Skip to main content
Observer Ethical awards Winners 2011

YouGen Blog

Manufacturer's claims for solar PV performance stand up to scrutiny

Posted by Gabriel Wondrausch on 31 May 2011 at 9:20 am

Offering our customers the best products available is a key commitment for SunGift Solar, and thorough research and testing of products to ensure that they stand up to manufacturer’s claims is part of that. We always try to visit manufacturing plants and company head quarters and meet with the key people involved to see for ourselves what they are all about.

As part of this last commitment I went to Valencia earlier this month to visit Siliken whose solar PV modules won 2010 Photon Test, producing more kWh per kWp than any of the other 47 manufacturers tested.

My visit to Siliken started with a tour of their manufacturing facilities by their quality manager Vicente Martin Mangales. The timing of the visit was ideal. They have just installed two brand new automated production lines.  The new equipment improves the efficiency of the plant and increases the output to 200 modules per shift.

Vicente took us through the whole process from cell to finished module. Having seen a few module production lines now I was pleased to see the attention to detail and levels of quality control in place.  

Making PV modules is a delicate process with a lot of variables, a bit like baking a cake.  As a result, you never know exactly how efficient the modules you are making will be. At Siliken the lines were supposed to be producing 245w modules but the majority coming off the lines were in fact over 250w modules.  Most of those being sold as 245w modules have an output of 248-249w, so many lucky customers will have significantly more power than they bargained for!

The module manufacturing plant visit was followed by a visit to the Siliken laboratories, five minutes down the road, where I was met by Ana Belen Grau Margues, the product laboratory  manager. She is one of the most passionate people I have met in the renewables industry and someone who clearly really enjoys her role of attacking and improving PV modules!  I was shown a few of the new products that are currently still under wraps and also the testing process which the modules and components go through. 

It is amazing how much work goes into every component that makes up the module. 80% of the work carried out in this laboratory is improvement work to increase the performance of all the separate components.

The rest of the time they test the modules to the limits, including climatic chamber tests where the modules are exposed to extreme and rigorous testing. Testing scenarios include 85 degree heat and 85% humidity for a total of 1,000 hours whilst under electrical load.  In some climatic cycle tests, modules are taken from 85 degrees to 41 degrees in 6 hours, and then repeated 85 times whilst under current. 

There is then a visual, power, electroluminescence, wet and dry inspection of the module. These tests are usually repeated several times!   

Stress and load testing takes place where 5,600 pascals are loaded onto the module then all the previous tests are carried out to check the performance is not compromised. There is also a test rig where shading simulations are carried out to test for hotspot and cell characteristics alongside TUV reference cells (independently tested cells). 

One of the main reasons that they are able to offer the linear warranty on their modules as well as the positive power tolerance is the strictness off the continual testing process.

A huge amount of work is being carried out on the EVA encapsulate which encase the cells in PV modules.  This is a product essential to all PV modules that is hugely important to the efficiency and longevity, as any weakness in this encapsulate will lead to increased degradation & could lead to the cells being damaged by the elements.

I then went to the Siliken head office where we were met by Alvaro Navarro Paulo, the product engineering manager who is one of the most technically knowledgeable people I have met in the industry.  He really is a fount of knowledge on all things solar PV, and someone I feel very grateful to have met.  Unfortunately for him he will probably be my first port of call for the most demanding technical issues!

By this time we were running rather late due to my incessant questioning, but Luis Azorin the international sales development manager took us to a local restaurant where we had a very nice lunch and discussions about both SunGift Solar and Siliken. Back at the HQ Luis gave me the full details of the company its founders and its future plans. 

The company's strap line, "Innovation Experience" is extremely fitting.  Siliken is still a fairly unknown brand here in the UK but it has been manufacturing PV modules since 2001. It is active in over 20 countries worldwide and following the Spanish PV boom of 2008 it has continued to show strong growth worldwide with four manufacturing plants in the EU and USA.

I was very impressed with Siliken and I can see why their modules have come 1st in the recent tests carried out by Photon. Everyone I met was extremely kind, passionate and above all knowledgeable.

I personally learned a great deal and am extremely happy to be able to offer such a fantastic product to our customers.  There is currently no other product we can offer that has such high yields at that cost, where the quality is outstanding.

About the author: Gabriel Wondrausch is founder and director of SunGift Solar, which installs solar thermal and other renewable energy systems in the South West of England.

If you have a question about anything in the above blog, please ask it in the comments section below.

Like this blog? Keep up to date with our free monthly newsletter


2 comments - read them below or add one

Gilly Jones

Gilly JonesComment left on: 26 September 2011 at 1:42 pm

You can find a table at the bottom of the blog Comparing the performance of solar PV panels

report abuse


peter.orpinComment left on: 26 September 2011 at 12:23 pm

I have read your review concerning the testing of various panels. You say the results can be viewed in the table above but perhaps I am such a computer incompetent that I did not see the table. Where should I look please?

report abuse

Leave a comment

You must log in to make a comment. If you haven't already registered, please sign up as a company or an individual, then come back and have your say.