What panels are best value

[Mark42]

… Japanese panels maintain 100% of "as-new" performance for the 25-30 year lifespan; flawless performance.
Chinese panels lose 5% of their remaining output each year (as opposed to the claims of 1% loss per year). …

These are serious allegations, and VERY interesting if true. What is your source of information please?

Losses on the ‘guaranteed’ Chinese panels approaching the level alleged would be an actionable violation of the Sale of Goods Act in the UK. ie ‘Not as described.’

Today I started a real test, at my house in Norfolk:

http://www.electriciansforums.net/p...ide-long-term-real-world-test.html#post471778

 

[wstevew]

My Suntech Mono's are again over monthly target, By 25% this month and still 3 days to go and will be 40% over by month end if I add total kWh divided by 26 * 3.

 

[cjapeterborough]

Efficiency Leaders in Crystalline Silicon PV : Greentech Media

Looking at both tables of results the majority of the panels are all within +/- 3% of each other which in most cases is the manufacturing tolerances

If you look at the disclaimer at the bottom of the linked report it states:
Neither PTC nor STC account for all “real-world” losses. Actual solar systems will produce lower outputs due to soiling, shading, module mismatch, wire losses, inverter and transformer losses, shortfalls in actual nameplate ratings, panel degradation over time, and high-temperature losses for arrays mounted close to or integrated within a roofline. These loss factors can vary by season, geographic location, mounting technique, azimuth, and array tilt.

What all these tables show is a lack of cost per kw which is by far the biggest difference between the panels and not performance.

 

[mark_]

Vegelen,
Earlier you wrote about performance in cloudier or clearer days, where did you find that sort of information.

Could anyone explain or point me in the direction of some literature which explains what details provided by the manufacturer are key. For example when comparing two panels which are the most important factors to look at (eg peak efficiency etc).

Sorry im a bit late on this thread but I like the original poster would like to know more on panel selection.

 

[sedgy34]

Is there a 330w module sunpower

 

[danesol]

Given the lower feed in tariff I assume most are reverting to cheaper panels. How do we know which panels are best? Is there a list anywhere that rates PV panels. I have seen comments on this forum that says some panels are good and others are crap but it all seems to be a matter of opinion.

Best in what context ..................

Best in efficiency ??

Best in High temperatures ?

Best as they marry up with particular Inverters ?

Best as they produce the highest voltages ?

Best in Cloudy or Sunny Clear days ?

Best for the amount of roof space you have ?

Best for your chosen ROI ?

So - Yes you could look at specific specifications like generation per sq mtr and how efficient they are, but if NOT married with a suitable efficient Inverter, they could turnout not quiet as effective as you thought - IMO, its all about system design for each particular customer's requirements & their particular environment ( which in most cases you can do s0d all about ! ) and about the experience & knowledge of an Installer who has learnt up & above the components specs to deliver the best system for each individual customer

 

[FB.]

These are serious allegations, and VERY interesting if true. What is your source of information please?

Losses on the ‘guaranteed’ Chinese panels approaching the level alleged would be an actionable violation of the Sale of Goods Act in the UK. ie ‘Not as described.’

Today I started a real test, at my house in Norfolk:

http://www.electriciansforums.net/p...ide-long-term-real-world-test.html#post471778

Sorry I've only just seen this.

I was not saying that Chinese panels are inferior in perofrmance or durability.
I was making the point that an installation with Chinese panels could underperform and degrade faster than top-of-the-range panels, yet still give a very respectable payback.

My Chinese panels look to be on track to outperform SAP by 15% or so - so about 3400kWh per year.
In my area, Sanyo installations of similar facing and size are generating about 10% more than mine. Let's call it 3800kWh per year.

I would have had to pay £12000 for Sanyo, to achieve annual generation of 3800kWh. That's £3.16 of cost for every kWh generated.
I paid £9000 for Chinese and look to be on course for 3400kWh. That's £2.65 of cost for every kWh generated.

So, at the moment, it looks as if my Chinese panels give about 20% more output for every £ spent compared to Sanyo.

So just because they aren't as good, doesn't mean that a lower price hasn't fully discounted it.

 

[FB.]

Vegelen,
Earlier you wrote about performance in cloudier or clearer days, where did you find that sort of information.

Could anyone explain or point me in the direction of some literature which explains what details provided by the manufacturer are key. For example when comparing two panels which are the most important factors to look at (eg peak efficiency etc).

Sorry im a bit late on this thread but I like the original poster would like to know more on panel selection.

Just as important as the panels, is having a system which is well-planned and well-installed. Irrespective of price; a well-planned/installed system with Sharp, Suntech or Kinve panels could far outperform a poorly-planned system with Sanyo panels, even though Sanyo panels are generally superior.

So don't just base a decision on the panels; base it on well-matched parts and an installer who knows what they're doing.

 

[mark_]

FB, I totally agree with you that panel are not the be all and end all of a system. I am just starting looking into PV systems and started with the types of panels. I will also be looking at different types of invertor and how they vary.

You wrote above:- "Best in Cloudy or Sunny Clear days ?"

Where would you find such information?

 

[Vegelen]

Check your private messages.

 

[Earthstore]

Is there a 330w module sunpower

There is a 327 and a 333 module, if you would like to know more PM me.

 

[provr6]

I don't see how anyone can estimate a particular panels performance deteriation in future. My biggest concern regarding panels performance is water ingress.

 

[solarcat]

I don't see how anyone can estimate a particular panels performance deteriation in future. My biggest concern regarding panels performance is water ingress.

Don't think we need to worry too much about this.
Crystalline PV panels have been manufactured more or less in the same way as they are now since the late 80sand manufacturers are still happy to offer good warranties. Unless the glass or the back sheet of the panels break, water ingress is extremely unlikely as the cells are encapsulated and laminated.
Companies like Kyocera, Helios Technology, Solarworld have all been around for ages, all that has changed about their modules is the efficiency of the cells and the format.

 

[Glen Powell]

I think moisture entering into the system is a very important factor, I always look in the corners where the glass meets the frame on some panels there is a large gap where water can collect and enter the panel.

The glass quality is very, very important as over time it may tarnish or discolour making it harder for the light to penetrate, the make and design of the connection box, some may let humidity in which over the years will corrode the terminals. Sealants used to ensure it will still be sealed after 10years.

Why do some manufacturers insist on using stainless steel screws on aluminium frames, I am sure the two metals react causing corrosion over the years, but if it is all time tested then all must be OK.

Thats my basic take on panels anyway before going into technicalities of the Cells

 

[solarcat]

I think moisture entering into the system is a very important factor, I always look in the corners where the glass meets the frame on some panels there is a large gap where water can collect and enter the panel.

The frame is not intended to provide water tightness, it is there for mechanical strength and ease of fixing (so that the pressure applied to the panels by the fixings does not affect the glass).

The encapsulation and lamination process are there to provide water tightness.