Solar Panel & Battery Quote Advice

Screwdriva

Martyn1981 said:

40m2+ ....... now we're talking  

So, off the top of my head, and Screwdriva can advise, but testing to the extreme, 10kWp may be ~£7k installed, if no scaffolding needed?

My guess is between 18-22 Eurener 500W bifacial panels will fit on that roof. Cost for a PW3 based system + 20 panels + EV Charger is ~£14.5K via the installers I use, but they only cover England/ E Wales. Scotland is the Wild West and has a high premium to everything sadly, assuming you can find someone willing to install quality kit.

McKnze21

So I used this tool and my house was getting the following…

Yearly PV energy production [kWh]:

966.23

Martyn1981

That's actually higher than I expected. Is your roof closer to south facing than south west? [Edit - If you're quite close to the coast that can also help, with cooler winds improving panel efficiency.]

Now that you've played with PVGIS, you can see it's actually quite simple. Pop the kWp system size in the "Installed peak PV power [kWp]" box when you get quotes, and the guestimate should be quite accurate. But small caveat, it's an average estimate, so some months and years will be more, some less depending on the weather.

Great news, so potentially ~9kWp of PV would generate about the same annually as you consume. But of course, not at the same time, as you will generate more than you need in the summer, and less than you need in winter. But still nice to achieve, and summer export earnings will help with your annual bill.

Now the hard bit, getting some good priced quotes. I wish you the best of luck.

McKnze21

So I have since had a new quote from a different installer, he has provided two proposals... let me know what you think of these please?

£11,800
Solar Panels: 14x Eurener Nexa 475w All Black TopCon Mono
Inverter: G3 GivEnergy 8kW hybrid
Battery: 3x GivEnergy 3.4kWh LiFePO4 HV Stackable
Mounting: Renusol pitched roof mounting system

£13,000
Solar Panels: 20x Eurener Nexa 475w All Black TopCon Mono
Inverter: G3 GivEnergy 10kW hybrid
Battery: 3x GivEnergy 3.4kWh LiFePO4 HV Stackable
Mounting: Renusol pitched roof mounting system

Installation, Bird Protection, Scaffolding, DNO all included.

They did say that they reckon I could easily have up to 28x panels on this roof but their proposal was based on a good balance in terms of price and what's really required. They also said that this is their proposal based on what I have told them as my annual usage is 8585kWh. They advised that if I’d like to explore alternative brands, just let them know and they’ll be happy to provide options.

Screwdriva

McKnze21 said:

They did say that they reckon I could easily have up to 28x panels on this roof but their proposal was based on a good balance in terms of price and what's really required. They also said that this is their proposal based on what I have told them as my annual usage is 8585kWh. They advised that if I’d like to explore alternative brands, just let them know and they’ll be happy to provide options.

A much better quote! 

With the greatest of respect to the installer, I would recommend politely ignoring their definition of a balanced system and going for max coverage of the roof at this initial stage. Let the G99 allowance determine the final # of panels. eg. if you get the full 11kWh allowance, happy days. Otherwise subtract 2 X panels for every 1kWh export allowance lost in the final approval (26 panels for 11kWh allowance, 24 panels for 10kWh, 22 for 9kWh etc.)

I would also ask for the max # of the 500W Eurener bifacial panels and the newly launched GivEnergy All in One (if Tesla PW3 isn't an option). This is an about-to-be launched 13.5kW PW3 competitor that should prove less expensive than 3 separate battery banks and a standalone inverter. If it means delaying your installation by a few weeks, I'd recommend this as the most future proof path forward. 

McKnze21

GivEnergy All in One only has up to a 6kW inverter if I am not mistaken? As opposed to the inverters above which as 8kW & 10kW, albeit it they mayu come in more expensive. In that case, would it not be best focusing on the Tesla PW3? Obviously this is all dependant on the DNO G99 allowance though

McKnze21

My apologies, I obviously wasn't looking at the correct one and I presume you were referring to the GivEnergy All In One 2 which has up to 12kW. I can't actually see if this has been released or not yet though

McKnze21

So apparently my roof can accommodate up to 28 panels.

If I was to go for max coverage and select the 500W Eurener bifacial panels, I would be:

£20,600 with Tesla PW3
£20,000 with Giv Energy All-in-One system.

Although this would maximise savings and even put me in a position where the system generates income, this is pretty high end and I would have to return to previous proposal I think due to initial financial outlay.

Screwdriva

I believe the latest quote has been deliberately inflated vs the original.

All 3 Installers I use will install (the maximum of) 26 Eurener 500W panels paired to the PW3 (with gateway 2) for between £15K -£17K installed in England. 

I would use this as a negotiation starting point with this installer and work backwards from there.

debitcardmayhem

The all in one came out in 2024 I believe, I remember it came out about 6-9 months after I had my system installed Dec 23.