4.57Kw PV with a 4Kw inverter. Inverter too small?

[v lowery]

have checked company paperwork and it says savings of up to 25% and old inverter ok.

 

[Startinez]

From my recollection, the inverter should be down-rated from the maximum generation. If the system actually hits 3.98kW, I believe that's too close. I'll double check my notes on it tomorrow and let you know.

It is in fact the other way round. You are allowed an inverter underrating of 80% and not that you should allow 20% extra over Wp rating.

 

[v lowery]

It is in fact the other way round. You are allowed an inverter underrating of 80% and not that you should allow 20% extra over Wp rating.

 

[v lowery]

don't know what this means, but they say on site 25% increase in electric.

 

[Gavin A]

hi, I have solar panels 7 years, for the last 2 years I have solaredge upgrade and I have my yearly data the last 2 years are worse than my original set up. I am not seeing the 20% raise in electric as promised. checked weather patterns and we do seem to have had 2 years with 20% less light. any thoughts. solaredge cannot see I problem, I can as I have lost £2600 plus yearly interest for something that is losing me money.

unfortunately you've been ripped off, there was never any chance of a 20% increase in generation unless your previous system was heavily shaded and using a poorly performing inverter in the first place.

Please complain to trading standards about the company who mis-sold you that 'upgrade'.

 

[Bobster]

unfortunately you've been ripped off, there was never any chance of a 20% increase in generation unless your previous system was heavily shaded and using a poorly performing inverter in the first place.

Please complain to trading standards about the company who mis-sold you that 'upgrade'.

He wont get anywhere with complaining to trading standards, they stated 'up to' which is as good as saying, you're not going to get anything.

As for the performance issues, I've seen a 10% reduction in power production just with having a fine layer of dust on the panels. Fine this was on a site generating 80MW, but the principal is the same.

 

[v lowery]

unfortunately you've been ripped off, there was never any chance of a 20% increase in generation unless your previous system was heavily shaded and using a poorly performing inverter in the first place.

Please complain to trading standards about the company who mis-sold you that 'upgrade'.

thanks for info.

 

[v lowery]

He wont get anywhere with complaining to trading standards, they stated 'up to' which is as good as saying, you're not going to get anything.

As for the performance issues, I've seen a 10% reduction in power production just with having a fine layer of dust on the panels. Fine this was on a site generating 80MW, but the principal is the same.

thanks for message, yes it said up to 25% but 3 of the first 5 years are better than the last 2 years with solar edge, there,s only 120 kwhs between my best year and worst, also its strange I would have dust only the solar edge years?. I will just go to smalls claims court thanks for info about trading standards.

 

[Bobster]

thanks for message, yes it said up to 25% but 3 of the first 5 years are better than the last 2 years with solar edge, there,s only 120 kwhs between my best year and worst, also its strange I would have dust only the solar edge years?. I will just go to smalls claims court thanks for info about trading standards.

I wasn't suggesting that the panels being cleaned was your issue. Just pointing out that poor maintenance can reduce their output over time.

 

[v lowery]

I wasn't suggesting that the panels being cleaned was your issue. Just pointing out that poor maintenance can reduce their output over time.

i know thanks, but 2 years ago they cleaned panels when fitting system and panels are self cleaning" if you believe paperwork". cheers Rob.

 

[Bobster]

i know thanks, but 2 years ago they cleaned panels when fitting system and panels are self cleaning" if you believe paperwork". cheers Rob.

Self cleaning only stops mold and algi growing on the panels.

 

[v lowery]

Self cleaning only stops mold and algi growing on the panels.

thanks for that Rob I now know to, believe nothing a solar salesperson says or the claims they make on paper.

 

[tlsambo]

hi, I have solar panels 7 years, for the last 2 years I have solaredge upgrade and I have my yearly data the last 2 years are worse than my original set up. I am not seeing the 20% raise in electric as promised. checked weather patterns and we do seem to have had 2 years with 20% less light. any thoughts. solaredge cannot see I problem, I can as I have lost £2600 plus yearly interest for something that is losing me money.

Unless you have severe and i mean SEVERE shading you won't see a 20% increase from a Solar Edge system. More likely to be 2-5% depending on the degradation of your panels. Solar Edge helps to make up for the natural differences in each individual panel's output as they'll degrade at different rates. Unfortunately Solar Edge is often mis-sold with the classic broadband statement of 'up to' 20% increase in yeild. If your installer isn't using either PV Sol or PV Syst software to calculate the yeild then the figures won't be accurate.

 

[tlsambo]

thanks for that Rob I now know to, believe nothing a solar salesperson says or the claims they make on paper.

We've been carrying out a cleaning experiment on a Solar Edge monitored system so we can compare panels performance side by side. We clean one panel every 2 months, one every 6 months and one is left dirty. The difference in performance is around 0.3%.

 

[mrbroons]

As far I have read over supplying the inverter is done to assist with Winter generation. The inverter should clip the output to 3.68 kw see the following for the guidelines Western Power Distribution - G59 Connection procedure - https://www.westernpower.co.uk/Connections/Generation/Installation/G59-2.aspx. If a system was installed with 3.68kw of panels it would never see that value due to loses and non perfect generation conditions. So it is possible to over supply the inverter to effectively maximise the available generation throughout the year without tripping the G59 limitation. The inverter will simply cap or clip the generation to the value specified regardless of the panels attached (assuming they are within the inverter max spec) but this will mean that you will more often be generating a higher value rather than very rarely if ever getting near the rated capacity of the install.