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Solar trouble shooter


dnoble

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Can anyone recommend someone in the South West (Bristol) who could review and test my solar PV system and advise on installing storage batteries.

1)I have an allegedly 6Kwh  which has never generated more that 2.8Kw/h despite being well situated, shade free etc. Installers couldn’t really explain this and did some tests ultimately fobbing me off, this was over 2 years ago. I may just have unrealistic expectations.

2)There is also an issue that the fuse trips in windy/rainy conditions when the solar circuit is switched on. Never when it’s off so something’s amiss there. I installed the panels but not the inverter etc. 
3). I’ve got room to install another 12 panels all if this would be worthwhile, though wouldn’t bother if the existing ones could work at closer to predicted

4) would like advice on battery storage to be coordinated with the Sunamp, electric car Eddi/Harvi thing which should hoover up surplus PV in summer and also be charged up by the cheap Octopus plus 4 hours and then used to supply house the other 20 hours.

Hope that make sense? 

I’ve had a couple of leads but struggling to get anyone to visit!

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28 minutes ago, dnoble said:

1)I have an allegedly 6Kwh  which has never generated more that 2.8Kw/h despite being well situated, shade free etc

No you haven't. You have a system that has an installed capacity of 6 kW. If it has only generated 2.8 kWh in a day, the I suspect that something is seriously wrong.

What make inverter do you have?

What size is it?

Do the modules have optimisers on them?

 

There is always a possibility that some of the modules (the proper name for panels) are not connected up, or have become disconnected.

Let us get the existing PV working right first, then worry about a larger system and diverting power 

 

kW is power, kWh is energy.

The difference is important.

Edited by SteamyTea
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56 minutes ago, dnoble said:

Can anyone recommend someone in the South West (Bristol) who could review and test my solar PV system and advise on installing storage batteries.

1)I have an allegedly 6Kwh  which has never generated more that 2.8Kw/h despite being well situated, shade free etc. Installers couldn’t really explain this and did some tests ultimately fobbing me off, this was over 2 years ago. I may just have unrealistic expectations.

2)There is also an issue that the fuse trips in windy/rainy conditions when the solar circuit is switched on. Never when it’s off so something’s amiss there. I installed the panels but not the inverter etc. 
3). I’ve got room to install another 12 panels all if this would be worthwhile, though wouldn’t bother if the existing ones could work at closer to predicted

4) would like advice on battery storage to be coordinated with the Sunamp, electric car Eddi/Harvi thing which should hoover up surplus PV in summer and also be charged up by the cheap Octopus plus 4 hours and then used to supply house the other 20 hours.

Hope that make sense? 

I’ve had a couple of leads but struggling to get anyone to visit!

How many panels have you got and do you have their make and model and peak output rating?

 

Maybe you have a 6kW inverter not 6kW peak worth of panels. 

 

The "fuse" that trips, shall be a MCB, RCD or RCBO - the latter two trip if there is current leakage going somewhere it should not go and I think, given the conditions it trips under, that is your issue, caused maybe by water ingress. You need to confirm what trips. If it is an MCB then you may have a short somewhere that only faults when weather conditions impact it. This issue is probably AC side and an issue between your breaker and inverter or inverter itself. Unless you have a protective DC device?

 

I think photos would help us help you.

 

So lets work out what you have then that is that solved.

 

Batteries, are you regularly exporting a lot of energy? At 2.8kW peak I cannot imagine you are, therefore more panels probably make more sense first.

 

 

 

 

 

 

Edited by Carrerahill
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First off, how long ago was the system installed and was it a receipted job or cash? Exactly what was your involvement when you say "I installed the panels"? Did that include wiring or just mechanical? Basically, what was the installer contracted to do?

 

Given you seem to have several problems your easiest course of action may be to go back to the original installer if the circumstances allow, progressing it to the money claim service if necessary.

 

If you installed the panels do you know what wattage they were and how they were wired- series, parallel, single or multiple strings, optimsers etc?

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22 hours ago, Dillsue said:

First off, how long ago was the system installed and was it a receipted job or cash? Exactly what was your involvement when you say "I installed the panels"? Did that include wiring or just mechanical? Basically, what was the installer contracted to do?

 

Given you seem to have several problems your easiest course of action may be to go back to the original installer if the circumstances allow, progressing it to the money claim service if necessary.

 

If you installed the panels do you know what wattage they were and how they were wired- series, parallel, single or multiple strings, optimsers etc?

I mechanically installed the panels,

(Jinko Tigo 260W Smart Module with Gateway)

 

2 sets of 12 in series and connected up all the wires and ducted them through the roof. 

 

The folk who installed the inverter tested them and said they were fine, both sets generating. This was 2.5 years ago. 

They should potentially generate capacity of about 6KwH shouldn't they?  but in full sun have only ever produced 2.8 (confromed on the inverter, the eddi/harvi/zappi  thingy readout)

Excess goes into a 9kw sunamp and electric car.

It never fuses when the circuit with the solar panels/inverter on it is switched off.

I agree it sounds like a water ingress issue which is a bit dispiriting as I was very careful to avoid this when I installed it. 

I'm not an electrician or a solar installer and I think I need someone experience to get up and "have a look under the bonnett" 

The original installer did come back and did some calcs and sent me this graph which I think confirmed the output but didn't explain it (it may be my expectations/understandi are wrong).

either way the fusing problem persists so I could still do with someone to have a gander..

 

 

 

Hi Dan,

Following my site visit, I have now run my measurements through the standard MCS matrix to calculate your overall power generation.

Having measured the shading and applied the additional coefficient due to the proximity of the tree to the South East, the following graphic show a realistic generation that can be expected from your system under the current conditions. You should be able to compare the monthly projection against the accumulative figure on the Solar Generation Meter to reassure yourself that the system is working correctly.

Kind regards

image007.png

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1 hour ago, SteamyTea said:

Are these the Cloud based ones?

Were they setup and registered correctly?

They might be and I laboriously noted the numbers on the back of each one in anticipation of registering them on an app. They have "tigo optimisers" which were supplosed to correct probs with performance due to shading etc.  You can moniter this if you've registered/set it up, though I wasn't led to believe not doing this would adversly affect generation.

There was a complication in that they needed some kind of gismo in the loft which needed another electicity supply to run so I elected not to bother with any of that (I tend to avoid unnecessary complication/tech) and I was told it wouldn't make any differnce to performance.

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Have t read this in depth but the key word which jumped out at me was 'shading'. How badly does this affect your system?

 

That installer seems to think the numbers are correct when adjustments are made to account for shading?

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Do you have a generation electricity meter?  I would expect so, it is standard install procedure.  If it's all a bit DIY and you haven't (maybe it's not needed if not FIT or SEG, I don't know), I recommend getting a sparky to fit one.  Check it once a month or more, then you can compare with the installers expected yield graph you presented.  Maybe something you have already integrates the power, to energy in kWh?  The instantaneous kW depends on system direction, shading, inverter clipping (it will be set to do so at just under 4kW unless you asked for DNO permission), temperature.   Pic?

 

The fusing issue may or may not be related.  What exactly trips - solar or whole house?  Is this an RCD or RCBO in your consumer unit, or something else  - pic? 

 

 

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You could read your main meter, a week later read it again.

Isolate PV, leave a week and read meter again.

See what the difference is (hope the weather/cloud cover is similar.

If you have a high and consistent base load, much of your PV generation will be satisfying this.

Your Inverter should also have some logging options in it, this can tell you an awful lot.

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With 6.2 kw of panels they will only generate a peak of 6.2kw of energy under standard conditions. You have a 6.2kwp system where the potential peak power is 6.2kwp. Youll only likely achive this if ALL the panels are square on to the sun around midday in the height of summer, unshaded. If the panels are dirty, part shaded, at the wrong angle, split so they are facing different directions, they wont ever generate 6.2kw.

 

Having optimisers helps with overall production but it wont make a panel or panels generate as normal if they are shaded/dirty.  With a system not fitted with optimisers(or micro inverters) if one panel is shaded/dirty it reduces the generation of all the panels. With optimisers only the shaded/dirty panels reduce in output whilst the remaining panels produce as normal so overall system production is increased compared to a system without optimisers. If youve got a tree/trees shading some panels then youre not going to see 6.2kw.

 

You say that something never "fuses" when the circuit with the inverter is switched off. Why is that circuit switched off as it should be on all the time. What is it that "fuses" when the circuit is on? Does the unit that fuses have a test button on the front of it?

 

Do you know how much you generate each month and how does that compare to the figures in the forecasts you posted?

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7 hours ago, dnoble said:

Having measured the shading and applied the additional coefficient due to the proximity of the tree to the South East, the following graphic show a realistic generation that can be expected from your system under the current conditions

Can you elaborate on these comments from your installer / commissioning agent?

 

5 hours ago, dnoble said:

There was a complication in that they needed some kind of gismo in the loft which needed another electicity supply to run so I elected not to bother with any of that (I tend to avoid unnecessary complication/tech) and I was told it wouldn't make any differnce to performance.

This was for the modbus unit to give you full scale monitoring and better remote access /.system “readability”. You say they needed it, so why did you elect not to bother with it?

 

5 hours ago, dnoble said:

They have "tigo optimisers" which were supplosed to correct probs with performance due to shading etc

They do not correct problems with shading, they maximise the amount of solar revenue when parts of the array are suffering from shading. 
 

4 hours ago, MikeSharp01 said:

Sounds like one of the strings is not working as you are getting about 50% of the expected output and your system is in two strings?

If the modbus was installed this would be easy to identify. Prob good to be sure the inverter is a ‘dual string’ inverter too. @dnoble is this the case?

Edited by Nickfromwales
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3 minutes ago, Carrerahill said:

Perhaps the OP @dnoble could start by answering the above and posting some photos then we can start to chase this down.

 

Unless I am mistaken we still don't actually have a system breakdown, just snippets of information in insolation, and as a group we are going round in circles with the same thoughts and assumptions. The OP is looking for a specialist, I doubt he needs a specialist as the collective minds of this forum can almost certainly unravel the details here with the only exception being if we do decide there is an issue. 

 

OP states that the panels were self-installed, so all the details must be easy enough to list.

 

I posted what I think is a good starting point and it appears to have fallen into the ether. 

 

I think it is fair to say that when people take their time to answer it is worth exploring said answer or at least acknowledge it.

 

Rant over.

Agreed. I feel.like we have been drip fed a partial story on this thread. I'm curious as to why the installer who revisited to confirm there are no issues seems content all is fine. If you look at the graphs he produced they indicate a total daily production of 590kWh for July - so 19kWh for the day. With a 6kWp system this number seems to suggest that current production levels are what is expected?

 

More to this story than we are being told.

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Sounds like you've got the Tigo TS4 modules on each panel, but then you haven't got the gateway that they are suppose to all connect back to in order to work even connected up, so at the moment those Tigo modules will be doing absolutely zero. It needs the gateway in order to know which panels are dragging the string down due to shading.

 

Wire the gateway up, get all the modules connected and then monitor it.

 

The tripping needs investigation, I'm not an electrician, however I don't think a fault DC side would cause a trip AC side, so its more than likely something on the inside wiring. I had a very similar issue for many years when I had solar installed, always seemed to happen Nov/Dec when generation was low and it was damp. In my case it turned out to be nothing to do with the solar farm, it was a cable on the main ring main which had been sliced clean, and someone had just taped it together with fabric tape!! All wiring now replaced and it hasn't tripped for years, nothing was changed on the solar.

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54 minutes ago, Carrerahill said:

Can we get photos of the install?

I edited my own post to add the above line and seem to have deleted the original post, I shall post again below:

 

Perhaps the OP @dnoble could start by answering the above and posting some photos then we can start to chase this down.

 

Unless I am mistaken we still don't actually have a system breakdown, just snippets of information in insolation, and as a group we are going round in circles with the same thoughts and assumptions. The OP is looking for a specialist, I doubt he needs a specialist as the collective minds of this forum can almost certainly unravel the details here with the only exception being if we do decide there is an issue. 

 

OP states that the panels were self-installed, so all the details must be easy enough to list.

 

I posted what I think is a good starting point and it appears to have fallen into the ether. 

 

I think it is fair to say that when people take their time to answer it is worth exploring said answer or at least acknowledge it.

 

Rant over.

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