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Advice on solar PV poor performance

(10 posts) (8 voices)

Started 10 years ago by rlwalters
Latest reply from Inspector

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rlwalters
Member

I had a 3kW solar PV system installed on my roof in Sydney more than a year ago. Without going through all the details, the company that supplied it (Nu Energy) did an audit some months after installation and found some kind of mistake in wiring. The technician said that the voltage was reading about half what it should be. For the first year of operation my energy output only averaged about 7.1kWhrs/day which is well under what I should expect (I believe to be more like 12 kWhr/day).

After numerous phone calls and a number of months later, I finally got them to come and fix the problem. Since then the energy output seems to have improved but I need to monitor for a longer period to see. Apart from looking at the readout on the inverter, my main means of monitoring output is via my bills which come quarterly.

What I would like advice on is:
What is the best way to verify the energy output of my system and whether it is producing what I should expect?
Would it be a good idea to get someone to independently check the system out? Who and how much might that cost?
What course of action should I take to resolve the issue if the system is still not performing up to scratch?
Is it appropriate to make a claim for the income that I have forgone (in relation to feed in tariff) due to the fault of the supplier? Do you know of anyone that has had success making such claims?

Hope someone can help,

Rick

Posted Monday 6 Feb 2012 @ 3:05:47 am from IP #
IAEA
Member

rlwalters states:
...... which is well under what I should expect (I believe to be more like 12kWhr/day).

http://www.yourhome.gov.au/technical/fs67.html#siting

This should give you a basis to start from.

IAEA

Posted Monday 6 Feb 2012 @ 3:18:21 am from IP #
Lance
Key Master

I would expect an average of around 12kWh a day in Sydney, maybe a bit more, but it depends on panel quality, inverter efficiency etc. If you are getting a peak output of 2.5kW or more on a sunny, cloud-free day, then it is performing correctly I would expect.

Posted Monday 6 Feb 2012 @ 3:19:35 am from IP #
Bushwalker
Member

rlwalters said:

What I would like advice on is:
What is the best way to verify the energy output of my system and whether it is producing what I should expect?
Would it be a good idea to get someone to independently check the system out? Who and how much might that cost?
What course of action should I take to resolve the issue if the system is still not performing up to scratch?
Is it appropriate to make a claim for the income that I have forgone (in relation to feed in tariff) due to the fault of the supplier? Do you know of anyone that has had success making such claims?

Hope someone can help,

Rick

I would suggest hooking your system up to pvoutput.org, or at least manually entering your daily outputs there. This way you would then be able to compare your system with other similar systems in the same region.

Depending on the make and model of your inverter, it may be possible to automate the logging of your system to pvoutput.

There is a thread on whirlpool forums devoted to pvoutput and which will supply help if you have difficulties. http://forums.whirlpool.net.au/forum-replies.cfm?t=1824518

Cheers,

BW

Posted Monday 6 Feb 2012 @ 7:33:45 am from IP #
photonthief
Member

Yes, a 3kW system in Sydney should give an annual average of around 12kWh/day, or a bit better if everything is optimum. However knowing the annual average does not help you much, as you can't affod to wait for a whole year to find out if the system is OK!! Daily output varies by about 2:1 for summer compared to winter, and also day-to-day.

I agree with Lance that on a CLOUDLESS sunny day in summer (ie, now) your inverter should be generating a peak AC power of around 2.5kW to 2.9kW at around midday. If so, then your basic system, panels, wiring and inverter are almost certainly OK. Under these conditions, what peak power are you observing?

On a cloudless sunny day in summer, you should generate around 17 kWh or even a bit more, but there are many factors which may result in less, which may not be due to a system fault as such. For example, do your panels face north? What is the pitch angle of your roof? Have your panels recently been cleaned? Lastly, and very importantly, to what extent are your panels shaded? More precisely, between what times of day are the panels COMPLETELY free of shade? Note that even partial shading will greatly and disproportionately reduce overall output.

Get back to us with answers to all those questions, and it probably be clear as whether you system is performing as it should.

Posted Monday 6 Feb 2012 @ 11:25:03 am from IP #
rlwalters
Member

Thanks everyone. To respond:
On 5/2/12 which was a good sunny day, I recall the total generation was about 17kWh and the peak was about 2.4kW (so maybe still a bit under what I should expect). Unfortunately I can't download from my inverter as its a pretty basic Aerosharp model. I might do some manual daily logging into PV Output as suggested for a comparison. Looking at Whirlpool, Aerosharp is a problem even though the manual I have says there is both RS485 and RF links available.

My system faces slightly north of north east, is tilted at about 30 degrees and has no shade, so it should function very effectively. I cleaned the panels before Christmas.

I eargerly await your further advice.

Posted Tuesday 7 Feb 2012 @ 4:33:51 am from IP #
dymonite69
Member

rlwalters said:
Thanks everyone. To respond:
On 5/2/12 which was a good sunny day, I recall the total generation was about 17kWh and the peak was about 2.4kW (so maybe still a bit under what I should expect).

A similar system with your aspect and location:

http://pvoutput.org/list.jsp?id=1040&sid=811

Generated 6kWh/kW on the 5/2/12

This would be 18 kWhr for a 3kW system so it seems your system is working OK now.

Posted Tuesday 7 Feb 2012 @ 8:53:31 am from IP #
rlwalters
Member

Thanks Dymonite69. That sounds positive. I'll keep an eye on things for a while and do some comparisons on PV Output.

Does anyone have any advice re the last part of my query:
Is it appropriate to make a claim for the income that I have forgone (in relation to feed in tariff) due to the fault of the supplier? Do you know of anyone that has had success making such claims?

I figure I have lost over $1000 in foregone revenue.

Posted Tuesday 7 Feb 2012 @ 11:09:26 am from IP #
Buzzman
Member

"My system faces slightly north of north east, is tilted at about 30 degrees and has no shade, so it should function very effectively..."

If that is magnetic north, then you are quite a way off optimum, which is about 6-8deg west of magnetic north (ie, 'true' north) according to the best info I can find, so if your system is getting the production levels it is, in a non-ideal aspect, I'd be happy!

Posted Friday 10 Feb 2012 @ 3:43:57 am from IP #
Inspector
Member

Re: claim from company for loss of income due to incorrect installation - You probably only have a few options, after calculating estimated loss:

1. contact NuEnergy in writing, requesting compensation (they would likely deny liability as it was the fault of the subcontracted installer)

2. contact the subcontracted installer directly (obtain details from CCEW form provided by installer) as per above. I don't like your chances even though he would likely be liable for failing to test the system correctly.

3. contact Fair Trading by phone to get advice. They might also suggest the above, or request you to lodge a formal complaint to them, for them to investigate.

Either way, I don't like your chances of success in receiving compensation. I've lost count of the systems I've seen with failed inverters, circuit breakers, incorrectly installed and in a few cases, not been working for over 12 months without the customer realising.

Posted Friday 10 Feb 2012 @ 11:21:15 am from IP #

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