PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world test.

[Mark42]

Having been confused and irritated by the conflicting stories I heard about the relative merits of ‘expensive’ versus ‘cheap’ PV panels, I decided to find out the truth for myself.

I have just fitted an 8kW installation on my shed roof, comprising one 4kW array of 16 x £177 Hengji Solar HJM250M-3232 panels, and one 4kW array of 16 x £343 Sanyo HIT-H250-E1 panels.

These are run via two totally separate, but identical, electrical systems, from a 4-core 10mm SWA DC line into two single-phase Diehl AKO Platinum 3800S inverters, feeding into the two AC phases via two Landis & Gyr PV30-108 generation meters, mounted side-by-side for easy comparison.

These two arrays, mounted side-by-side on the same South-facing roof, will give an ideal and un-arguable comparison. No sales BS, no hearsay and guesswork, just clear meter readings.

I was trained as a scientist. I perceive the world through scientific eyes. And I like experiments. Game on!

It will take a year to give an accurate answer, since the characteristics of both makes may result in one out-performing the other under certain seasonal conditions. Day length, temperature, light intensity variations, and so on.

This will be most interesting. I will contact the media, and both manufacturers in due course.

Obviously the long-term economic benefit of either system needs to be calculated with reference to the typical retail installation cost to a customer. Can any PV professionals on here give me a guide please? What would the usual retail price difference for a 4kW install be please? I don’t need commercially-sensitive details, just a typical difference in price. If I said £4,000 would I be far wrong?

​

 

[babba]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

surely you must know what you paid for the installs..???

 

[Earthstore]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

What a fantastic experiment, there are so many permutaions that you could use, but this will prove something at least, in real terms.
As to the price differance, I would say a little less, around £3500, or somewhere around that figure.

Please keep us all informed as to how it is going, maybe the forum masters could give you your own post, that only you could post on, it would make it easy to follow.
But thankyou, and well done.

 

[Mark42]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

surely you must know what you paid for the installs..???

No, because it was a sub-contract deal tied in with other work, and my company supplied all materials which we ordered ourselves at trade prices. Plus for example we have our own digger and driver so did the groundworks ourselves. So I have no idea of what the 'real' relative costs would be if we has just said 'yes' to some cold-call PV salesman, in the manner of a ‘normal’ retail customer. Our total cost with a long SWA underground run was £16,339 inc VAT. I’m sure this is ‘cheap’ against retail for 8kW so is not a fair price on which to base the maths.

 

[Markc]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

Certainly is a very exciting experiment you have going there. May be open a straw pole now with the installers here on which "we" think will be doing the best. No other veritable other than panel. I like it.

So my vote. Should I stay loyal to what I've been told is the best or perhaps throw a swing vote for an unknown? What would I put my money on?

Sorry to say the sales BS is inbred now so Sanyo for me.

Please let us know how it goes. It's been some time since anything in the PV field has raised any form of interest but this certainly has for me.

Well done and good luck with it all.

 

[Mark42]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

What a fantastic experiment ...

Thank you for your kind comments, much appreciated!

Any ideas on how the experiment could be refined, or possible experimental error designed out, do say.

The idea of a comparative test only occurred to me at the last moment, after 16 of the planned 32 HJ's had already been installed. I immediately flogged the remaining 16 HJ’s on EBay, and ordered 16 Sanyos instead

Had it been planned from scratch, I’d have alternated HJs and Sanyos on the roof, and extended the wiring looms between alternate panels. But I think side-by-side complete arrays is good enough. Any slight difference in solar exposure due to position should not be statistically significant.

 

[screwdriver]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

I notice that there seems to be some shading in the photos, how where you thinking of creating fair test conditions? cut down the trees or swap the panels from one side to the other after a year? even the early morning late evening shadows could affect the results significantly!

 

[Vegelen]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

Q/ Why do people put expensive solar pv panels in poor locations, surrounded by trees with lots of shade potential?
A/ They act before they think.
To add insult to injury, they then install them with inverters not preferentially designed to work well in shady conditions.
You can install solar pv panels with world beating technology, but if you dont choose your installation location wisely you are wasting your time.
Such comparitive tests between 2 different solar panels are best done in installation locations with minimal shading issues to get a fairer test result.
Your photo's clearly show that you've got shading issues.
When the trees gain leaves in spring, it'll get worse.
People should think carefully where they intend to install solar panels, before putting them in, else they will be buying an investment that will underperform its optimum.
If shading is an issue, I would have installed the panels on Solar Edge Inverters, with 1 microinverter per panel.

 

[babba]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

Mad to think 12 months ago you would be looking at that kind of money for 4KW...You will be able to pick a pv system at the 99p shop soon..only messing...greg..now go back to bed...

 

[Mark42]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

I notice that there seems to be some shading in the photos, how where you thinking of creating fair test conditions? cut down the trees or swap the panels from one side to the other after a year? even the early morning late evening shadows could affect the results significantly!

Good question. There is young woodland South of the shed. I intend to pollard the trees that are close to the building this week, and keep the tops of the trees below the gutterline.

The tree density is equal on East and West so I expect both sides of the total array will be equally disadvantaged, as you say, in early morning and late evening.

It's good that there is a little shading, since performance under partially shaded conditions is an important design characteristic of PV panels, so should be included in the test.

 

[Mark42]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

Certainly is a very exciting experiment you have going there. May be open a straw poll …

Hi Mark. Thanks for the support.

I like the idea of a straw poll. Especially if there’s a quid on it

Maybe a dinner at a local pub in a year’s time, a nail-biting revealing of the results, and the ‘losers’ (who backed the wrong panel) paying the bar bill?

Cheers

Mark

 

[Earthstore]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

I can be a little harsh with some posters on here, but cash and dash is doing an experiment here, that all of us can learn from, as I see it, he has no personal gain from this and has funded it from his own pocket.
So be constructive, but support the guy, don't have a go at him.

Thanks

 

[Vegelen]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

It's good that there is a little shading, since performance under partially shaded conditions is an important design characteristic of PV panels, so should be included in the test.

Solar Panels love shade as much as a blind man loves not seeing the light.

 

[Markc]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

Hi Mark. Thanks for the support.

I like the idea of a straw poll. Especially if there’s a quid on it

Maybe a dinner at a local pub in a year’s time, a nail-biting revealing of the results, and the ‘losers’ (who backed the wrong panel) paying the bar bill?

Cheers

Mark

Now you're talking my language.

 

[Mark42]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

Q/ Why do people put expensive solar pv panels in poor locations, surrounded by trees with lots of shade potential?
A/ They act before they think.
To add insult to injury, they then install them with inverters not preferentially designed to work well in shady conditions. …

Really?

Well, a salesman told me that when you have potentially shaded conditions, you MUST buy the most expensive panels because they are designed to deal with the shade.

But I don’t care.

Because this is a real-world test, based on a real install, not a lot of unsubstantiated hearsay, or pushing of suppliers’ preferred systems.

Shaded or unshaded? Sahara desert or Norfolk? North or South or East or West? So what?

Here are two sets of massively-differently priced panels in a real location side-by-side. I’m not sure it’s been done before. Why not?

I’m expecting the ‘losing’ panel’s supporters to come up with all kinds or ‘Ah buts…’

eg ‘This is slightly shaded but ‘my’ panel would have been so much better in full sun.’ or vice-versa. Sorry, it’s all BS.

If anyone disagrees I suggest you also try an experiment so we can compare.

What’s the expression? Put your money where your mouth is?

 

[Markc]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

Come in guys we've all seen far worse on here than this. As by reading later posts the trees will be pollarded (is this a word?) and shade will then be minimal. Anyone who thinks they can install with zero shade is diludded IMO anyway. Minimal shade here and not a bad installation at all. Very well thought out. And in REAL life conditions.

 

[FB.]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

I would expect, at recent prices (before the current panic buying) a 4kWp Sanyo-panel system to retail for around £12.5k and an equivalent Cheap Chinese-panel system to retail for around £9k. With the recent panic buying, prices may be 10% higher if you can actually find anywhere with stock of the make/model which you really want.
Prices assume that the only difference is the panels.
Other perceived levels of quality sitting somewhere between the two extremes.

 

[SRE]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

What's the definition of the winner? The one that generates more in comparison to it's prediction or the most cost effective?

 

[Mark42]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

Such comparitive [sic] tests between 2 different solar panels are best done in installation locations with minimal shading issues to get a fairer test result.

Why?

You mean in the Sahara desert for example?

Clouds produce moving shade just as much as a tree branch. The UK has clouds sometimes.

A occasionally slightly shaded location is ideal for a real-world test.

 

[FB.]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

Really?

Well, a salesman told me that when you have potentially shaded conditions, you MUST buy the most expensive panels because they are designed to deal with the shade.

The recent snowfall gave me a chance to monitor the performance of my two strings of (cheap-ish) panels while some panels were covered (or part covered) by snow.

My conclusion was that a single panel which was covered by snow simply allowed its bypass dioides to channel the power around it, with a negligible loss of output to the others in the string, or to the rows of its own cells which weren't shaded.
One panel out of eight shaded seemed to result in only a fraction less than what I would have expected from the remaining seven panels.

However, diagonal shading across panels is very bad as the cells are arranged in lines (with bypass diodes often at the ends of each line). So if one cell in each line is shaded by a diagonal shadow, the whole panel is basically shut down. If the shadow - such as a telephone pole - extends diagonally across several panels, it shuts all shaded panels down. Any panel in the string which remains unshaded will continue to function normally. Clever orientation of the panels (landscape v portrait) could reduce the effect of shading by reducing the number of panels (or rows on a panel) in shade at any given time.

 

[Mark42]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

What's the definition of the winner? The one that generates more in comparison to its prediction or the most cost effective?

Good question.

I’m not in the slightest interested in predictions, only in results.

The ‘winner’ (if any) will be the panels which demonstrate a statistically-significant economic advantage, taking into account the whole-life cost of ownership. That’s why I need base retail costs.

I think a fair period on which to judge the result would be to use ten years as a basis for the calculations, extrapolating from one year’s data. My partner is a mathematician by training, so I’ll leave that stuff to her: statistical analysis is a black and unknown art to me.

 

[SRE]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

Our telephone wire runs diagonally across our array (issues with BT moving it) we produced 15% more than PVGIS and PVSOL suggested we should over a year. The wire is approx 250mm from the panels at one end and 400mm at the other. I'd expected lower than anticipated generation particularly as we have Sharp panels but I can't really complain about the impact shanding has had.

 

[Mark42]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

The recent snowfall gave me a chance to monitor the performance of my two strings of (cheap-ish) panels while some panels were covered (or part covered) by snow.

Thanks, FB, for your intelligent analysis. All most interesting!

 

[whinmoor]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

Interesting experiment. Looking forward to following progress. Could you provide links to the datasheets for the panels and inverter? Serious gamblers like to study form before putting down their hard earned cash ;-)
A few questions:

a) Could you tell us (roughly) where in the country this is happening?
b) What's the pitch of the roof? It looks pretty shallow to me - maybe only 20-25 degrees?
c) Will you intervene in any circumstances? Any cleaning planned? What if a flock of birds from the nearby trees mess all over one end of the array? Is it just tough?

 

[SRE]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

I think a fair period on which to judge the result would be to use ten years as a basis for the calculations, extrapolating from one year’s data.

Mmm for someone not interested in predictions I can't quite see how an extrapolation from one year's data can be accurate - how do you know what the ongoing rate of degradation will be. Maybe HJ panels will degrade quickly in year one but have minimal degradation from 2 - 10 years.

My money's on HJ by the way ..... not scientific in any way ;-) I've just got other things to spend my cash on than top of the range branded panels.

 

[FB.]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

Good question. There is young woodland South of the shed. I intend to pollard the trees that are close to the building this week, and keep the tops of the trees below the gutterline.

The tree density is equal on East and West so I expect both sides of the total array will be equally disadvantaged, as you say, in early morning and late evening.

I was also trained as a scientist, so don't think I'm being awkward when I suggest that perhaps your local climate tends to have more sun at certain times of the day, so perhaps one of your systems will be slightly advantaged. Also the panels will prefer to be running cooler, so those with afternoon sun may have a small loss of efficiency due to the temperature usually peaking around 2.30pm (well, that's typical for when it peaks here).
I'm in East Anglia and both my "gut feeling" and local weather station data/observations suggest that my local area gets slightly more sun (and slightly stronger sun) in the mornings, whereas lunchtimes often cloud-over and afternoons often have hazier sunshine.

 

[FB.]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

b) What's the pitch of the roof? It looks pretty shallow to me - maybe only 20-25 degrees?

That could put the quality of the panel's self-cleaning coating under test. The repellent coating alone might be a major performance factor unless the panels get a periodic cleaning (but on a realistic timespan).

 

[Mark42]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

Interesting experiment. Looking forward to following progress. Could you provide links to the datasheets for the panels and inverter? Serious gamblers like to study form before putting down their hard earned cash ;-)
A few questions:

a) Could you tell us (roughly) where in the country this is happening?
b) What's the pitch of the roof? It looks pretty shallow to me - maybe only 20-25 degrees?
c) Will you intervene in any circumstances? Any cleaning planned? What if a flock of birds from the nearby trees mess all over one end of the array? Is it just tough?

I’ll get links to the form sheets in the morning – going to bed soon

1. It's no secret: North of Diss in Norfolk. Approx N 52° 27’ E 001° 08’
2. Yes, it’s shallow. 15 degrees. Sub-optimal, but all panels equally disadvantaged.

1. In that scenario, I would clean the birds' mess off. Unless of course it was equally spread over both sets of panels, when it would be a difficult call

 

[Vegelen]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

Really?

Well, a salesman told me that when you have potentially shaded conditions, you MUST buy the most expensive panels because they are designed to deal with the shade.

What are salesman there to do? Sell

Don't always believe what they tell you.

I am currently monitoring 2 systems: Suntech v Sanyo Hits

Suntech monocrystaline panels are outperforming Sanyo Hits in low light conditions by 10-15%, but underperfoming significantly in bright conditions (40%).

The latter conditions are when you preferentially want solar panels to outperform in preference to the former, but the ideal panel would ideally be good at both, which most panels are not.

 

[Mark42]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

I was also trained as a scientist, so don't think I'm being awkward when I suggest that perhaps your local climate tends to have more sun at certain times of the day, so perhaps one of your systems will be slightly advantaged. Also the panels will prefer to be running cooler, so those with afternoon sun may have a small loss of efficiency due to the temperature usually peaking around 2.30pm (well, that's typical for when it peaks here).
I'm in East Anglia and both my "gut feeling" and local weather station data/observations suggest that my local area gets slightly more sun (and slightly stronger sun) in the mornings, whereas lunchtimes often cloud-over and afternoons often have hazier sunshine.

Bloody scientists: they always need to pick holes in each other’s hypotheses and experiments.

I love it!

That’s the way to discover the true reality behind false perceptions, and it’s what science and the search for truth is all about.

What you say is true: my experiment only applies within my local climatic conditions.

A more perfect experiment would be to repeat the exact-same set up in many different UK locations. But unfortunately my research budget does not run to that.

Perfection, as one so often finds in life, is an elusive phenomenon.

ps. I too have a gut feeling about this experiment, but I try not to think with my gut.

 

[Gavin A]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

It looks like the Henji panels have an Vmp of around 50V per panel, vs around 36V for the sanyo H series panels.

The voltage of the array relative to the inverters peak operating voltage can make a significant difference in the inverter efficiency - 2-3% sometimes, so for the experiment to be fair the panels should both have been at the same (or very similar) operating voltage.

You may be able to use the inverter's performance data to work out a correction factor to apply to remove the impact of this aspect of the design from the results.

 

[SolarCity]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

Well, a salesman told me that when you have potentially shaded conditions, you MUST buy the most expensive panels because they are designed to deal with the shade.

I'd love to ask him to explain why the most expensive panel deals with shade better than a cheaper panel which has more bypass diodes.

In other news, great experiment.

I do think that the trees should be cut back so that you receive zero shade on the roof at all times if you want this to be an accurate experiment.

I'm looking forward to seeing how they get on. My prediction is that the Sanyo panels will come more into their own towards the summer and produce more than the cheaper panels over the year - however, not enough to justify their extra cost.

 

[SolarCity]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

Suntech monocrystaline panels are outperforming Sanyo Hits in low light conditions by 10-15%, but underperfoming significantly in bright conditions (40%).

Interesting stuff.

How long has the experiment been going on?

The reason I ask is that low light can also mean that the panels are cooler. In the winter this will put the Sanyo panels at a disadvantage as they work better in warm conditions. I would expect the Sanyo panels to perform better in low light conditions AND bright conditions when the summer rolls in.

Keep us informed of how it goes.

 

[Mark42]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

It looks like the Henji panels have an Vmp of around 50V per panel, vs around 36V for the Sanyo H series panels.

The voltage of the array relative to the inverters peak operating voltage can make a significant difference in the inverter efficiency - 2-3% sometimes, so for the experiment to be fair the panels should both have been at the same (or very similar) operating voltage.

You may be able to use the inverter's performance data to work out a correction factor to apply to remove the impact of this aspect of the design from the results.

Thanks Gavin, you are quite correct. I engineered out much of this potential error by wiring the HJs series-parallel and the Sanyo in straight series. An extract from my as-built spec (volt drop calcs) appears below.

It works out that the Vmp for the HJs is 466V, and the Sanyos 642V. So yes, greater cable losses for the HJ array, disadvantaging the HJs (although only really significant as max power is approached), and possibly different inverter efficiency at these two voltages.

You are right in that this should (at least to some extent) be allowed for in the final verdict. BUT it could also be argued that the voltages chosen by the manufacturers are whatever they are, with a corresponding impact on efficiency in a real world scenario, as this is.

This morning the HJs were running at 388V, and the Sanyos at 549V, which is within a few percent of the theoretical ratio.

Cheers, Mark



ARRAY 1 (HJ)
16No. 250W Hengji Solar HJM250M-3232 panels, wired in two series circuits of 8 panels each, paralleled.

Total current at max power, where panel Imp = 4.94A
4.94 x 2 x 1.25 = 12.35A
Total voltage at max power, where panel Vmp = 50.6V
50.6V x 8 x 1.15 = 466V

Total Isc where panel Isc = 5.35A
5.35 x 2 x 1.25 = 13.4A
Total Voc where panel Voc = 60.5V
60.5 x 8 x 1.15 = 560V

Note the de-rating factors of 25% and 15% are to allow for possibly over-spec panels.

Cable volt drop calculation for the 180m dc run on 10mm 4-core (4.7 mA/V/m):

Vd = 4.7 x 180 x 12.35 / 1000 v = 10.45V

10.45 / 466 x 100% = 2.24%



ARRAY 2 (Sanyo)
16No. 250W Sanyo HIT-H250-E1 panels, wired in a single series circuit of all16 panels.

Total current at max power, where panel Imp = 7.18A
7.18 x 1 x 1.25 = 9.0A
Total voltage at max power, where panel Vmp = 34.9V
34.9V x 16 x 1.15 = 642.2V

Total Isc where panel Isc = 7.74A
7.74 x 1 x 1.25 = 9.68A
Total Voc where panel Voc = 43.1V 4
3.1 x 16 x 1.15 = 793.0V

Cable volt drop calculation for the 180m dc run on 10mm 4-core (4.7 mA/V/m):

Vd = 4.7 x 180 x 9 / 1000 v = 7.614V

7.614 / 642.2 x 100% = 1.19%

 

[Mark42]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

… Could you provide links to the datasheets for the panels and inverter? …

Here you are:

See spec for 3800S at: Diehl Controls: S

View attachment HJ Solar Mono 250W Panel - HJM250M-32 - spec sheet.pdf

View attachment Sanyo 250W panel - Spec sheet.pdf

 

[danesol]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

Well what would compliment all this is LIVE feed data going to a website with compounded figures, accurate logs of the weather overhead, relative to spot values and/or a live feed webcam looking at what the panels more or less are facing, as annual mean figures are one thing but it would be also nice to see how both sets of panels react to different levels of light at different times of the day

 

[whinmoor]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

How about a live interview with a panel to find out how it is feeling being put under this much pressure to perform?

 

[Gavin A]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

BUT it could also be argued that the voltages chosen by the manufacturers are whatever they are, with a corresponding impact on efficiency in a real world scenario, as this is.

you could indeed argue that, but it'd be a flawed argument that'd be pretty easy to shoot down for reasons that really ought to be obvious.

 

[Vegelen]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

How about a live interview with a panel to find out how it is feeling being put under this much pressure to perform?

Will the panels get randomly drug tested to make sure no ones tempted to use performance enhancing drugs?

 

[series530]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

Irrespective of second order effects, I feel that the OP should be applauded for running the test. As has been stated many times on every PV forum, data is only useful under real world conditions and under the same conditions. Placing arrays as you have is about as good as you can sensibly get. I see no issue with shading. Most of us have some. It will be interesting to see how the two panel types behave given the fact that their diode arrangements and bypass zones are totally different. I would like to see some form of dappled shading retained across the whole array as this is far more real world.

 

[matt25]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

Awesome experiment, very well done. Great for mere mortals such as myself!

 

[danesol]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

Irrespective of second order effects, I feel that the OP should be applauded for running the test. As has been stated many times on every PV forum, data is only useful under real world conditions and under the same conditions. Placing arrays as you have is about as good as you can sensibly get. I see no issue with shading. Most of us have some. It will be interesting to see how the two panel types behave given the fact that their diode arrangements and bypass zones are totally different. I would like to see some form of dappled shading retained across the whole array as this is far more real world.

Indeed, I agree as in the olden days we had ppl like "WHICH" who use to do tests/comparisons of such nature..........

 

[PhilSouth]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

At face value, this appears to be a good experiment. If it was meant to be 100% scientific then it would be taking place in a lab! This is being done in the real world, in real life conditions so would be keen to see the results.
Part of the reason I have replied to this thread is so I can stay up to date with it but having tracked down the co-ordinates to somewhere around Tibenham, I am only about 6 miles away so the data would be very interesting from a local, personal point of view.

 

[Vegelen]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

I am currently monitoring 2 systems: Suntech v Sanyo Hits

Suntech monocrystaline panels are outperforming Sanyo Hits in low light conditions by 10-15%, but underperfoming significantly in bright conditions (40%).

After a "Burn in Period" The Suntech 250W are now performing better in low light conditions and very close to the efficiency of the Sanyo HITS in bright light conditions.

Moral of this story? Sanyo HITS are far more expensive, but dont outperform as much as they need to, to justify their economic outlay.
The Sanyo Hit panels are currently outperforming the monocrystalline Suntechs by 4-5%. They cost a 40-55% premium.

 

[SolarCity]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

After a "Burn in Period" The Suntech 250W are now performing better in low light conditions and very close to the efficiency of the Sanyo HITS in bright light conditions.

Moral of this story? Sanyo HITS are far more expensive, but dont outperform as much as they need to, to justify their economic outlay.
The Sanyo Hit panels are currently outperforming the monocrystalline Suntechs by 4-5%. They cost a 40-55% premium.

To be totally honest, I am a fan of Suntech panels but this just isn't good science. The Suntech panels are fitted at a better pitch (30 degrees) than the Sanyo system (45 degrees) and we know very little else about the systems.

The data suggests that both systems are south facing and unshaded - now we all know that if they are going by SAP calculations then zero shading doesn't exactly mean just that. We don't know how the inverters are mounted, how far the cable run is or pretty much anything else about it.

 

[Vegelen]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

Thor v Uxello Solar:

Ask questions and enter the debate....

Help me explain why the latest Suntech monocrystallines should be performing so well relative to Sanyo 250 HITS on 2 similar systems 10km apart.

The Suntech solar array with transformerless inverter was earthed on the 28th March 2012.

Since that date the 2 systems relative performance has narrowed.

 

[morpheus75]

Great experiment would love to hear how its all going over the course of the year(s) to come.


Sent from my iPhone using Tapatalk

 

[SolarCity]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

How can you be sure that they are in equal conditions?

 

[Vegelen]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

How can you be sure that they are in equal conditions?

The only way equal conditions can be found is by installing side by side.

Do you know a millionaire locally that will fund such an experiment?

I'd be happy to see the results.

I know what we'd find, that the Sanyo 250 HIT's generate marginally more than the

latest Suntech's. The Suntech STP250S - 20/Wd monocrystaline panels have a

module efficiency of 15.2% versus 18% on the Sanyo HIT-H250-E1.

The Sanyo HIT 240's are 19% and the latest Sunpowers at approximately 20-21%.

All are very much more expensive.

Economically they wouldn't be worth investing in over 25 years, unless maximising

solar power generation for a fixed size of roof, where panel size affected the amount

of panels that could be installed in a limited space.

Anyone with a commercial interest in installing Sanyo Hits would be likely to

challenge these results, as they have economic interests to protect.

Unfortunately I dont.

I care to find the best quality panel, outputting the most energy over 25 years, In

typical conditions that prevail in North West England.

If I lived in Greece with greater average sunshine another panel may be my panel of choice.

Some PV panels perform better in low light than others etc.

Some perform better in high light conditions and greater temperatures etc.

Choosing the right solar panel for your environment, depends on where you live, the

typical weather conditions that surround you, your size of roof and a few additional

factors, IMHO.

 

[SolarCity]

Re: PV Panel War: Sanyo v. Hengji. The ultimate side-by-side long-term, real-world t

The only way equal conditions can be found is by installing side by side.

Do you know a millionaire locally that will fund such an experiment?

I'd be happy to see the results.

As would I.

All I am saying is that to compare these two systems is not very good science, particularly when you understand just how much impact orientation, pitch and shading can have on a system.

To take these two systems and then to go and make a conclusion based on the results is not going to very accurate.