Price of Solar Panels v's Tubes

BMD

Registered User
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133
Hi,

What would be the average price for 6m of solar panels compared to 6m of solar tubes?
 
Not sure about price, but solar tubes seem to perform better than panels especially in the darker winter months when there is less daylight hours, from research i have been doing especially into Kingspan as they are designed in Ireland for an irish climate.

However if you are in to looks and the front of your house is facing south(as panels/ tubes need to face south to get most daylight of the day), you will more than likely opt for the panels as they do not rise as much from your roof as tubes.
 
check out how the panels versus tubes survived the artic conditions last winter too
 
Mum2009

any links to the comment ? I have tubes and previosu years have got great results but this year to date not good at all, have had someone in just before christmas to fix my heating system, timeclock etc. so not sure if they might have done something to effect the Solar HW, but as it was nov didn't get a chance to see if all was working afterwards.

I am not getting any real hot water despite the really good weather, so htink either something wrong/accected by this other work, or something wrong with the panels.
 
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A few possibilties here - either the plumber knocked something off, or you had a frost that damaged and drained the system, possibly the pump has seized, or any one of a few eletrical things initially spring to mind.

Most tube systems don't have a heat dump when they should have. This means that summer the system overheats, damaging the antifreeze. However, usually there would be a phase during which you would hear air gurgling in the pipes.

You need to look at the controller and see what temperature your panel is reaching. It should usually be 6 to 10 degrees hotter than the bottom of the cylinder. If the panel is at 80 and the cylinder is at 20, then check the flow meter and see if the pump is running.

On the other hand, if the controller is making no sensible readings at all, you may have a damaged probe, bad connection etc.

Either way, I think unless you are a very competent DIYer you're going to need to call out a solar installer to remedy the situation. PM me with your approx location if you want the name of someone in your area.
 
you need to remember to install flat panel collectors you need a roofer to fit them with tubes you dont.
 
Thanks Slim, just makes it easier for people to find such information in future. No one would think to look in a thread on solar panels for tips on reducing electricuty useage.

Back to the topic, I got a quote a couple of years back for tubes. The company I got out supplied both, but strongly recommended the tubes as they said they worked better in our climate for a longer period of the year. [broken link removed] are the guys I had out, they include a comprehensive comparisson of the various panel types on offer [broken link removed].

I didn't go with it in the end as the return on investment was too long in my case to make sense.
Leo
 
going back to the price thing, as a guide I have recieved the following quotations in the past month:

30 tubes plus 300 litre cylinder including expansion vessel and fitting - €4,650

40 tubes plus 350 litre cylinder including expansion vessel and fitting - €5,100

both for the same project, in which the installation was quite simple and runs to tank from collector were short. System proposed seems decent and is on the HARP database.


www.studioplustwo.com
 
No matter what the price is, ensure that the quality of both the product, fittings and the overall installation are upto to spec. I have on an ever increasing amount of call outs to problem systems due the poor installation and poor materials.

Some things to look for are:

Quality of the cylinder. Many stainless steel cylinders are of poor quality. They may well come with a long warranty however, if the property is not fed from mains water, this is a get out clause for the manufacturer and is an increasing problem.

Installers using 1/2" copper (sometimes plastic coated and not removed). This is a fire hazard. 1/2" copper is just about ok, but sometimes difficult to achieve the required flow rates to achieve an effective system. Always try to install in 3/4" for pipe runs of upto 25m in length and 1" above that. Always try to use factory insulated stainless steel corrugated pipework such as Armacell Duo Solar and their fittings kit.

Installers not using the correct insulation on pipework. It must be High Temperature rated otherwise it is a fire hazard. Class O is not acceptable.

Installers not installing a heat dump where required. The system will stagnate and poor performance will arise and more frequent service costs.

Installers not installing a solar discharge vessel for safety. This is when there is a component failure or system overload and the pressurized system may blow off. If not into a contained area, a homeowner could be permanently disfigured from scalding glycol exiting the system.

Cheap products used to bring the pipework from outside to inside of the roof. This can lead to eventual roof leaks.

Tie down bolt kits used. These are normally over-tightened and rely on a rubber washer to determine the waterproof integrity. Installers normally over-tighten the tie down bolts, leaving to no movement between kit and roof covering leading to cracked slates/tiles and also rubber washer will eventually perish. I personally prefer the sloping roof kits which are independent of the roof covering.

Inferior glycol used. Glycol that comes factory mixed is always best. Ones that must be diluted are a no no. The integrity of the homeowners tap water cannot be guaranteed for minerla content and with constant separation of glycol, the integrity will not last. Also how much water is too much or too little when they mix on site?

All of the above items have an effect on the overall price, so when comparing various installers pricing, make sure they are all singing from the same hymm sheet. You do not want to have to pay for the installation twice as when installed correctly you will have years of trouble free hot water.
 
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