulated version it ought not to make much difference to the PV panel temp when not running, so it would still be beneficial for the time it's operating, just not as much so overall compared to situations with high levels of year round heat demand.

    JSHarris - I agree that the benefits in minus outside air temps will be largely down to the no/minimal defrost cycle. In an ASHP the defrost cycle is needed more to prevent the air intake/exhaust actually freezing up, and the fan and other moving parts getting iced up. None of this applies the a PVT so long as it's above the glycol's freeze protection levels it'll be fine (though icing up of the heat fins will impact on the performance of the system).

    The system's also not really being sold as something that's supposed to be capable of doing the houses entire heat load, more something that can do the bulk of it for much of the year, but will need a secondary heat source during the coldest periods. Hence matching with biomass, and / or a small ground loop for the heat pump (potentially with summer heat being pumped into it if ground conditions allow), or the existing oil / gas heating system.
    • CommentAuthorGavin_A
    • CommentTimeAug 29th 2011
     
    Posted By: owlmanPresumably installers would have to be MCS accredited in all three disciplines,- more upfront fees for the workers? I've only just nicely got the PV installed and about to start the ST and along comes this, and the goalposts start to move again, "C'est la vie".

    yes, but then why would you want this not to be the case?

    I'd not want a heatpump bod installing these without knowing anything about PV or solar thermal, similarly as a PV and solar thermal bod I'd not want to be installing the heatpump and heating side of things without being properly trained in it (although I'm sure I could sus it out).

    These are ~£30k systems, so it's reasonable for a customer to expect the installer to be fully trained in all relevant disciplines.
    •  
      CommentAuthorJSHarris
    • CommentTimeAug 29th 2011
     
    Whilst I can understand that this system doesn't have fans etc to ice up, any ice on the heat exchanger will dramatically reduce it's performance, as ice is a pretty good insulator. This will present a problem at outside air temperature significantly greater than zero, as the heat exchanger will always be operating a few degrees cooler. A damp day with an outside air temperature of maybe 4 or 5 deg C would be enough to get the heat exchanger seriously iced up from condensation or frozen rain I'd have thought, yet they seem to be claiming that it still works OK down to -10 deg C, which I find a bit of a puzzle.

    I still think it's a potentially good solution though, particularly if combined with good thermal storage. Pity about the price tag though, £30k is a heck of a lot of dosh and will put it out of reach for many, even with the current level of FITs subsidies.
    • CommentAuthorGavin_A
    • CommentTimeAug 29th 2011
     
    yeah, I'm not entirely sure on the price, just got a ball park for a 4kWp system, inc heat pump, buffer tank, hot water tank, controllers etc. I'd hope to bring that cost down a fair wack, but the installation isn't going to be that quick, or simple in most cases.

    It should be eligible for both FIT and RHI, and basically most of the heat generated during daylight hours will effectively be largely free of fuel costs.

    I'm not entirely sure about the low temperature performance claims, it could also be they're also mainly referring to daytime situations when the outside air temp is below freezing, but the panels will be absorbing heat from the sun. I guess the other factor is the huge collector surface area - effectively around 50m2 if you include both sides of the panels.
    •  
      CommentAuthorJSHarris
    • CommentTimeAug 29th 2011
     
    I think you've heat the nail on the head mentioning the large evaporator heat exchanger area. That would allow the system to run with a much lower delta T than would be typical for a conventional ASHP, so reducing (but not eliminating) the icing problem.
    •  
      CommentAuthorSteamyTea
    • CommentTimeAug 29th 2011
     
    Posted By: Gavin_Asteamy tea - separating the systems out would mean the PV system didn't benefit from the cooling effect, so I'm not sure where you're coming from with that idea


    Think JSH is really asking the same questions. But if the HP is not running much in the summer, then where is the advantage of cooling the panel in winter.
    Don't get me wrong, I like the idea, just think it is a bit complex for little or no gain, and at that sort of money you could buy a lot of insulation.
    I would have to see real operational data as well as manufacturers data before I could recommend that. Is there any real data yet?
    • CommentAuthortiimjp1
    • CommentTimeAug 29th 2011
     
    It's such a shame that DIY projects cannot be taking advantage of FIT's have you all noticed how prices have skyrocketed through MSC accreditation requirements which is not good for those clever DIY people who want to save money and do things as cheap as possible.

    Maybe i'm wrong but all these stitch up regs are great for those who want to make money but not those who want to save it. I know there is a market for specialists but you don't have to use most of them if you don't want to throughout your build but some things you have no option and its mostly there to stop DIY people having fun.

    Obviously the final connection to the Grid has to be correct but as long as the circuits are protected correctly against faults which after all can occur in specialist equipment, whats the difference.

    What would happen if you got an MSC company to install 1Kw of solar PV and then you as a DIY man added your own home made panels to the curcuit to increase the output?

    just a simple query lol
    • CommentAuthorGavin_A
    • CommentTimeAug 29th 2011
     
    Posted By: tiimjp1It's such a shame that DIY projects cannot be taking advantage of FIT's have you all noticed how prices have skyrocketed through MSC accreditation requirements which is not good for those clever DIY people who want to save money and do things as cheap as possible.

    erm actually, not really.

    installed prices for 4kWp of pv have dropped from around £16-18k under clearskies to £10-12k now, 18 months later.

    And the panel prices have also dropped accordingly, so anyone wanting to do it DIY has also benefitted, although they'd not be eligible for FIT's unless signed off by an MCS company.
    •  
      CommentAuthorSteamyTea
    • CommentTimeAug 29th 2011
     
    Panels are coming in at about £1/Wp now, have inverters dropped much?
    •  
      CommentAuthorJSHarris
    • CommentTimeAug 29th 2011
     
    The same is true for all schemes that attract government grants or payments. The industry makes damn sure that they get to include some esoteric certification requirements into the legislation so they can increase their profit margin. I've yet to see a bit of legislation like this where there isn't an element of profiteering involved. MCS is just one of the latest ones, one that is seemingly already being looked at because of the way it's being misused by some.

    What I would like to see is a means by which a competent amateur (as in someone not doing it as a business) can gain the required certification qualifications at a reasonable cost. I looked into this when Part P started to impact on DIY electrical work, but found that it was pretty tough for someone reasonably competent (but not in the trade) to get the required qualification. My idea was that I'd get qualified (one of my degrees is in EE anyway) then both look after my own electrical work and offer a free inspection service to any other competent DIY'er.

    Similarly, I'd love to do the same for solar PV installations, and maybe wind systems too, but it seems that hurdles have been deliberately put in place to try and prevent people doing just this. There's no safety argument for this, as presumably all qualified individuals have to be deemed to work at the same level of safety awareness.
    • CommentAuthorGavin_A
    • CommentTimeAug 29th 2011
     
    Posted By: SteamyTea
    Posted By: Gavin_Asteamy tea - separating the systems out would mean the PV system didn't benefit from the cooling effect, so I'm not sure where you're coming from with that idea


    Think JSH is really asking the same questions. But if the HP is not running much in the summer, then where is the advantage of cooling the panel in winter.
    Don't get me wrong, I like the idea, just think it is a bit complex for little or no gain, and at that sort of money you could buy a lot of insulation.
    I would have to see real operational data as well as manufacturers data before I could recommend that. Is there any real data yet?

    PV performance increases don't stop at 25 degrees, so a cooler panel in winter will still perform better than an uncooled panel (upto the point at which the cooling results in ice forming on the panel).

    On days of full sun all day in summer, then I'd think the heat pump would only operate for a relatively small part of that time to supply hot water requirements for a house. However, these days are relatively rare, and the majority of the time in this country we only get a few hours of full sun, so I'd think that on average through the summer the heat pump would be operating maybe 50% of the full sunlight hours, during which time it will be improving output of the panels by 15-20%, and the heat pump efficiency will also be maximised even compared to an ASHP. For the rest of the year, the proportion of sunlight time the heat pump would be operating would increase.

    Manufacturers are claiming around 20% increase in annual output from the PV panels, which I can see being possible in some circumstances (eg some of the systems seem to have either larger hot water requirements or goundloops for interseasonal heat storage. I'd expect somewhere in the 10-15% increase in annual output to be more likely for a family home.

    The increases in performance of the PV is only one part of the story though, with another side being much higher COP's than ASHP, particularly for the water heating side of things, and the potential to be combined with a much smaller than usual ground loop to supply heat at night instead of/as well as the panels.

    The 3rd aspect being that if combined with a decent sized thermal store, most of the heat energy can be produced when the panels are generating power, so you're not going to be paying for that energy source. Obviously you could achieve this with an air or ground sourced system combined with PV, but then you'd not be getting the additional 10-20% electrical output from the panels which alone could well supply maybe 1/3 of the heat pumps electrical requirements.
   
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