My Solar setup, am I using it efficiently ? Luxpower ACS3.6

Starfrog

I have had my solar setup since Feb 21 and I've been happy with it but I get clipping and wanted to know how best to maximise my setup or is it fine as it is. I have 12xJa Solar panels 455w each (5460w total) and they in turn are connected to Enphase IQ7+ microinverters, when I use my enphase solar production monitor I always see clipping at 3.5kWh on sunny days from fairly early on till late in the day of sunshine (especially in summer). My Enphase always shows me more production than my Luxpowertek Hybrid 3.6 inverter portal, The highest day production I ever had was this year on June 2nd with a total of 34.2kWh of solar production (as per the Enphase portal) and on the Luxpower portal it says I produced 30.2kWh which is quite a bit less but Im thinking that maybe its normal for it to show about 10% less due to loss from panel to the inverter ? (this is what Im trying to find out as thats a lot over a year ?). 

the enphase solar production gets to 3.5kWh at any one time in the portals but thats it clipping as its just a flat line and in my Luxpowertek it says its on average around 3.12kWh. I think that there is a bottleneck between the solar panels and the microinverters that they can only pass to the luxpower up to 295w (12x 295w = 3540w)  from the panel of 455w ? So would it be worth me upgrading my Microinverts to ones that can give me more power from the panel up to the max that the panels give ? but If I do that does the Luxpowertek then become the bottleneck in that it cant take more than 3.6kWh ? 

What Id like to ultimately achieve is have a setup that can on a good sunny day not do any clipping and give me as near the theoretical limit of the solar panels production of 5,460kWh ? how can I achieve this and would it be worth the cost to upgrade microinverters and main inverter ? (taking into consideration I have about 25 years of life ahead and to be missing out on potentially around 2000kWh of potential production each sunny day maybe it would be worth it (id maybe sell the old equipment to reduce the costs.

as I side note in the year 2021 minus January for 11 months up to december I produced 4.2mWh and for 2022 so far ive produced 3.5mWh so a total of 7.7mWh since feb 2021 to present. I also have the setup tied to a pylontech 12kWh battery array. 

Thanks in advance for any insight that people are able to give 

Alnat1

I have a fairly similar set up minus the Enphase IQ7+ microinverters. For me 5.25 on the roof, Lux hybrid 3.6 and 4.8 pylontechs.

To help the clipping I change the "system charge power rate%" to 0 in the morning on the Lux portal which stops the batteries charging. I then turn it back to 100% (around midday for me with a SW facing roof) when the system is starting to cap at 3.6kWh. This allows more power to come off the roof until the batteries have filled as the 3.6 cap is only on what comes out of the inverter on the load/grid side.

If I'm around at home with a bit more time to keep tabs, I might gradually raise the %, 25%, then 50% as my batteries soon fill. You have more so it's learning how long yours will take and at what time your system reaches max output.

I'm not very technical so this is a very simple explanation of what works for me.

Reed_Richards

Starfrog said:

What Id like to ultimately achieve is have a setup that can on a good sunny day not do any clipping and give me as near the theoretical limit of the solar panels production of 5,460kWh ? how can I achieve this and would it be worth the cost to upgrade microinverters and main inverter ? 

Presumably when your installer applied for DNO approval they applied for the maximum 3.68 kW of export for which there is automatic approval.  To ensure this is achieved you have an inverter that will give a maximum output of that 3.68 kW (the clue is in the name, Luxpower ACS3.6). This should have been explained to you at the time you were given your quote.  To reach the theoretical limit you would need to apply for DNO approval to export more and then swap your inverter for one that is capable of that.

I doubt that you have much domestic use that would require the full output of your panels and only Octopus pay enough (on one particular tariff) for exported electricity to make any change potentially worthwhile.     

QrizB

It took me a couple of goes to get my head around your set-up, but I think I've got it now.

Your generation is limited by your Enphase microinverters. Regardless of how bright and clear the day is, you're not going to be able to generate more than 3540W.

The choice of 295W microinverters for use with 455W panels is an unusual one. Your installer should have talked you through the pros and cons before you committed to this. Did you get this information at the time?

Your Lux inverter is not a hybrid. Per the subject line it's an ACS 3600 which is an AC-coupled inverter. As a result the maximum charge rate the Lux can achieve (without resorting to importing power from the grid) is 3540w less whatever your domestic load is at the time. This will be why you're seeing a plateau at 3.1kW or so.

To get more power from your roof you'll need to replace the Enphase microinverters, either with more powerful ones (from Enphase if they make them, or another supplier of they don't) or with a conventional string inverter. This will then move the bottleneck to the 3.6kW rating of the Lux, but will allow you to export any surplus. It will also need a new G99 application to your DNO, which might prove to be an obstacle. Again, what discussions did you have with your installer about this when your system was installed?

Finally, all this is likely to cost a low four figure sum once you factor in parts, scaffolding and labour. Is it worth that much to you?

Starfrog

Thank you for the feedback and its given me clarity as to what my options are. The installers did mention at the time the micro inverters would be a factor as I insisted on having 455w panels but my thought process on that was as panels degrade over the years that ultimately I shouldn't see much degradation in my performance of the setup as I had enough extra capacity from the panels. I understand that the max I can dump to the grid is the 3.6 due to the DNO, (would luxpower inverter be able to accept more than 3.6 from the panels or is that a limit as well to avoid me not having any house consumption and it all going to the grid ?) 

The reality is if i want more power from the panels I would, as Qrizb mentioned need to update the microinverters with something that allowed for more power to be sent to the Luxpower main inverter. The reason I choose the enphase was I didnt like the ideo of a single point of failure in my array and the enphase have good reviews about lifetime performance. 

the cost of new microinverters, main inverter etc is probably not worth the cost but with the electric prices as they stand its not far off !! 

one scenario that I thought about was if I swapped out the microinverters for something that gives me full access to the solar array output of 5460kWh would the Luxinverter accept that additional power and dump it to my batteries at a higher rate than 3.6 I think the Output to the grid is fixed at 3.6 but maybe to my home consumption and the batteries it might be capable of more ? 

I'm still curious as to why my enphase portal says 3.5  but the lux says about 10% less ? 

overall I'm happy with the performance so just wanted a sanity check on if there were any obvious settings I could change. 

Thanks all for your feedback  



  

Heedtheadvice

Well I guess (QrizB haveing it correct) that I would have made a different selection of system components unless of course you needed microinverters because of shading or other technical issues. That coukd have allowed you to use a hybrid inverter and charged the batteries more (potentially) direct from the panels' dc output which would better use the peak generation.

However all is not bad news. The seemingly excess power that is not being utiised is a downside but is also a big plus at lower at lower generation levels. So you will be getting better generation early and late in the day plus better generation in cloudier weather and late autumn through to early spring.

It could also be that you might not get approval for G99. Info from another Scottish poster told me he had been refused and that might apply to you. I could be wrong here but I reckon the reason being that the grid in Scotland already has difficulties coping with all the renewable generation, hence the reason for all the upgrades of lines (such as Beauly to Denny and others) to send power from generators to users. The country's power generation by renewables currently matches consumption (5Gw) and the lines cope with that plus the export and import required at times. At Lochinver you are a long way in transmission terms from the main destinations so that might be problematic.......just a guess but a G99 application might be money wasted!

QrizB

Sorry, one more thought. (Correct me someone if I've got this wrong.)

As your Lux could, in principle at least, export at 3.6kW at the same time as your panels are generating their 3.54kW,  I think your installer should already have made a 7.2kW G99 application for your system.

I suspect that they didn't, but your paperwork should confirm this one way or another.

Starfrog

QrizB said:

Sorry, one more thought. (Correct me someone if I've got this wrong.)

As your Lux could, in principle at least, export at 3.6kW at the same time as your panels are generating their 3.54kW,  I think your installer should already have made a 7.2kW G99 application for your system.

I suspect that they didn't, but your paperwork should confirm this one way or another.

I have a G98 for my setup