Its is good to see some more technical discussion of this technology, even without firm performance data. At the other end of the scale, how is this equipment going to avoid icing and what defrost cycle is available?
Actually I reckon that where used for water heating only at least it doesn't need a defrost cycle, as it's probably simpler and more cost effective to just switch to immersion if required once the COP becomes lower than 1:1, then rely on the sun to defrost the panel - this is one advantage these systems have over ASHP where the sun will never defrost the ASHP while outdoor air temps are low, whereas I'd expect the sun would be able to defrost these panels fairly quickly even in -10 ambient air temperatures, which I've certainly seen happening with PV panels.
The running costs element is critical to its viability. Normal Solar Thermal has zero costs for energy production and pretty low running costs - a fluid change every five years and a pump if you are unlucky during it's lifetime.
not entirely true - the electricity to power the pump can easily cost £5-10 a year depending on the set up, efficiency of the pump etc. Unless it's a PV powered pump, or I guess if the customer also has solar PV installed.
There is a lot of hard work going on with DECC to make normal ST viable under the proposals for the RHI.
snigger... the same numpties who killed the solar thermal industry immediately the tory government got into power by pulling the plug on the previous grant scheme then taking 3 years to fail to implement RHI? That's not my definition of hard work to make ST viable, quite the opposite, but yes maybe they will eventually come up with something that makes it viable again.
I think the one thing the opinions expressed in this thread shows is the true market for appropriate use of this equipment IF it's performance can be validated is very very small.
I agree that it should be a niche product,but I'm not sure I'd agree on the size of the potential niche being 'very small'.
all new houses by 2016 ought to have the sort of low energy requirements that would make this sort of technology potentially viable for both heating and hot water purposes as long as the government doesn't water down it's plans any further (ok, maybe only the smaller houses / flats, with ASHP being more suited for larger houses). That's a 100,000 houses a year potential market for both water and space heating, or for water heating alone.
There's also around 500,000 homes that are all electric heated, where this would almost certainly be a cost effective alternative for the water heating side of things at least (if installed at a reasonable price), and surprisingly, that number has been risking over recent years due mainly to the number of flats / 'studio apartments' being built with such low heat demands that they're opting for all electric heating to save the expense of a wet gas heating system. I'd think that many of these stuido apartments could well be candidates for themodynamic panels to be viable cost effective alternatives for both water and space heating, where there's only 1-2 rads and low heat requirements due to only 1-2 external surfaces with reasonably high insulation values.
I'd also think this could be a particularly viable option for water heating only for those with PV installed where the running costs could be close to zero if the water is set to heat only during the day.
Use in conjunction with other technologies means it would need to to be compatible with a multi-coil thermal store or hot water storage vessel, not just a dedicated tank. If it is not compatible, you are possibly in to a two tank design, with all the space implications that entails.
that entirely misses the advantage these systems have over solar thermal in that they do not need a secondary heat source other than an immersion for the very few days of the year when the system can't operate due to extreme low temperatures. So no they don't need a second coil to be combined with another heat source.
