Sanyo Hit-N system instaleed, results

[Aquinas_Quark]

Hello all, hope this is of some interest. I could find very few results of actual installed systems on the forums, so this may be of some help.
Just had (Thursday 13th Oct) a 15 x (could not fit 16, not enough space) Sanyo HIT-N240SE10 panels + Fronius IG-TL 3.6 inverter.
Location, sunny(?) Poole, Dorset, very nearly South facing, 40 degrees pitch. 12 panels on main roof, 3 on a gable end (same orientation). Slight morning shading from neighbour's tree, slight evening from gable onto main roof.
First impressions - the inverter is very quiet, slight buzz above 1.5kW output, fan cuts in at about 1.8kW; perhaps equal to someone talking quietly.
The inverter goes down to 100W or less output before quitting!
The output fluctuates wildly as clouds go over - often 300W to 2kW within a minute - makes planning use of the generated power a challenge!
640V DC off the panels even at a pathetic 220W AC output from inverter.
Peak output observed so far 3.3 kW (Saturday).
Cloudy Friday, 7 kWh output; sunny periods Saturday, 13 kWh ; cloudy Sunday, 7kWh.
An impotant tip: I made a scale cardboard plan of my roof and cut card rectangles for panels. By putting them in different arrangements I managed to get FOUR more panels on than my installer's software was saying (!!). Software output is only as good as the input one puts in.....
Any questions feel free to ask.

 

[TrickyDicky101]

Hi

I am due to have my 15 Sanyo HIT N235s installed this week not a million miles from you (Eastleigh, Hampshire) on Southerly facing roof (some potential limited shading issues from trees) coupled with a Fronius IG TL 3.0. Will be interesting to compare our results.

Richard

 

[Aquinas_Quark]

Hi Richard, why not 240W as they are the same size? Alan

 

[TrickyDicky101]

Hi Alan

My installer seemed to think the N235s were a better match to my inverter than the 240s with the next size up inverter (I have read that the inverter's peak output should be less than your array's peak for most efficient usage). I don't think it's going to be a big difference though (our systems are virtually identical in terms of array size, yours being 0.075kWP bigger than mine).

 

[Aquinas_Quark]

I make 15 x 235 = 3.525 kW peak; I understand the inverter runs better slightly overrated, but a 3.0 inverter on a 3.525 system? I would do some research on that (we all hope for slightly MORE kW when it's blazing sunshine - I believe Sanyo panels may give +10% over rated value ; but of course when hot they produce less...)
Cheers
Alan

 

[Aquinas_Quark]

PS
Fronius site says

DC max 3130 W, voltage range 350-700V DC, max AC 3kW for the IG TL 3.0.... PPS my system £12,400; can I ask what your quote is? Cheers Alan

 

[TrickyDicky101]

I did question the size originally, but was assured that Fronius's own software says it is the best match for the N235s. Your quote is a shade under £500 less than mine - did you get a 20yr warrany with the inverter? Very good quote if so

 

[Aquinas_Quark]

Yes 20 yr warranty; I had about 10-12 quotes, the one I went with seemed the most informed, and also was cheapest in £/kWp.
Good luck and let me know your output when up & running!
Cheers
Alan

 

[Scott H]

cheapest quote doesn't mean its the best installation ... just the cheapest!

Speak to the installers about how they will complete the installation, i.e. fixings?
Do they offer a maintenance service and if so what are the costs?
Whats covered in their warranty?

Solar PV isn't a cheap throwaway product, you should hopefully only ever have one installation so it needs to be right on day 1.

just my 2p worth

Scott

 

[Aquinas_Quark]

Hi Scott, I thought my first post was crystal clear; I have had the system installed. 20 years inverter, 10 years warranty on panels, plus 20 year panel output guarantee as normal, 10 year iwa.biz warranty on workmanship (whatever that means). The installer was the most knowledgeable (in fact it was the owner of the company who came to quote) and so far all seems well. Cheers Alan

 

[Gary K]

Have had my Sanyo system running for 2 weeks tomorrow consisting of 16 x N240SE10 panels with a sunnyboy inverter and so far it has made 116kwh. Orientation SSW 41 degree pitch with no shading. Best day so far was Saturday with the sunnybeam showing a lovely smooth curve and a production of 18.6kwh

 

[SRE]

Have had my Sanyo system running for 2 weeks tomorrow consisting of 16 x N240SE10 panels with a sunnyboy inverter and so far it has made 116kwh. Orientation SSW 41 degree pitch with no shading. Best day so far was Saturday with the sunnybeam showing a lovely smooth curve and a production of 18.6kwh

Interesting seeing what your best reading was, where are you located? I'm on the England / Scotland border with a 3.96 Sharp array 51 degrees East so not ideal, but we generated 16kwh on our best day last week and it was by no means a sunny day all day. In fact I can't remember a day in the last fortnight that hasn't had wind and cloud .......

 

[Gary K]

I am just on the outskirts of Norwich in sunny(?) Norfolk

 

[MorganPVI]

Has anyone actual read the terms and conditions of a 10yr insurance backed warranty? Read em - you'll be surprised.

 

[powervan]

Just installed 16 sanyo hit 240se10 with sunnyboy 3800 and sunnybeam for £11800 plus 5% (its a nice looking system)u wont be dissapointed!

 

[wildmanmk2]

hmmm all this makes very good reading , but at the same time ,, makes you more confused about what system your looking at .. I am thinking of a system made up of 16 sanyo hit 250h serious and they are telling me a power 1 3.6 aurora invert with 10 year warr , for £12300 inc vat .. but not sure about the invert i think its too small for the system seeing as the sanyo peak power could be %10 higher which means it being around 4.5kw which i think is too high for the invertor , would be nice to hear what you guys think of the invertor /panel match ... thanks

 

[SolarCity]

£12.3k including VAT? Absolutely ridiculous price.

As for the inverter, I would say it is a good choice. Your system will occasionally outperform the 4kWp rating but it will be uncommon. Upgrading the size of the inverter would be uneconomical.

 

[wildmanmk2]

hi again , many thanks for your reply biggssolar ,, i have to say that my roof is perfect south and 30 degree pitch and in notts area so should give some good results ,, i think its a great price ,, i did work hard on bringing him down , just going to check one of their installs next week to check the work .. So i take it that even thou you fit a 4kw system , it never really gives you that back only on a few great days ,,

 

[SolarCity]

It will produce 4kW but the increase over, for example, 3.68kW is not great. The extra 320 watts occasionally is just not worth it from a financial point of view.

 

[wildmanmk2]

oh one other thing if you all dont mind , this company is saying they wont fit the invertor in the attic space due to high fluctations of temp in there , that could affect the invertor , but i have checked the spec on the aurora , and it says it will work in temp -25 to +60 i can never see my loft getting anywhere near that heat in the uk .. does anybody else have views on this matter .. thanks in advance .

 

[SolarCity]

I'd strongly agree with the installer on this one. You'd be surprised at how hot your loft gets in midsummer - especially with the new inverter throwing more heat out. The efficiency, and the life, of the system will reduce as the temperature rises.

 

[TrickyDicky101]

Hi Alan

My system was installed Thurs/Fri last week. Since then, I have observed a maximum peak output of 2.8kW on Saturday. Total generation to date has been c. 38kWh. Like you, the impact of cloud has been tremendous (IMO anyway): today with a clear sky I was getting 2.0ish kW at 11am, then some cloud came over at 1pm or so (and by no means was it dark or dingy at this stage) and peak dropped to c.400kW. I do wonder how much will be generated on a cloudy and rainy day - I suspect it won't be very much at all.

Best regards

Richard

 

[kate.harrison1]

Hi Richard,
Many thanks for your pm from the other forum. As you can see, I have managed to finf this one and, as you say, has some interesting posts. I am still somewhat baffled at the apparent discrepancy of peoples outputs. As I said, mine, commisioned late morning on 20th and consisting of 16 Sanyo 240HIT ( 8 west facing and 8 east facing) plus SMA400TL has now generated a total of 34.24 at close of play today> Averaged out, that is about 5.7kw per day. If the weather was cloudy, ok, but it has been pretty sunny the whole time since installation so I am, frankly disappointed. I was advised that the south facing roof was only big enough to accommodate about 6 panels bu I am beginning to wonder whether we have made a mistake and should have just had fewer panels on the directly south facing roof. I was led to understand that inverters need a certain total power output to operate efficiently and that 5 or 6 panels would not have worked well.
I can only assume that the low figures are a combination of the low sun not shining directly onto the panels and the shorter trajectory of the sun meaning that it seems to rise and set further to the south than it does say during the spring and summer.
Unless there is some fault with my system, I suppose I have to just wait and watch what happens in the spring/summer when the sun passes right overhead and SHOULD enable something close to peak output. All models I looked at sugested about 15% lower output totals for e/w than s but I seem to be getting much lass than that. Also how does the poster earlier in this thread manage to get what she does from an EAST facing array of the same size on the Scottish borders??!! Do you reckon my inverter is not well matched?

 

[kate.harrison1]

Have had my Sanyo system running for 2 weeks tomorrow consisting of 16 x N240SE10 panels with a sunnyboy inverter and so far it has made 116kwh. Orientation SSW 41 degree pitch with no shading. Best day so far was Saturday with the sunnybeam showing a lovely smooth curve and a production of 18.6kwh

Gary,
Do you mind me asking you if your output has significantly dropped this week?

 

[Gary K]

Output is dropping as the sun follows a lower path. On Saturday the system maxed out at 2.96kw between the slight hazy cloud where as in the first couple of days of being turned on it was reading 3.17kw briefly.
the last few days have made-
24th - 11.89
23rd- 12.420
22nd- 15.86
21st- 11.188
20th- 16.686
19th- 14.152
18th- 15.185

toal in 21 days is 211.66
but the weather has been good

I have registered on PVoutput as Norwich Power if you like to compare.

 

[TrickyDicky101]

I'm envious of those generation figures Gary! It will be interesting to see what happens to them when the cloudy & rainy days hit us.

Kate, I suspect neither of us are going to be blown away by our generation figures until Spring/Summer next year (love to be proved wrong, however).

 

[series530]

Hi Richard,
Many thanks for your pm from the other forum. As you can see, I have managed to finf this one and, as you say, has some interesting posts. I am still somewhat baffled at the apparent discrepancy of peoples outputs. As I said, mine, commisioned late morning on 20th and consisting of 16 Sanyo 240HIT ( 8 west facing and 8 east facing) plus SMA400TL has now generated a total of 34.24 at close of play today> Averaged out, that is about 5.7kw per day. If the weather was cloudy, ok, but it has been pretty sunny the whole time since installation so I am, frankly disappointed. I was advised that the south facing roof was only big enough to accommodate about 6 panels bu I am beginning to wonder whether we have made a mistake and should have just had fewer panels on the directly south facing roof. I was led to understand that inverters need a certain total power output to operate efficiently and that 5 or 6 panels would not have worked well.
I can only assume that the low figures are a combination of the low sun not shining directly onto the panels and the shorter trajectory of the sun meaning that it seems to rise and set further to the south than it does say during the spring and summer.
Unless there is some fault with my system, I suppose I have to just wait and watch what happens in the spring/summer when the sun passes right overhead and SHOULD enable something close to peak output. All models I looked at sugested about 15% lower output totals for e/w than s but I seem to be getting much lass than that. Also how does the poster earlier in this thread manage to get what she does from an EAST facing array of the same size on the Scottish borders??!! Do you reckon my inverter is not well matched?

Kate,

just as a quick sanity check: do you know if the arrays on each of the roofs are on different strings from the inverter? The 4000TL has two strings (AFAIK) and each has an individual MPPT tracker. If one roof was suffering from low light it would not affect the other and you would maintain a reasonable overall harvest. If, for some reason, it was wired such that the two strings were distributed across each roof I could imagine that this may cause the lower energy.

The other consideration is the amount, if any, of shading. While there may not be any hard shading due to telegraph poles or dormers, do you get any diffused shading as a result of distant trees or trees with an open structure? Hard shading is bad but diffused shading, as I think I am conclusing through reading posts on here and on other forums, can sometimes have an even worse effect.

 

[Gary K]

I'm envious of those generation figures Gary! It will be interesting to see what happens to them when the cloudy & rainy days hit us.

Back down with a bump today . Started with cloud and light rain and gradually got brighter during day
total output 2.7kwh.
Told you the weather had been good in the last week!!!

 

[TrickyDicky101]

It's somewhat worrying the feelings of elation I get when the sun breaks cloud cover and my peak hits 2.5kW (in the last day anyway) followed by the emotional doldrums as the cloud and rain strike reducing peak to 193kW.

I'm pretty sure I'll get bored of this soon enough...

 

[zeljuga]

Output is dropping as the sun follows a lower path. On Saturday the system maxed out at 2.96kw between the slight hazy cloud where as in the first couple of days of being turned on it was reading 3.17kw briefly.
the last few days have made-
24th - 11.89
23rd- 12.420
22nd- 15.86
21st- 11.188
20th- 16.686
19th- 14.152
18th- 15.185

Average above: 13.9115714 kw /day
Multiply bay 365 days = 5077.72357 kw/year
Weary optimistic for 4 kwp system (October average output month for year)

However 211.66 kw for 21day , average :10.0790476 kw/day
Multiply bay 365 days = 3678.85238 kw/Year
Realistic output for 4kwp system . But optimistic for 3.84 kwp system

 

[kate.harrison1]

Kate,

just as a quick sanity check: do you know if the arrays on each of the roofs are on different strings from the inverter? The 4000TL has two strings (AFAIK) and each has an individual MPPT tracker. If one roof was suffering from low light it would not affect the other and you would maintain a reasonable overall harvest. If, for some reason, it was wired such that the two strings were distributed across each roof I could imagine that this may cause the lower energy.

The other consideration is the amount, if any, of shading. While there may not be any hard shading due to telegraph poles or dormers, do you get any diffused shading as a result of distant trees or trees with an open structure? Hard shading is bad but diffused shading, as I think I am conclusing through reading posts on here and on other forums, can sometimes have an even worse effect.

Ian, Thanks for your response to my query. Yes< is am pretty sure that it has been set up as two strings. There are separate DC isolator boxes beside the inverter clearly marked 'east' and 'west' and , when you tap the screen to light up the display,it flashes voltag/amps with a visual for 2 sides of panels. I'm sure you know what I am talking about!
As far as shding is concerned, there is none but on both sides, the sun is getting so low now that it sort of shines a glancing blow if that makes sense which is why, right now, I am regretting not overruling all advice(from 4 firms) and insisting on a string of 6 (all that would fit on hip roof`) on south facing roof, with its own inverter, plus a further whack of however many ~I could grt on either east or west, again, with a searate inverter. I suspect that the east might surpass the west.

As I said to Richard, you can only work with what you have got and perhaps come spring, when the sun is over the ridge again, my system will clock in early, fly on both sides in the middle part of the day, and clock off late: that was what I was told by all. In the meantime, it seems I will have to just put up with low production although when compared to outputs from Gary for the same dates in Norwich, there seems to be more than a 15% loss for being e/w. I will try to get figures from Sunny Explorer and post them for comparison.
Also, slightly concerning , on Saturday(22nd Oct) probably the sunniest in the last few days, we were away in Reading for the day and when we got back and I looked at the SBeam, it showed a weird drop out for a couple of hours. I queried it with my installer who has promised that the electrician will come and see me as soon as he can but having read the thread about compatibility issues with Sanyo/SMA, I wonder whether this may be happening too. On one of the other days, it also showed a sudden weird spike over the max capacity of our system and likely impossible especially at this time of year. I will try to get screen shots or photos but the technology may just beat me.
Probably not worth worrying too much at this stage. Will have to let them take down scaffold and live with it for a few months, see what happens come spring and summer. If it still seems to be underperforming, I am fairly confident that my installer will address the issues.

 

[kate.harrison1]

I'm envious of those generation figures Gary! It will be interesting to see what happens to them when the cloudy & rainy days hit us.

Kate, I suspect neither of us are going to be blown away by our generation figures until Spring/Summer next year (love to be proved wrong, however).

I think you might be right and we have to be patient and wait and see but I will be keeping a close eye (see my long post response to Ian)>
The next few days look like being pretty s*** so, I dont expect much more that 1 or 2 kw. I agree, it is pretty sad, watching the Sunny Beam all the time and being totally preoccupied but, we have all invested a great deal of hard-earned cash and want to feel we have done the best we can.

 

[series530]

Kate,

If my system was live I would be very happy to share data with you. Much to my annoyance, Enecsys still haven't supplied the inverters so I cannot. Our roof is SSW and we have some shading at various parts of the day (hence micro inversion). I'm looking forward to the possibility of monitoring each panel separately and being able to visually correlate sun. cloud and shade with energy harvest... well, that's the theory anyway. I remember looking at a few sample Enecsys live systems on the web while I was considering a purchase and it was very interesting to note that, on a single array, there could be a pretty wide variation of instantaneous panel harvest and that this variation fluctuated pretty wildly each and every time the data was updated. This was not consistent with shade because shade would have been fairly constant. In my mind it had to be clouds moving over the array. Unfortunately, being web based, my point of monitoring wasn't close to the installations so I could not not correlate yield with what was physically happening.
With string based arrays, as I understand it, the MPPT tracker will try to tune to the overall array capability and this capability will err toward the harvest of the least performing panel in that string (unless the bypass diodes kick in). On a cloudy day and with low light, the system performance will tend to follow this rule. As a consequence, your harvest will be a sum of the performance of each of your two strings and each string will tend toward the lowest performing panel. If you are east west, the potential harvest will be that bit lower and your harvest will be held back because of it. I suspect that, come the spring, when the light levels are higher, the overall harvest per panel will be much higher and the effects of things like cloud cover will be mitigated by the bypass diodes coming into operation when clouds pass over parts of the panels. With bypass diodes in circuit, although the tracker will still perform in the same way, the bypass diodes will temporarily switch out sections of panels that are cloudy and thus keep the operating point of the whole string at a higher yield.


I think you will need to grin and bear it for a bit and see how things go. East west will never be as good as due south but it should be decent enough output on a sunny day.

 

[SolarCity]

Also, slightly concerning , on Saturday(22nd Oct) probably the sunniest in the last few days, we were away in Reading for the day and when we got back and I looked at the SBeam, it showed a weird drop out for a couple of hours. I queried it with my installer who has promised that the electrician will come and see me as soon as he can but having read the thread about compatibility issues with Sanyo/SMA, I wonder whether this may be happening too. On one of the other days, it also showed a sudden weird spike over the max capacity of our system and likely impossible especially at this time of year. I will try to get screen shots or photos but the technology may just beat me. .

Hi Kate,

This sounds like it may be a grid voltage issue. Ask your electrician to check to make sure the voltage isn't too high. The voltages in homes tends to peak at around midday for a few reasons so it would be a good idea for your electrician to come and see you at that time. If the voltage is going beyond 253v then you can speak to your DNO and ask them to reduce the voltage. 253v is the maximum voltage that DNO's are permitted to distribute at.

 

[JohnBoyZ]

Hi Kate,

This sounds like it may be a grid voltage issue. Ask your electrician to check to make sure the voltage isn't too high. The voltages in homes tends to peak at around midday for a few reasons so it would be a good idea for your electrician to come and see you at that time. If the voltage is going beyond 253v then you can speak to your DNO and ask them to reduce the voltage. 253v is the maximum voltage that DNO's are permitted to distribute at.

I agree with you biggs but also get the electrician to check the grid settings on the inverter.
It has been known for an installer to assume the inverter is set to G83/1 but some 4000TL's are configured with G59/2 as factory default.
G59/2 has a two stage over voltage, (Stage 1 = 253v, stage 2=264.5v) whereas G83/1 has just the one over voltage limit at 264v. So G83/1 is more forgiving but of course it depends what the installer has agreed with the DNO. I'm guessing its G83/1 but if it the grid connection is agreed at G59/2 then the installer might get permission from the DNO to increase the stage 1 limits rather than the DNO reducing the voltage.

 

[SolarCity]

This is true but I'd argue that if the voltage is getting too high then you are going to want to get it lowered anyway. Voltages above 253v are not good idea. Electronic equipment will have shorter life and you will use more energy.

 

[JohnBoyZ]

This is true but I'd argue that if the voltage is getting too high then you are going to want to get it lowered anyway. Voltages above 253v are not good idea. Electronic equipment will have shorter life and you will use more energy.

Here here, couldn't agree more.

"Could always install a VPhase"

Who said that!l

Cheers
John

 

[Aquinas_Quark]

Hi Alan

My system was installed Thurs/Fri last week. Since then, I have observed a maximum peak output of 2.8kW on Saturday. Total generation to date has been c. 38kWh. Like you, the impact of cloud has been tremendous (IMO anyway): today with a clear sky I was getting 2.0ish kW at 11am, then some cloud came over at 1pm or so (and by no means was it dark or dingy at this stage) and peak dropped to c.400kW. I do wonder how much will be generated on a cloudy and rainy day - I suspect it won't be very much at all.

Best regards

Richard

Hi Richard (and greetings to all; I started this thread and see it has turned into a mini-epic! great!), my results:
15 x Sanyo Hit-N240SE 10 panels, Fronius IG-TL 3.6 so 3.6kW peak, Poole, Dorset, very near south facing 40 degree pitch, slight morning shade from tree. First operating day 14 Oct, total to this evening (18 days) 137 kWh (average 7.6kWh per day),
Best day 28 Oct. 14 kWh, worst 27th not even 1 kWh (!). I did see the output peak momentarily at just OVER 3.6 one day!!
Amazing how variable the output is - I know our eyes adjust to compensate for dim light but even so, output can be near 3kW one moment and down to 600W in a few seconds, so the real brightness is easily varying 10:1 - or more.
We are in during the day so have been running up and down stairs switching immersion heater/leccy radiators and blowers on and off, chasing the clouds across the sky - the exercise alone is warming the house!
I am trying to get a site transformer 240 to 110V to run the immersion heater (so 1/4 power, about 700W) and thinking about a storage heater to maybe charge over 2 days if it can be insulated; I wonder about power control whether a triac firing into a heavy load would give the inverter problems; would prefer to relay-switch a tapped transformer perhaps (with a delay so it's not on/off/on/off continually of course). I must ask the good doctor Fronius if his inverter can handle a chopped load waveform or not.
PS if your system gives you 400kW when cloudy I'll give you 50 grand for it....
Cheers
Alan

 

[Aquinas_Quark]

Output is dropping as the sun follows a lower path. On Saturday the system maxed out at 2.96kw between the slight hazy cloud where as in the first couple of days of being turned on it was reading 3.17kw briefly.
the last few days have made-
24th - 11.89
23rd- 12.420
22nd- 15.86
21st- 11.188
20th- 16.686
19th- 14.152
18th- 15.185

Average above: 13.9115714 kw /day
Multiply bay 365 days = 5077.72357 kw/year
Weary optimistic for 4 kwp system (October average output month for year)

However 211.66 kw for 21day , average :10.0790476 kw/day
Multiply bay 365 days = 3678.85238 kw/Year
Realistic output for 4kwp system . But optimistic for 3.84 kwp system

Excellent figures - where are you?
Cheers

 

[Gary K]

Excellent figures - where are you?
Cheers

They are my output figures and I am in Norwich.

 

[TrickyDicky101]

Hi Alan

You have better figures than me Do you have day-by-day breakdowns of generation available?

Richard

 

[Aquinas_Quark]

date (October)/kWh: 14/7 - 15/13 - 16/7 - 17/5 - 18/13 - 19/14 - 20/11 - 21/1 - 22/13 - 23/8 - 24/3 - 25/3 - 26/12 - 27/0 - 28/14 - 29/7 - 30/1 - 31/4 ==== total 136kWh (+1 kWh on day of installation 13/10, finished late)
Cheers
Alan

 

[Aquinas_Quark]

They are my output figures and I am in Norwich.

Hi Gary, I meant to ask zeljuga where he/she was. I already have a pin in the map for you at Norwich!
Alan

 

[dennis2011]

I have an East/West system as well - installed on October 8th. 10 x 190w Schott mono on each roof, 3800w total. Using Auror/PVI 3.6 inverter. Averaged so far 4.9kw per day so your 5.7kw average looks good to me. My PV Sol projection was 3048 KWh per annum - I expect yours to be 3200 plus. As you probably know - you only get about 85% of the yield from a dual East/West install compared with due South. That's why I went for a lower cost install to improve my pay back time.

 

[kate.harrison1]

I have an East/West system as well - installed on October 8th. 10 x 190w Schott mono on each roof, 3800w total. Using Auror/PVI 3.6 inverter. Averaged so far 4.9kw per day so your 5.7kw average looks good to me. My PV Sol projection was 3048 KWh per annum - I expect yours to be 3200 plus. As you probably know - you only get about 85% of the yield from a dual East/West install compared with due South. That's why I went for a lower cost install to improve my pay back time.

Hi Dennis,
I guess that was my post you were referring to? Figures have slipped a bit now cos we have had three really dark and/or wet days each of which produced just under 2kw each. Total is 63 for 11 days. I am quite surprised that there seems to be relatively little difference between dull days and bright days but put that down to the angle ie very low sun for e/w system. Actually, the scaffold has not come down yet for a number of reasons and I wonder whether the uprights are casting some shadow on bottom row of panels? Will see if it makes a diference when it comes down this week.

I know there is meant to be a lower prediction for e/w than s but I am hoping that ours will sort themselves out favourably in the spring/summer when we may get a longer production day plus pretty much the same as s during the middle part of the day?

 

[dennis2011]

Yes Kate, even small shadows affect system disproportionatley. My roof is only 33 degrees pitch, the shallower the better for a dual east/west. Did you know that even a flat roof gives 90% of the return of a due south roof? With east/west you get a longer more even production day without the big midday spike. Even in June with the sun directly overhead the sunlight is striking each panel at a glancing angle, hence one of the explanations for the 85% figure.
In the case of your installation you could have considered 6 panels on the south face plus 8 panels on the east face. You might have saved nearly £1000 on the install cost with very little reduction in annual output. The inverter still copes ok with 2 unequal strings. East is slightly better than West for 2 reasons. Firstly east roofs are usually colder than west roofs. Secondly due to the azimuth angle (tilt of the earth) changing through the seasons the sun rises closer to the South East on December 21st but closer to the North East on June 21st. June is one of the peak months for solar production.

 

[kate.harrison1]

Yes Kate, even small shadows affect system disproportionatley. My roof is only 33 degrees pitch, the shallower the better for a dual east/west. Did you know that even a flat roof gives 90% of the return of a due south roof? With east/west you get a longer more even production day without the big midday spike. Even in June with the sun directly overhead the sunlight is striking each panel at a glancing angle, hence one of the explanations for the 85% figure.
In the case of your installation you could have considered 6 panels on the south face plus 8 panels on the east face. You might have saved nearly £1000 on the install cost with very little reduction in annual output. The inverter still copes ok with 2 unequal strings. East is slightly better than West for 2 reasons. Firstly east roofs are usually colder than west roofs. Secondly due to the azimuth angle (tilt of the earth) changing through the seasons the sun rises closer to the South East on December 21st but closer to the North East on June 21st. June is one of the peak months for solar production.

Yes, hindsight is a wonderful thing! I was lead to believe by all four installers who quoted that the e/w was best for my property and that unequal strings would not work satisactorily. As a lay person, I found it hard to argue! The £1000 saving would presumably have been on the 2 extra panels as I would still have required two faces of scaffolding.

Do you really think 4000TL would work effectively with an e string of 8 panels in one track and a s string of 6 in the other? I suppose I could always argue that I was ill-advised and ask them th move them but I would have damaged roofing felt on one aspect and 2 spare panels, not to mention the fact that all installers, mine included will be going flat out in the foreseeable future.

Do you think a few scaffold poles might really affect output?

 

[series530]

Hi Kate,

the effects of shading can be very significant and, to my thinking, have even more effect as a percentage of output when the amount of energy available through sunlight is lower.

The following is a case in point. It references page 4 but you may want to read the whole thread so as to get the complete picture and some of the hypothesis presented.

http://www.electriciansforums.net/photovoltaic-solar-panels-green-energy-forum/41299-effects-shading-4.html

Once up and running (hopefully next week), I plan to investigate the effects of shading further as I will be able to analyse panel by panel. Unfortunately though, the week after, I'll be away during the week on business for quite some time, so the data may be a little slow in coming to the forum.

 

[dennis2011]

Yes, I estimated the saving as the cost + installation of 2 extra panels. Most twin input inverters should cope well with unequal string provided the necessary parameters are met. One of these is the start up voltage, in other words how much voltage is needed to get the inverter to start producing electricity. If this is too high for your panels than your inverter wiil only start up when your panels are producing peak voltage, or in extreme cases, on a badly designed system, the inverter would not start at all. Sanyo HIT panels produce about 30 volts per panel so your string of 8 panels will produce 240 volts and the string of 6 panels would produce 180 volts. I do not know the specs for the Sunny Boy 4000TL but for the Aurora PVI 3.6 it is factory set at 200 volts per input BUT it can be easily adjusted by the installer right down to 140 volts individually for each input. I would have suggested something like 140 volts for the 6 panel string and 180 volts for the 8 panel string.
I know it can be tedious, and it is not meant as a criticism of you, it's just the way I am, but I like to find out things myself as much as possible before I have any work done, so that I can clearly understand the pro and cons of various quotes.

 

[kate.harrison1]

Hi Dennis,
I too am fairly careful with my homework prior to decision making, but some of the nitty gritty electrical stuff was rather out of my comfort zone and, as I was consistently being told by all that it would be better to have the higher number of panels in equal strings on e/w than trying to squeeze a smaller number onto the south facing hip and some more on one of the other pitches. Perhaps I placed too much confidence in the expertise of the installers' advice but I can't really justify changing it all now! perhaps removing the scaffold poles will make a difference but I doubt anyone's system is doing more than a couple of Kw in this damp grey weather and I shall have to wait for spring and summer.

I have a growing list of questions to ask my installer, perhaps the one concerning me the most is about earthing. I have been reading threads on here and on other forums suggesting that the TL inverters must be earthed in a specific way. When I asked my electrician and installer, they said that no special earthing arrangements were required. I don't like to doubt their professionalism and have been given sheets of paper with the results of electrical tests etc so its not as if they haven't paid attention to it all. Of course the problem now is that they will all be manicly busy for the next few weeks and probably wont be too keen to come and answer my (perhaps unnecessary) questions!