Issued 5th May 2009 - How Efficient are Your Solar Panels?
I hope thatyou don’t mind me writing to you on this issue? It is a question that I get asked a lot by customers and in my experience it is not something that a lot of installers are able to readily answer. Most people are of the opinion that evacuated solar panels are more efficient than flat plate panels, in most cases this is correct but it should by no means be considered a given.
During my travels I have come a across a lot of good and bad panels that are being installed across the country, the most disturbing thing that I see is low quality evacuated tube panels with outputs LOWER than most flat plate panels being installed for customers how believe that they are getting a more efficient product.
Solar panel outputs are measured in terms of kilowatt hours per square meter per annum or kWh/m2/a, as a rule of thumb all decent panels should be greater than the following values
Over roof flat plate panels: 510 kWh/m2/a
Integrated flat plate panels: 550 kWh/m2/a
Evacuated tube panels: 600 kWh/m2/a
I’m not going to name names, but I have seen evacuated tube panels with outputs as low as 410 kWh/m2/a which means that the lowest quality flat plate would give approx 25% more heat than it.
This is why it is important to know what kind of output your solar panels are capable of, make sure that you are comparing the square meter output figure and not the entire panel output figure.
Of course I am not giving you this information entirely out of the good of my heart, as one of the largest importers and distributors of solar panels in the country I am trying to promote our top quality products at the same time, here is a list of the outputs from our main sellers.
AF24 Over roof flat plate panels: 555 kWh/m2/a
WF24 Integrated flat plate panels: 577 kWh/m2/a
CPC6 Lite Evacuated tube panels: 651 kWh/m2/a
All of our panels come with a 10 year warranty so if you don’t have to worry about reliability of the panels once they have been installed and you have long left the site.
Issued on 5th May 2009