Which set up 3.6kw or 5kw inverter

[margo]

I had a few quotes but going to choose in between two. I would be forever grateful if someone could help me, as I don't know which inverter is going to be best. Both quotes are for 12 panels + 4 optimisers (for shaded area)

Company no 1.
3.6 kw hybrid giveEnergy inverter
GiveEnergy 9.5kw battery

Company no 2.
5kw lux power Inverter
9.6 kw innovation battery

Thank you

 

[johnb2713]

Definately need to go bigger than 3.6kW which points you towards option 2, I have no experience of lux power or giveenergy so maybe some of the others will comment.

 

[wc1966]

I have the 5kw GivEnergy Gen 3 inverter, this has a 3.6kw peak charge current which is higher than earlier models.

I have 19 panels, in my case I didn't bother with optimisers are I have very little shading. Carefully consider this in your ROI calcs

 

[binky]

company 1 can't be bothered to do a DNO application ofr over 3.6 kw connection

company 2 can be bothered to do the above, so probably the btter option dependent on prices of course.

 

[margo]

company 1 can't be bothered to do a DNO application ofr over 3.6 kw connection

company 2 can be bothered to do the above, so probably the btter option dependent on prices of course.

There is very little price difference but Company number 2 is cheaper .
I've asked Company number 1 why only 3.6kw and he replied that is better if inverter works harder and longer

 

[margo]

I have the 5kw GivEnergy Gen 3 inverter, this has a 3.6kw peak charge current which is higher than earlier models.

I have 19 panels, in my case I didn't bother with optimisers are I have very little shading. Carefully consider this in your ROI calcs

I will have shading from the chimneys. On both sides at some point of a day. I don't want to make mistake with inverter. I'm so confused and there is no clear answer on Internet. My friend has also 12 panels + 4.2 kw Inverter

 

[johnb2713]

There is very little price difference but Company number 2 is cheaper .
I've asked Company number 1 why only 3.6kw and he replied that is better if inverter works harder and longer

That rules out company No.1, it's male cow manure.

 

[johnb2713]

I will have shading from the chimneys. On both sides at some point of a day. I don't want to make mistake with inverter. I'm so confused and there is no clear answer on Internet. My friend has also 12 panels + 4.2 kw Inverter

The panels are connected together like a chain, and just a chain, it's only as strong as it's weakest link. If you have say 8 panels in a string (chain) and one panel has shadows on it, the whole of the string's performance will be reduced to that of the shaded panel. You can have optimisers fitted to resolve that issue but it needs sorting.

 

[wc1966]

The panels are connected together like a chain, and just a chain, it's only as strong as it's weakest link. If you have say 8 panels in a string (chain) and one panel has shadows on it, the whole of the string's performance will be reduced to that of the shaded panel. You can have optimisers fitted to resolve that issue but it needs sorting.

I think with shading you have to consider when it occurs. For me it would only occur in the darker 6 months when I expect only 25% of energy is created. I decided the additional cost was not worth it, I sank the money into extra panels instead. Also optimisers are a point of failure and replacing them isn't easy.

Gary does Solar has a good analysis on them....

 

[margo]

I think with shading you have to consider when it occurs. For me it would only occur in the darker 6 months when I expect only 25% of energy is created. I decided the additional cost was not worth it, I sank the money into extra panels instead. Also optimisers are a point of failure and replacing them isn't easy.

Gary does Solar has a good analysis on them....

Thank you.. 12 panels is maximum I can fit on the sunny side of my roof . I could possibly have another 2-3 on the other side , but very little sun ( if any?) . I think 4 optimisers £1200 . And it was upon my request .. I've read that if you have shading, it can mess with the whole system..

 

[johnb2713]

I think with shading you have to consider when it occurs. For me it would only occur in the darker 6 months when I expect only 25% of energy is created. I decided the additional cost was not worth it, I sank the money into extra panels instead. Also optimisers are a point of failure and replacing them isn't easy.

Gary does Solar has a good analysis on them....

Not a bad explanation but losing 50% of a panels capacity due to shading would annoy the hell out of me. Fortunately, I dont have any shading my system so no need for optimisers.

 

[binky]

What that video doesn't discuss is that the diodes are the weakest point, and eventually fail, albeit many years down the line. So optimisers actually protect the diodes, and when they eventually fail, are easier to replace.

 

[wc1966]

Thank you.. 12 panels is maximum I can fit on the sunny side of my roof . I could possibly have another 2-3 on the other side , but very little sun ( if any?) . I think 4 optimisers £1200 . And it was upon my request .. I've read that if you have shading, it can mess with the whole system..

So you've got 5kw of panels, you will actually clip and I'm not sure you will that much even if you were limited to 3.6

I've got 8kw of panels and 5kw inverter, 6 weeks into the game and I'm finding I don't actually clip that much. I negate clipping on good days by delaying my battery charging until I'm into the clipping zone (roughly 2.5 hours before solar noon I exceed 5kw)

 

[margo]

company 1 can't be bothered to do a DNO application ofr over 3.6 kw connection

company 2 can be bothered to do the above, so probably the btter option dependent on prices of course.

So I have emailed both, and the owner of company number 2 has called me this morning and explained everything, and like you said, he mentioned that they have to apply for DNO . He said its lots of pages and people can't be bothered so they offed 3.6 kw inverter. But he said I would be loosing too much , therefore I need 5kw .

 

[truffle pig]

12 panels, but of what size? ie, what is the total output of the system? ie:-
12 x 335w = 4.02kw - put it on a 3.6 with a g98 application - company 1
12 x 425w = 5.1kw - put it on a 5.0 with a g99 application - company 2

it is suggested that undersizing the inverter by 10 - 20% ish can give you a better total yield over the day Although the peak power may be clipped they are more efficient at lower inputs.
I would be more interested in the sort of job they are going to do - is there any installs you can look at / talk to? good recommendations are worth their weigh. good luck

 

[binky]

So I have emailed both, and the owner of company number 2 has called me this morning and explained everything, and like you said, he mentioned that they have to apply for DNO . He said its lots of pages and people can't be bothered so they offed 3.6 kw inverter. But he said I would be loosing too much , therefore I need 5kw .

Sounds like a decent company, use them.

 

[binky]

12 panels, but of what size? ie, what is the total output of the system? ie:-
12 x 335w = 4.02kw - put it on a 3.6 with a g98 application - company 1
12 x 425w = 5.1kw - put it on a 5.0 with a g99 application - company 2

it is suggested that undersizing the inverter by 10 - 20% ish can give you a better total yield over the day Although the peak power may be clipped they are more efficient at lower inputs.
I would be more interested in the sort of job they are going to do - is there any installs you can look at / talk to? good recommendations are worth their weigh. good luck

That's old hat from when inverters were less efficient and efficiency could drop off to around 70%. Current inverters don't drop below around 92% efficiency. So I would only be looking at undersizing purely because of the inverter sizes themselves, ie you have say 5.2kw of panels, so a 5kw inverter would suit the array

 

[margo]

Two proposals, please let me know what you think. Thank you

 

[johnb2713]

The second one, absolutely no doubt.

 

[Lydanial]

Hi Margo,

Do you mind me asking who is quoting you (can private message if you don't want to say on here)...

I've ended up with 13 quotes (don't ask)...