My Panels Not performing as well as neighbour

[mike36]

Hi

I have a system fitted 18 months ago SMA 4000 inverter and 16 Sharp 250 panels. My neighbor has Sanyo panels - they are smaller but he gets more KW's than i do and we have identical roofs and face the same way

My question is can I change the existing panels for Sanyo - I was told this would invalidate my Feed In Tariff

Thanks for any help

 

[SolarCity]

How much more kWhs is your neighbour getting?

 

[mike36]

about 6 - 7 % more

 

[liquidity]

Interesting comparison. Any shading at all? Difference in roof pitch? Optitrac turned off?

 

[whinmoor]

Did his system cost 6 - 7% more than yours?

 

[Ian-LS]

I think Sharp had/has a high temperature coefficient of -0.47%/deg and Sanyo has -0.3%/ deg so that would explain the difference in performance. In peak sunlight the Sanyo panels would produce around 6% more kWh. Your neighbour will have forked out several thousand more to install the sanyo system so had paid have more efficient panels.

 

[Darkwood]

When was your neighbours fitted?
Do you clean your panels regular and does your neighbour?
Was this a verbal or did you see the results...... he might just be jealous because yours are bigger ..... just too many variables to go for the swap em option make sure you have your facts right and that your comparing two systems with the same set-up ....i.e. angle, direction, pitch any shadows etc etc

 

[mike36]

Hi thanks for the response - most of which is over my head - We have the same Barratt house on the same side of the street - will I lose FIt if I change panels?

 

[Ian-LS]

Yes you would lose your FIT if you changed your panels as a new MCS certificate would need to be produced meaning you'll be put on the currrent 15.44p/kWh. In addition nobody else would want to buy the Sharp panels you have as they cannot be used again for another Solar PV system if they also want to claim the feed in tariff as the equipment would be 2nd hand.

You'll have to stick with what you have I am afraid. I'm sure the fact you are getting the higher 43.3p/kWh Feed in Tariff rate will soften the blow somewhat

However if your system is performing below whats expected/predicted then there might be ways to improve this but if you are just disappointed that your neighbor has more efficient panels than you then you'll just have to be a jealous admirer

 

[liquidity]

Dunno about the FIT but 2nd hand panels have little value and you're almost certain never to recover the cost of buying and installing a 2nd set of panels.

 

[Vegelen]

Q/ I own a Lotus car. My neighbor has a Ferrari - his car accelerates faster than mine and does a couple more miles to the gallon.

My question is:
Can I, should I change my Lotus for a Ferrari?
Would it be worth it, given his car accelerates marginally faster than mine and does more miles to the gallon?

A/ Yes you should, you cant afford to loose face with your neighbour.

Put common sense on the back burner, empty your wallet, spend lots of cash and make sure you buy something far superior to his - to regain your rightful standing in the neighbourhood.

:auto:

 

[Earthstore]

This is just a suggestion, if you want to up your performance you may do better changing the inverter to maybe an SMA 3600TL, this may cost around £1000, but it would take a few calculations to see if it would be better suited.

Also to compare systems you need to compare the whole install, Where are the inverters mounted? How is it all wired up? What size is the AC cable? Where and how is it connected to the supply, Where are the Generation meters installed?
Are both inverters the same spec, Have the parameters been changed in the inverters? Are the panels wired in one string or two?

There is a lot more to a systems performance than just the panels, and normally, not always, but normally, any company that uses top end products like Sanyo's tend to have higher standards of work, and with PV any small thing (some listed above) can make a difference.

If you are that concerned it may be worth paying an expert to pop round and have a look at both systems to see if there is a way of improving your performance a little.

Out of curiosity, do you know what the price difference was between the two installs?

 

[Vegelen]

The cost of buying 16 Sanyo panels v 16 Sharp Panels 18 months ago, will far outweigh the 6-7% generation benefit your neighbour will receive.
He'll probably start to profit from his panel choice 18-20 years down the line.
At that point he'll most probably be dead or have moved.
If I was in your shoes, i'd be happy with your systems relative performance.

 

[Earthstore]

He'll probably start to profit from his panel choice 18-20 years down the line.
At that point he'll most probably be dead or have moved.

If that happens, pop round and swap them over while they are sorting the probate out, but don't tell anyone....

 

[Worcester]

And install an immersun (assuming you've got an immersion heater) and get 'free' hot water during the summer whilst he throws his away to the grid arty:, then revel in the fact that £ / £ your system is giving you a greater ROI

 

[Vegelen]

Install Solar Panel DC Optimisers, operating Mppt tracking per panel, to extract more energy from your panels.
These devices are most effective on systems with intermittent shading. :beatnik2:

 

[SRE]

I'm not sure if I've missed something but I don't understand what all the fuss is about. Sanyo panels are sold on the basis that they will generate around 10% more than "normal" poly or mono panels. If they are only producing around 6-7% more then I'd be jumping for joy at the fact that I hadn't paid out all that extra cash just to get 6-7% extra.

You'd be madder than a Mad Hatter at a Tea party to want to change over panels and pay the extra.

 

[SibertSolar]

Ditto that, about time someone said it....

 

[Vegelen]

:iagree:

 

[Worcester]

Soem of my panels are bluish and some of them are blackish, should I paint them all the same colour? :13:

 

[Gary K]

Soem of my panels are bluish and some of them are blackish, should I paint them all the same colour? :13:

Try white -they will be so much more efficient as they will reflect the heat and run cooler LOL

 

[Gavin A]

I'm not sure if I've missed something but I don't understand what all the fuss is about. Sanyo panels are sold on the basis that they will generate around 10% more than "normal" poly or mono panels. If they are only producing around 6-7% more then I'd be jumping for joy at the fact that I hadn't paid out all that extra cash just to get 6-7% extra.

You'd be madder than a Mad Hatter at a Tea party to want to change over panels and pay the extra.

who sells them on that basis?

We've always worked on around 5% performance advantage over the year in the UK from the better high temperature and low light performance, though actually I don't think there's any difference in the low light performance between them and the best poly panels, or even the better mono panels like the Yingli Panda, or others using the same cell type.

 

[Vegelen]

In exceptionally overcast / rainy years, they can underperform inexpensive, good quality monocrystaline panels, due to their unimpressive performance in low light conditions
(like happened in 2012 in North West England).
In sunnier parts of the UK i.e Cambridge, Cornwall etc outperformance of 5-10% is possible annually, due to their excellent performance in bright sunlight.
In Northwest England, Sanyo 250 HITS typically outperform Suntech STP250S-Wd+ by 5-7% in bright sunny weather / clear skies, but persistently underperform in low light.
How much bright sunny weather v overcast weather dictates the level of outperformance / underperformance between a high quality, expensive panel and a far cheaper, good quality panel.

 

[Berneray]

Have a look at your original SAP2009 projection which you would have received from your installer at that time........

Is your system performing in line with that projection. If so then be happy with it as that is one of the criteria you based your buying decision on.

 

[zeljuga]

Citat:

Originally Posted by Vegelen He'll probably start to profit from his panel choice 18-20 years down the line.
At that point he'll most probably be dead or have moved.



'If that happens, pop round and swap them over while they are sorting the probate out, but don't tell anyone....'

Naah , Just swap DC cables overnight. Easy one.

 

[Gavin A]

In exceptionally overcast / rainy years, they can underperform inexpensive, good quality monocrystaline panels, due to their unimpressive performance in low light conditions.

I don't think that's right.

It's not the low light performance that's having that affect - the low light performance is better than the vast majority of mono panels at 25 deg panel temps.

What I'd expect s happening there is that in colder weather the high temperature advantage of the panels works in reverse, so the mono panels improve their output at 0.45%/deg C below 25 deg C vs 0.3%/deg C for the Panasonic HIT.

So the effect my well be as you describe, but let's get the cause of it assigned properly.

I reckon it'd be interesting to actually monitor the panel temperatures through the year to see what proportion of the generation is produced above and below 25 degrees panel temperatures in the UK. Unfortunately this is a bit hard to achieve on a working system as any probe attached to the front of the panel would cause shading and output loss on the panel, and the rear of the panel is a lot cooler than the front in full sunlight. I might have a go at this though as we've got a solar water heating monitoring system running on our house which has spare sensor channels I could use.

 

[Vegelen]

A few points of curiosity.

How do solar panel temperatures fluctuate in different parts of the UK, at different locations and latitudes?
How does temperature affect solar panels and their ability to generate, with differing temperature coefficients?
Is a solar panels power temperature coefficient constant or does it change with temperature?
How does wind and rain affect panel generation ability?
How does temperature affect solar inverter longevity and its ability to generate?

 

[SolarCity]

Vegelen's data on Sanya vs other panels doesn't correlate with data that we have. Sanyo panels seem to outperform nearly all other panels we have installed in ALL conditions.

I'd be interested to see some data from other installers.

Linuo panels appear to be doing really well but from what I can make out, they don't necessarily do any better in colder temps than Sanyo.

 

[zeljuga]

I have small test set up Sanyo 250 side by side with Schoot thin film over the last year. On dull cloudy days thin film Schoot panels regularly equals or slightly outperform Sanyo.In wp per wp comperesment . Elevation 35`: S SW.

 

[Gavin A]

I have small test set up Sanyo 250 side by side with Schoot thin film over the last year. On dull cloudy days thin film Schoot panels regularly equals or slightly outperform Sanyo.In wp per wp comperesment . Elevation 35`: S SW.

to be expected, as that's what thin film is designed to do, and the reason Sanyo / Panasonic are good in low light conditions is that they have 2 x thin film layers.

 

[Vegelen]

Living close to the Peak District we get lots of overcast weather, wind and rain helping keep our panels cool.
The weather here is very different to that found in the Midlands / Greater Manchester.
I wonder what people further north are observing?
Do Sanyo HITS outperform in Scotland in lower light / temperature v other panels?

 

[Earthstore]

What has happened to he op?

 

[Mainman]

Q/ I own a Lotus car. My neighbor has a Ferrari - his car accelerates faster than mine and does a couple more miles to the gallon.

My question is:
Can I, should I change my Lotus for a Ferrari?
Would it be worth it, given his car accelerates marginally faster than mine and does more miles to the gallon?

A/ Yes you should, you cant afford to loose face with your neighbour.

Put common sense on the back burner, empty your wallet, spend lots of cash and make sure you buy something far superior to his - to regain your rightful standing in the neighbourhood.

:auto:

Why break you neck to try and get up to their level - bring them down to yours and torch his car / throw stones at his panels

 

[Earthstore]

Why break you neck to try and get up to their level - bring them down to yours and torch his car / throw stones at his panels

Or do what I have done on a holiday at a caravan park, throw bread on the roof next door at night, made our holiday more fun, and what goes in must come out, bird do do drops performance even on Sanyo's..

 

[Vegelen]

What has happened to he op?

Swapping his systems DC cables with his neighbours in the dead of night... :46:

 

[ian.settle1]

What has happened to he op?

Probabily got the hump, he sounds a bit of a minge bag

 

[mdovey]

What has happened to he op?

Well, the first few posts answered his question (viz sanyo will have a better output on hot sunny days, but also come as a cost which hits ROI in the first 10-20 years; making any changes will be costly and reduce the FIT). Recent posts have been mocking the OP, so it isn't surprising he's taken his answer and gone away.

 

[Worcester]

There have been some sensible suggestions
1) He can't change his panels without redcing his FiT so a sensible ROI on the total investment (changing panels) will never be achieved
2) He should check his current ROI and so long as he paid a sensible price and wasn't taken for a ride in the first place - he will generally have a better short term ROI than his neighbour.

- the only things that he can do without affecting his feed in tarrif relate to optimisation:
2) If going single inverter has he got the best matched one to his panels / string configuration / location / orientation / elevation
3) he MAY be able to improve output using panel based optimisation e.g. Solar Edge / Tigo - he can do both of those without affecting his FiT payments however it will require scaffolding and all the panels to come off the roof and be resinstalled.

The bottom line is he made his decision with the best information available to him at the time - based on the time and effort he put into the research he did himself at the time.

SO get on with it

It is a classic case of the grass is always greener / buyers remorse - it may not be a term you have heard of before, i can GUARANTEE that YOU have felt it at some time though!


Buyer's remorse - Wikipedia, the free encyclopedia
Home Buying - How to Avoid Home Buyer's Remorse
Avoid Buyer's Remorse - AskMen

 

[liquidity]

I reckon it'd be interesting to actually monitor the panel temperatures through the year to see what proportion of the generation is produced above and below 25 degrees panel temperatures in the UK. Unfortunately this is a bit hard to achieve on a working system as any probe attached to the front of the panel would cause shading and output loss on the panel, and the rear of the panel is a lot cooler than the front in full sunlight. I might have a go at this though as we've got a solar water heating monitoring system running on our house which has spare sensor channels I could use.

I had a play last summer with a temperature probe underneath the panel and an IR thermometer from above - there was no discernible difference. Not much of a surprise really; the panels are quite thin.

 

[SpitfireW'sale]

Hi

I have a system fitted 18 months ago SMA 4000 inverter and 16 Sharp 250 panels. My neighbor has Sanyo panels - they are smaller but he gets more KW's than i do and we have identical roofs and face the same way

My question is can I change the existing panels for Sanyo - I was told this would invalidate my Feed In Tariff

Thanks for any help

The output of the system depends on the efficiency of the inverter, panel, sizing factor and installation. As long as everything else is the same but efficiency of the panel, it makes sense that the two systems have different output.

Sharp module has 15.2% efficiency.
Sanyo module has 18% efficiency and therefore higher price.

Bear in mind that your neighbour's capital cost was higher and the payback period will be slightly longer.