Why are all the components for a solar system so expensive ?

[Sharp Point]

The solar thermal roof we developed was using pull extruded grp with all interlocking strips with a heating matrix behind it - it was so strong you could use it for solar walls and as a demo I drove my Landrover over it. Thats what I am using this time with the left overs for a garden office.

Ooooo, sounds interesting. Any piccies?

 

[Rob Foster]

This was 3-4 years ago and that year is on a computer that got locked out it will be going to the experts as I need some records from it anyway then you can see no problem. I will see if tere is a web link to it later. Now in your experience how often do solar systems need the fluid topping up ? I know that some installers make perfect systems but many do not so - how often and how much ?

 

[Rob Foster]

Ok I found a reference to it 'versatyle solar' on google images two pics 1.outside view 2 the heat collector - we built a fully operating set up with about 30 m2 collector with the full solar cylinder and control kit using Sentinel R100 - which tastes uck when you get airlocked but really does the job. The system still operates today. Am I boring you ?

 

[ShaunCorbs]

Ok I found a reference to it 'versatyle solar' on google images two pics 1.outside view 2 the heat collector - we built a fully operating set up with about 30 m2 collector with the full solar cylinder and control kit using Sentinel R100 - which tastes uck when you get airlocked but really does the job. The system still operates today. Am I boring you ?

this?

 

[Ric2013]

Looks very inefficient, but quite pretty. No data on the Versatyle site. Tested for 98 years. Really? Also seems to use a heat pump. So it's a thermodynamic panel then (i.e. a not very good ASHP)?

Should you install thermodynamic panels on your home?

 

[quality]

No it sounds interesting

 

[Rob Foster]

yes thats the project - the roof material was certified cant remember by which uk body - the heat gathering was not as efficient as some set ups but is very robust and all the components cheap and off the shelf

 

[Ric2013]

I'd just want to see data is all. The website is currently under construction and the collector shown looks much like an underfloor heating system, or the very basic collectors made from copper tube soldered to a metal plate (which work very reliably, but are nowhere near as efficient as the more technical and modern collectors).

 

[Rob Foster]

In order to understand this system I need to explain the roof came 1st it is quite innovative and can be any colour and with any printed finish. It is supplied in artic lorry length strips which simply slot over and interlock its light and easy to shape. The solar bit followed on when my company where asked to produce an addition to the original roof system. Hence v solar. I can dig out the actual test results over 6 months if anybody wants to know.

 

[Ric2013]

Well, yes please. It looks like a matt black surface which would be extremely effective in direct sun on a hot day and when a low temperature and low delta T are required. Could be very good for heating the water for a swimming pool. But the high emissivity surface looks like it would radiate a lot of heat so would never reach a high temperature, nor work well in winter. At this point, if you're having to add a heat pump, it starts to look less efficient than an array of evacuated tubes or modern flat panels, or an ASHP.
Looks nice, but then it's just what we're used to. I'm sure people used to say that slate roofs look industrial and lack the charm of thatch and how we are ruining our heritage by using slates in the name of progress. Perhaps conventional solar panels are much the same?

 

[Rob Foster]

Yea the roof can be printed to look like slates, tiles -any sort or even a football club pantone colour. Its also really strong and some went on a church roof because its so difficult to prise off and angle grinders are needed to cut it. I experimented with several colours to see which absorbed the most heat and also finishes- there was an early version which had foot grip section embossed on it - that really took up the heat.
As you say its no good when it rains but the performance in winter sun was good too - I will get out all the performance logs later. Its strong enough for a solar wall - kids can kick a football at it all day long.

 

[Rob Foster]

hi ric2013 I have spent a happy 2 hours going over records from 5 years ago - when I have finished being nostalgic I will post some results - there in notebooks by day, date, weather, outside temp,
rtn temp of solar fluid and domestic hot water temp ! it might take a while.

 

[Rob Foster]

Ok I have a mass of paperwork here all tabulated in 2013 Jan- June
The roof was as outlined before a simple solar thermal collector. We did have in the end a good set up all with solar stuff, pump, clever box etc to make it perform ( I have found some pics) . Remember this was not about a high performance panel but a large roof collecting energy. The aim was to get a domestic hot water system up to usefull temps ie 55c +
We got a 140ltr cylinder up to 46c and beyond many days in 2-3 hours with outside shade air temps of 17c.
Then if it fell short the heating system could top up - if anybody is still keen to know more then I will do some more info

 

[Sharp Point]

You say up to 46 degrees, what was the temp of water in the cylinder before the data was collected. What sort of cylinder was used... twin coil or retro fit immersion coil, if the immersion coil was used, was this in conjunction with a destratification pump. Where was the cylinder temp sensor positioned on the cylinder.

 

[Rob Foster]

We are off n a business trip early tomorrow, I will collate the figures soon - back at weekend