Adding additional PV + battery and quotes are all over the place

ccbrowning

We are looking at expanding on our current PV installation and also add some battery storage so have gotten a few quotes. However, they are all very different! I can put the three up later, just have to format all of the data. House is pretty new and 100% electric including GSHP and 300l immersion tank.

Current state:

• 11 x 310W JA Solar panels for 3.41kW, GSE mounted. 169S/SE and gets some shade as the sun moves due to our weird roof architecture.
• Growatt 3000-S
• I think it's just a single string inverter?

Main differences:

• Only one is recommending any panels on our garage due to shade as the sun moves and requiring optimisers to really make use of the panels
• One recommends updating the existing 11 to use optimisers and fitting a new (SE6000H) for the existing 11 and new 10x400W panels
• Yet another is saying to leave the existing installation alone and have a separate 3.6kW hybrid inverter just for the 10 additional panels. No optimisers at all

Any idea when optimisers make sense/don't make sense and when it makes sense to update and existing setup?

Available roof (all east or south-east):

• 77E/NE Roof: That can fit up to 10 panels
• Garage: 169 S/SE (same as existing)- space for up to 6 panels, but will get some shade as the sun moves, from the adjacent SE roof.

Reed_Richards

Any issues with FIT?  If you get that now and modify your system you would lose it, I believe.  And do you think you would get DNO approval for your additional export capability?  Sorry, this does not answer your question on which to chose but these are important considerations which your first post did not cover.    

ccbrowning

Reed_Richards said:

Any issues with FIT?  If you get that now and modify your system you would lose it, I believe.  And do you think you would get DNO approval for your additional export capability?  Sorry, this does not answer your question on which to chose but these are important considerations which your first post did not cover.    

It's a fairly new build, so only SEG to consider not FIT. We will need DNO approval, but not sure if we will get it? Not sure how you can determine that in advance or not. All the suppliers were up front about needing this and said it could take up to 60 working days.

The house does have EV charging capability and a GSHP (with its own MCS), but I think we still just have a single phase supply currently. I see two boxes with 100A on the by the meter, one of which is the 'on off' to use before working on our electrics.

Edit: I've been told this re: DNO "when using Solar Edge the DNO will always agree as we can restrict the export is required."

Reed_Richards

I imagine the DNO, if they let you export more, would at the very least want to ensure that you don't exceed the capacity of your mains fuse.  Mine was upgraded from 60 A to 80 A (free) when I got an ASHP, except that when the engineer unsealed the box it turned out I already had an 80 A fuse.  There seems to be know way of knowing and no way of telling and any labelling is unreliable.

ccbrowning

I still am getting no consistency. . Here is the back of our house - https://imgur.com/a/UHUwEGa south/southeast on the roof you can see but the right side is east/slightly east north east.

QrizB

ccbrowning said:

I still am getting no consistency. . Here is the back of our house - https://imgur.com/a/UHUwEGa south/southeast on the roof you can see but the right side is east/slightly east north east.

Interesting roof(s).

I'd put a big array on the E-ish facing pitch (I'm assuming no dormers, Velux windows, chimmneys, satellite arrays etc.) with their own inverter, and forget about the garage roof for now.

ccbrowning

QrizB said:

ccbrowning said:

I still am getting no consistency. . Here is the back of our house - https://imgur.com/a/UHUwEGa south/southeast on the roof you can see but the right side is east/slightly east north east.

Interesting roof(s).

I'd put a big array on the E-ish facing pitch (I'm assuming no dormers, Velux windows, chimmneys, satellite arrays etc.) with their own inverter, and forget about the garage roof for now.

Architecturally it is nice, but I think they could have kept a modern look and also been able to handle solar better.

I assume updating the existing 11 to use optimisers, etc., is probably going to be difficult to ever see a real ROI? So far everyone has only quoted 10 on the 'east' roof and I thought it could fit more, but maybe I was wrong.