Panel efficiency: Why does it matter?

[MCS Renewables]

We have two similar systems with identical roofs and identical inverters and wired exactly the same way even the lengths of cable and routes are similar .



On the left hand side are Moser Baer modules and on the right hand side are Sanyo modules.

The MB project has been in since May 2010 and just about exceeded our annual solar prediction.
The Sanyo project has been in since October 2011.
The Sanyo beats the Moser every day, sometimes doubling the generation figures.

The Moser system was a lot cheaper installation but the additional FIT returns and import savings with the Sanyo will easily justify the extra cost.

Also Moser is an unknown manufacturer whose long term position is unknown as opposed to the Sanyo corporation.

The Moser Baer customer wishes he had Sanyo modules now.

 

[SolarCity]

Excellent comparison, thanks for the info.

Getting such an accurate example to judge performance is rare so they're extremely helpful.

Our Sanyo installs also all appear to be outperforming the other panel installs.

 

[pwboston]

thats ideal conditions for comparison being next to each other, that proves it better than any program can come up with in reality as you can physically see it

 

[FB.]

We have two similar systems with identical roofs and identical inverters and wired exactly the same way even the lengths of cable and routes are similar .

View attachment 10428

On the left hand side are Moser Baer modules and on the right hand side are Sanyo modules.

The MB project has been in since May 2010 and just about exceeded our annual solar prediction.
The Sanyo project has been in since October 2011.
The Sanyo beats the Moser every day, sometimes doubling the generation figures.

The Moser system was a lot cheaper installation but the additional FIT returns and import savings with the Sanyo will easily justify the extra cost.

Also Moser is an unknown manufacturer whose long term position is unknown as opposed to the Sanyo corporation.

The Moser Baer customer wishes he had Sanyo modules now.

The comparison is valuable - and appreciated.

Could the Sanyo's extra performance mostly be due to the dull winter days, where its extra technology would be expected to give it an edge.
It would certainly be interesting to see how much different the two systems are, after a whole year - in terms of total output (especially seasonally-analysed) and also the output relative to the cost of the system.

 

[Chris Nunn]

Some further thoughts on comparing modules using PV*SOL; Here’s a nice tip to look at when comparing modules or inverters. The trick is to combine the PV*Sol graph function and a spreadsheet. Here’s one I’ve made to show the difference in module part load efficiencies.



You could then include comparisons at different temperatures or for modules with a different temperature response. PV*Sol has a lot of hidden depths which the German translation doesn’t always immediately reveal. The manufacturers load the raw data up into the PV*Sol database to make it easier to analyse. If a module even has one letter or number designation different then there is a separate entry for it.

 

[SolarCity]

Nice tip. I wonder if anyone has any spare time on the hands and fancies showing a graph of all the popular makes?

 

[Del Boy]

Solar Centre: Desert Knowledge Australia

Solar Centre - Desert Knowledge Australia

I know not the same as UK but Sanyo consistently outperforms kW/kW installed of mono and poly equivalents, even during their winter months.

I think it's all a matter of price/performance ratio. Personally, I'd definitely pay 30% more for Sanyo even if I had the roof space and if it meant you could fit 8kW plus on instead of 4kW then it should make a similar % return too but for more initial investment. As for Sunpower, they are more efficient panel wise (not cell wise, as they have bigger panels so less frame per total area) but the co-efficient of temperature put me off.

@MCS Renewables, thanks for posting that info, backs up my original thoughts... would be interesting to see if this continues in the summer or if the Sanyos pull an even bigger margin.

Cheers,

Del Boy

 

[moggy1968]

That's interesting. I wasn't aware that the panel was any thicker to be honest.

Sanyo are 35mm wide, most others are 45-50mm. so sanyo are actually thinner in terms of frame depth. Does anyone know what the actual face thickness is compared to others?.

looking at the graph kindly produced above it would seem At higher irradiations the Sanyo advantage is less, but I beleieve their voltage drop due to high temperatures is less, which may explain the Australian findings, and goes in the face of the thicker panel argument.
The graph would appear to reinforce what most of us have said that it is their low light perfomance that sets them apart.

 

[Del Boy]

The frame is 35mm wide but I'm not sure if the panel itself is thicker or thinner?

One thing I didn't mention is that the Desert Centre has these ground mounted, so they will all be cooler than mounting them on our roofs.

It's summer over there (if you click on the temp it shows ambient of 32 degrees this week) and the Sanyo's this week have been about 15% better than the poly and monos which have been almost exactly the same. When it was winter I remember it outperforming them about 15% too.

When I looked at the low irradiance figures on the Sanyo and some RECs, I noticed the difference was hardly anything, on the 240W panels it's 45.9W vs 45.56W, so I can't help thinking it's not low light. Also in low light the power output is low, so if you are getting 20% better with Sanyos during low-light hours, you aren't actually getting much extra for the whole day as the majority was generated around midday. This can be seen quite easily on the Desert Centre, early morning and late afternoon the panels are much a muchness.

@MCS Renewables, have you got the data online? If it's SMA then it'd be great to see it uploaded to a public SunnyExplorer.

Just had a look on pvoutput.org

These two are close to each other... both in Oxford, is Sanyo (South-West) vs Schott (South)... the Sanyo's have outperformed the Schotts despite the orientation disadvantage by 17%. Also worth noting that the days when it outperformed are sunny days.

Compare - I hope that link works, should compare "My Power Station" to "Sims Solar", neither are mine so thanks to the guys who have uploaded this.

Please note the data has been normalised so you are comparing kwh/kwp, so the installation size doesn't matter (although the Sanyo is smaller and has generated more!)

Be interested to know everyone else's thoughts.

Cheers,

Del Boy

 

[Mark42]

This is fascinating. I have just realised I am in the perfect position to run such a comparative test. I am installing two 4kW arrays on my steel barn, South-facing roof, size 20m x 4m, 15 degree pitch, two rows, 16 panels left, 16 right, 200mm gap in the middle for connections and downleads.

2 x Diehl 3800S Inverters, two meters, exporting to my two phases. (My house is unusual in having a 2-phase 2 x 240V supply. It’s absolutely ideal for a comparative trial: two completely electrically-separate 4kW systems on the SAME roof.

BUT I have just taken delivery of 32 ‘cheap’ HJ-Solar HJM250M-32 panels:

http://www.swithenbanks.co.uk/product_uploads/13202300511.pdf

So what I’d have to do is sell 16 of these (Or maybe return to the supplier). Does anyone want 16 x 250W HJ’s at £170 + VAT each? (With the correct Schuco mid and end rail clips included). Collection Diss, Norfolk, or pay Palletways for delivery. I have a forklift and can load.

And is there a big dealer/wholesaler out there who will supply me with 16 x Sanyo 250W panels at a reduced price in exchange for the data raised – if it’s true that Sanyo knock the spots off other panels in the British climate, it would prove the hearsay for once and all, so imagine how many more you’d sell! Everyone wins.

This will have to be quick though. I’m installing next week.

Anyone interested?

Mark

07860 346536

 

[mdovey]

Maybe drop Sanyo/Panasonic a line - they may be interested in sponsoring such a reference site?

 

[Mark42]

Maybe drop Sanyo/Panasonic a line - they may be interested in sponsoring such a reference site?

Yes, good idea, but I'd rather it be 'just me' - ie completely independent, since, if Sanyo 'wins', you can be sure someone will alledge a conspiracy.

And I doubt I'd get an answer in only a few days. 3 March is fast approaching!

 

[Mark42]

I've been thinking: The only difference between the two arrays would be very slight voltage drop differences, and hence losses, in the (long) dc cable, due to different voltage/current characteristics. But this can be calculated as a percentage difference and applied to the readings. It will be very small. Apart from that, the test will be exactly equivalent.

I really want to go for this. Game on!

 

[Markc]

Good luck on getting Sanyo 250's currently at a reasonable price let alone a cheaper price. But I agree it would be a truly fair comparison give the inverters are the same. Having several Sanyo systems in place our own records show they are out performing similar systems of the same size but we could be deemed as being bias!

 

[FB.]

Good luck on getting Sanyo 250's currently at a reasonable price let alone a cheaper price. But I agree it would be a truly fair comparison give the inverters are the same. Having several Sanyo systems in place our own records show they are out performing similar systems of the same size but we could be deemed as being bias!

But the big question is: are the Sanyo panels giving an increase in performance which is proportional to the total installaiton cost?

With a 4kW Sanyo-panel system likely to retail for around £12500, a 4kW "mid-range-panel" setup around £11000 and a 4kW "cheap-ish-Chinese" setup for around £9500.

Does a Sanyo outperform a Chinese system by the 30% price differential, or outperform equivalent to the 15% price differential over a "middle quality" system?

That's the big question which we're all eager to find out. Winter yields only a small amount of our annual total PV, so we need to see a whole years generation stats to make reasonable comparisons.
Late this year I think that autumn 2011's mad installation frenzy will have got us enough systems on rooftops to start giving a good idea.