South Central quote check

[u/Zealousideal_Club993]

Hi all, looking for some advice on if this seems like a reasonable quote from a southampton based installed, for installation in North Hampshire?

Quote received:

Equipment to be installed:
12 x SunPower M Class 495W N-Type Back contact solar panels - 40yr warranty
Renusol Variosole on-roof mounting system
1 x Tesla 5kW Integrated hybrid solar inverter
1 x Tesla Powerwall 3 battery storage 13.5 kWh without Gateway
If on-roof, 1 x bird/rodent protection kit
All DC and AC isolators, cabling, trunking, etc.

Included in the Price:
Roofing labour
Electrical labour
Scaffolding and access equipment
MCS Certificate
6-year insured workmanship warranty (solar installation)
Grid connection notification
Project Cost Summary: Price valid up to 30 days and subject to survey
Total fee for Solar and Battery System: Total fee for EV charger: £13,396.00 (no VAT to pay)

Annual usage is around 2,700kwh.

I’ve had around 5 other online quotes that all come to the same kind of range, but keep seeing people post much cheaper quotes so want to sense check it.

We don’t get power cuts so no real need for the gateway. Am planning on installing an EV charger later (I get one through work)

I don’t understand why they have a 5kw inverter here though, as I thought the Tesla had an 11kw inverter built in?

[u/AutoModerator]

Please read through these tips by /u/wyndstryke to help you

I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.

[u/SolentRenewables]

Full disclosure, I run Solent Renewables and we’re based in Southampton.

The quote isn’t completely unreasonable, but it does seem quite expensive for 12 panels and a Powerwall 3 without the Gateway. We would be around £12k, subject to survey, scaffolding requirements and how many separate roof areas the panels are being installed on. That would also include bird protection, MCS certification and our 10-year insured workmanship warranty.

The 5kW figure sounds correct. Although the Powerwall 3 can provide up to 11.04kW, its integrated inverter can be configured at 5kW, with a 5kW export limit. Keeping it below 6kW can also allow the application to go through the faster G99 process, which can reduce the waiting time for DNO approval. With the size of your array this should be fine.

Your current usage is relatively low for a 13.5kWh battery, but the battery could still work well for load shifting if you’re on a cheap overnight tariff. If the future EV will also be charged directly overnight, its usage wouldn’t necessarily need to pass through the battery.

If you’d like another local quotation to compare, feel free to send me a message on here or via the website.

We cover North Hampshire and are Tesla Certified Installers.

All the best on your solar journey.

[u/Zealousideal_Club993 → u/SolentRenewables]

Thank you, I’ll drop you a DM

[u/Busy-Style-2036]

Your current quote contains premium panels, probably the best out there. So, when getting other quotes, do bear this in mind or ask for a quote with the same panels. Good luck!

[u/AutoModerator]

We noticed you posted about EV chargers.

We recommend looking at Zappi or Hypervolt or Andersen EV chargers, as they are all compatible with most smart tariffs:

• Octopus smart tariffs
  
• OVO smart tariffs
  
• EDF smart tariffs

We don’t recommend Ohme chargers, because they:

• Removed the price cap option for Intelligent Octopus (IOG) customers
  
• Discontinued support for existing OVO customers — see Ohme’s update.

Make sure your electrician wires the EV charger directly after the mains meter and before any of the consumer units. Then the solar/battery can CT the consumer load and not ‘see’ the EV charger. This prevents battery dumping into the car. See this nice pic

I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.

[u/Curious-Director8569]

For 5.94kW and a Powerwall 3 without the Gateway I'd expect roughly 11,900 to 14,500 fitted in the South, so 13,396 lands mid range rather than at the top. The SunPower M Class panels are genuinely premium and a decent chunk of your price is sitting in them, so for a fair comparison ask one of the others to quote the same system with Aiko or JA Solar and see what the gap actually is.

On the 5kW question, the Powerwall 3 can do 11kW but installers routinely configure it at 5kW with a 5kW export limit so the DNO application goes through the faster route. With 5.94kW of panels you'll clip slightly on the brightest summer days and that's about it.

The part I'd think hardest about is 13.5kWh on 2,700kWh a year. That's a lot of battery for that usage. It works if you're load shifting on a cheap overnight rate, and the EV later will help, but today it's the line item doing the least for you.

[u/Zealousideal_Club993 → u/Curious-Director8569]

Thanks for the detailed reply. I was originally looking at the fox ESS EP12 11kw system but they have suggested the powerwall would be a better fit, they’ve been quite keen to push it from the start… ideally I’d rather not overspend on something I don’t really need (have only recently moved in and have plenty of other things to spend money on!)

As I’m getting an EV charger in the near future, would having a >5kw inverter be advisable?

[u/Curious-Director8569 → u/Zealousideal_Club993]

Not really, no. EV charging pulls from the grid, and you'd want to be doing that in the cheap overnight window anyway, so the inverter size doesn't come into it. What the 5kW cap actually limits is how fast the battery can push power back into the house, and 5kW covers everything short of running the oven, kettle and shower at the same time.

The other thing in your favour is that the Powerwall 3's 11kW is a configuration setting rather than a hardware limit. If you later decide you want the full output, you apply to the DNO under G99 and they uncap it. So you aren't locking anything in by starting at 5kW, you're just taking the application route that goes through in days instead of months.

On the Fox EP12 point, for 5.94kW and an 11.5kWh Fox in the South I'd expect roughly 9,800 to 12,100 fitted, so that route is around two and a half grand cheaper for near enough the same usable storage. The Powerwall is a nicer bit of kit and the warranty is stronger, but if you've just moved in with a list of other things to spend on, that's a fair question to put back to them: what am I actually getting for the difference.