7.5 kw setup self install help needed

[umer]

hi everyone,  i am new on this forum and still looking for information on diy solar install

i have a survey done of my house by a solar installer and they said that i can have 14 panels installed in two rows max. but the estimate they gave me 

is almost 100 percent more than what i can buy myself even after paying vat from online stores like ITS. So naturally i got confused because even after getting hardware without vat these

companies are quoting prices like that. i am off work now and have lot of free time and diy experience . if i can get some help from experienced folks here than i can take it on with the help of a local electrician.

 

My yearly electric usage is 5000 kwh aprox and i plan to remove gas totally and have air to air heat pump /air conditioner for heating and 

immersion heating for hot water. also, we are planning to get an ev later. So i wanted the maximum energy generation from the solar. 

i am   looking at ja solar 545 half cell panels with a gsl battery all in one system or any other setup you can advise.

please advise me for a setup including all the mounting, cables, isolators etc and the costs involved please.

 

the quote i got from the solar company is 10,300 for 14 ja solar 545 half cell perc panels and 6 kw solis hybrid inverter. 3400 extra for an ac battery. 

 

please advise me 

 

kind regards

umer

[Dillsue]

Before you go too far designing/buying kit, if youre looking at a 6kw inverter youll need permission from your DNO so probably worth speaking to them to check you can connect a 6kw system to the grid.

[Marvin]

29 minutes ago, Dillsue said:

Before you go too far designing/buying kit, if youre looking at a 6kw inverter youll need permission from your DNO so probably worth speaking to them to check you can connect a 6kw system to the grid.

Hi @umer

 

This can take a few months to get a reply from your DNO. It took about 2 1/2 months for us and a £360 fee.

[jayc89]

54 minutes ago, Dillsue said:

Before you go too far designing/buying kit, if youre looking at a 6kw inverter youll need permission from your DNO so probably worth speaking to them to check you can connect a 6kw system to the grid.

 

Is this true even if you don't plan to feed back to the grid?

[umer]

14 minutes ago, jayc89 said:

 

Is this true even if you don't plan to feed back to the grid?

I had this question in my mind too.what if don't want to export. Also does a 5 kw needs dno too?

[umer]

37 minutes ago, Marvin said:

Hi @umer

 

This can take a few months to get a reply from your DNO. It took about 2 1/2 months for us and a £360 fee.

So that's 360 added to cost. Can we apply before installing?

[S2D2]

2 hours ago, umer said:

10,300 for 14 ja solar 545 half cell perc panels and 6 kw solis hybrid inverter

Quote seems a couple of grand heavy, might be worth getting a few more but prices are getting a little daft atm. Remember it includes a whole bunch of other kit, mountings, cables, scaffolding etc. And will give you an MCS certificate to get paid for export. Even with your high usage you may end up exporting a fair chunk. 

[umer]

Let's try want to justify the 10000 plus quote .I can buy the panels and inverter from ITS FOR 5000. What else I need. How much scafolding will cost for this house. It's a semi detached with extension on side. And how much should I add for cabling,isolaters, mounts etc.

 

[ProDave]

1 hour ago, umer said:

I had this question in my mind too.what if don't want to export. Also does a 5 kw needs dno too?

YES.

 

I have a pretty standard 4kW panels and 3.68kW inverter, but when I submitted my paperwork (pre G98, I forget which) I got an almost instant reply to disconnect it immediately and apply for approval (what would have now been G99)  And telling me there would be a fee for even applying.

 

In my case they had seen the inverter model number which contained "4000" and assumed it was a 4kW inverter not 3.68kW and were demanding prior approval, even though that would only have been slightly over 3.68kW.

 

Sending them the paperwork for the inverter confirming it's output was limited to 3.68kW sorted the issue, but it showed there is no leeway.

 

To date in over 3 years I have only exported just over 300kWh.  the fact you don't intend to export is irrelevant, the fact is you could.

[umer]

5 minutes ago, ProDave said:

YES.

 

I have a pretty standard 4kW panels and 3.68kW inverter, but when I submitted my paperwork (pre G98, I forget which) I got an almost instant reply to disconnect it immediately and apply for approval (what would have now been G99)  And telling me there would be a fee for even applying.

 

In my case they had seen the inverter model number which contained "4000" and assumed it was a 4kW inverter not 3.68kW and were demanding prior approval, even though that would only have been slightly over 3.68kW.

 

Sending them the paperwork for the inverter confirming it's output was limited to 3.68kW sorted the issue, but it showed there is no leeway.

 

To date in over 3 years I have only exported just over 300kWh.  the fact you don't intend to export is irrelevant, the fact is you could.

I will call them tomorrow.but who to call, my energy supplier that is eon next at the moment or someone else?

[Dillsue]

Call your DNO, the company that fixes blackouts, not your supplier

[Dillsue]

14 hours ago, umer said:

Let's try want to justify the 10000 plus quote .I can buy the panels and inverter from ITS FOR 5000. What else I need. How much scafolding will cost for this house. It's a semi detached with extension on side. And how much should I add for cabling,isolaters, mounts etc.

 

If your panels are going on the front of the house, how much shading is that tree casting over your roof?

[Dillsue]

15 hours ago, umer said:

So that's 360 added to cost. Can we apply before installing?

There's been posts saying that some DNOs dont charge for a G99 so you may get lucky. SPEN, our DNO charged us £300.

If you start installing a 6 kw system and your DNO says you can't have that much, youre going to be in a pickle. Speak to them before you start buying gear and they may give you an informal answer quite quickly. SPEN told us informally within a few days that we could double our output. Formal application took a couple of months to process.

[joth]

If you want to avoid the DNO G99 runaround, it's probably fine putting 5kW of panels on a 3.68kW inverter (solaredge HD wave 3680 can take up to 5.7kW on the DC side, for example).

This will loose a bit of peak generation in summer, but odds are that'd just be exported for no personal gain anyway 

But if you then add a DC coupled battery (and even, DC coupled EV charger) then the excess generation will go into usefully charging that. 

 

Edited November 28, 2022 by joth

[umer]

2 hours ago, Dillsue said:

If your panels are going on the front of the house, how much shading is that tree casting over your roof?

None at all. But I will trim it from top if it did.

[Marvin]

1 hour ago, joth said:

If you want to avoid the DNO G99 runaround, it's probably fine putting 5kW of panels on a 3.68kW inverter (solaredge HD wave 3680 can take up to 5.7kW on the DC side, for example).

This will loose a bit of peak generation in summer, but odds are that'd just be exported for no personal gain anyway 

But if you then add a DC coupled battery (and even, DC coupled EV charger) then the excess generation will go into usefully charging that. 

 

Hi @joth

 

That's good info and thoughts!

 

We know our inverter will allow just under 8kW of panels and we are going to increase them at some stage.

 

M

[umer]

I spoke to my dno and they asked me to fill online form .also it says online that Upto 5 kw approvals will be given with out visit. Also they are asking for following docs for application. see the screen capture please. What's are these documents. does location plan means the house plans?

[Marvin]

1 Street plan showing location of property and full postal address.

 

2 plan of your property.

 

3 technical specification of the inverter you are proposing to install. 

[Marvin]

Hi @umer

 

They want to know where you are and what your connecting is limited to what your asking for.

My rough plan showed the outside of the house and boundaries, where the panels were to be on the roof, where my consumer unit was and where the inverter was going to be. With brief description eg:

panels here on front roof.

Mains supply to here in the garage 

Inverter here in loft.

With arrows.

 

 

Edited November 28, 2022 by Marvin
Add info

[Dillsue]

I think you maybe looking at the wrong form! It's G99 A1-1 that you want. Certainly for my application there was no site or location plan needed. To go with the form youll need a single line drawing of the house electrics and a type test certificate for the inverter which youll get from the ENA inverter database

[Marvin]

Just now, Dillsue said:

I think you maybe looking at the wrong form! It's G99 A1-1 that you want. Certainly for my application there was no site or location plan needed. To go with the form youll need a single line drawing of the house electrics and a type test certificate for the inverter which youll get from the ENA inverter database

From discussions here, I think different DNO's want different things so I would double check.

[Marvin]

Hi @umer

 

My DNO's response June 2021:   

 

Good Afternoon

 

Thank you for getting in touch.

 

The below is the criteria required to apply.

 

If you would like a formal connection offer and are applying for a generation connection of 50kW or less then this will be dealt with through our Microgeneration Team. You would be required to submit a Completed G99 A1-1 form, which I have attached for you. You will also need to provide the following supporting documents;

 

• Site Plan – Please show the site boundary and proposed new supply location.

 

• Schematic – Please show the name & size of inverters being used, a clear demarcation between the DNO and customer equipment and the generation itself.

 

• G99 Type Test Certificate
• LOA – Please provide a signed letter of authority dated within the last 12 months (if the landowner is applying please state this in the application/email).

 

Some of this information you will be best to get from your appointed installer.

 

Once you have everything you need, you can email north.Microgen@sse.com or south.microgen@sse.com where your application will be reviewed and registered. If you have everything required to make your application competent then it will be passed onto our Network Designer for quotation. You will receive this within 65 working days .

 

Please be aware that Connection Offer Expenses, where applicable, will be due to be paid for the provision of this Connection Offer. Where applicable this will be payable even if you do not wish to accept your Connection Offer. If you cancel your applications within 14 days you will not be liable for any Connection Offer Expenses. However where applicable, if you cancel after this point you will be required to pay the full amount. For further information on Connection Offer Expenses, including where charges are applicable, you can find our Connection Offer Expenses user guide here. (https://www.ssen.co.uk/connections/usefuldocuments/)

 

If you are applying on behalf of an ICP or IDNO please let us know.

 

Please do not hesitate to contact us at mcc@sse.com or on the telephone number below if you have any problems or queries.

 

Many Thanks

 

Edited November 28, 2022 by Marvin
Clarification

[Dillsue]

24 minutes ago, Marvin said:

From discussions here, I think different DNO's want different things so I would double check.

Id not picked up on people being asked for a site layout so definitely worth checking

[bertybuttface]

11 hours ago, joth said:

If you want to avoid the DNO G99 runaround, it's probably fine putting 5kW of panels on a 3.68kW inverter (solaredge HD wave 3680 can take up to 5.7kW on the DC side, for example).

This will loose a bit of peak generation in summer, but odds are that'd just be exported for no personal gain anyway 

But if you then add a DC coupled battery (and even, DC coupled EV charger) then the excess generation will go into usefully charging that. 

 

If you can prove your inverter is both limited to 0 watt export and has never exported any power do you still need a G99?

[Dillsue]

8 hours ago, bertybuttface said:

If you can prove your inverter is both limited to 0 watt export and has never exported any power do you still need a G99?

How are you going to prove it?

 

From conversations Ive had with our DNO the way that they expect you to prove it is make a G99/G100 application and they then come out and witness the limitation system, all chargeable!