Solar panels and battery - any real world recommendations?

Got a quote back for the near-equivalent Fox system to compare to the PW3:

21 x Hengdian Group DMEGC Magnetics 450 Watt Panels (DM450M10RT-54HBB)
1 x KH10 (Fox ESS)
3 x EP5 Integrated with Warming Function (Fox ESS)
Rails and mounting kits

£13,185.

(The PW3 quote was £15,409)
 
Found an error with my install which is 31 Aiko 470 neostar threes and two Tesla powerwall 3s with the gateway. As mentioned earlier in the thread the second powerwall is AC couple with three strings from the 31 panels going into the master powerwall. The array can generate 13-14.5kw in good sunlight and this is great on one Powerwall while its charging the DC batteries. Once the powerwall is full though the inverter can't deal with more that 12.5kw DC coming in and being inverted and sent to the grid. The inverter starts clipping so I loose power through the highest part of the day. Tesla say the PW3 can deal with upto 20KW of solar but it seems it can't when the batteries are charged. I need the installer back to put the 11 panel string onto the other PW3, he's currently in discussion with Tesla on it.
 
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Spleen Sauce said:
Got a quote back for the near-equivalent Fox system to compare to the PW3:

21 x Hengdian Group DMEGC Magnetics 450 Watt Panels (DM450M10RT-54HBB)
1 x KH10 (Fox ESS)
3 x EP5 Integrated with Warming Function (Fox ESS)
Rails and mounting kits

£13,185.

(The PW3 quote was £15,409)
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Curve ball, the fox set up with 2 ep11 batteries will probably come in cheaper than the power wall 3 quote also and have 30% more capacity but no whole home back up.
 
Dandle said:
Found an error with my install which is 31 Aiko 470 neostar threes and two Tesla powerwall 3s with the gateway. As mentioned earlier in the thread the second powerwall is AC couple with three strings from the 31 panels going into the master powerwall. The array can generate 13-14.5kw in good sunlight and this is great on one Powerwall while its charging the DC batteries. Once the powerwall is full though the inverter can't deal with more that 12.5kw DC coming in and being inverted and sent to the grid. The inverter starts clipping so I loose power through the highest part of the day. Tesla say the PW3 can deal with upto 20KW of solar but it seems it can't when the batteries are charged. I need the installer back to put the 11 panel string onto the other PW3, he's currently in discussion with Tesla on it.
Click to expand...

Makes perfect sense, its only got an 11.5kW inverter, so when the battery is full what's it supposed to do with the excess?? It can't send it to the batteries if they are full, and it can't invert it to 240v so only option is to clip. This should be obvious to an installer.

One way around it would be to export power so the battery isn't full at the highest time of the day, so the excess goes to the battery. Ultimately they need to put a string on the other PW3.
 
b0rn2sk8 said:
Curve ball, the fox set up with 2 ep11 batteries will probably come in cheaper than the power wall 3 quote also and have 30% more capacity but no whole home back up.
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Already asked them about that, for whatever reason the EP11 batteries aren't covered under the SolarTogether scheme so they're not discounted, brings the price to £15,955. So it's not far off.
 
Solar together is really just a lead generation scheme, and discounts are superficial and related to lead generation in reality.

Given how much prices have dropped recently, the prices you are being offered look inline with a lot of other quotes being posted on here, if a touch higher.

For context, my 23 panel system (split east/west) with a GivEnergy all in one and gateway was £16k 20 months ago. I’d expect to pay closer to £13k for these in the middle of 2025.

The RRP for the power wall 3 and the gateway is less than the RRP for my GivEnergy all in one without gateway at the time I bought it, the gateway was another £700 on top. My battery, like the old Powerwall 2 is AC coupled and also needs a separate string inverter so that’s another £600.
 
We're signed up to solar together and have a survey visit booked in a couple of weeks. The price we've been given is £3900 for 3 x Fox ess EP5 batteries, an fox AC1 G2 inverter (not sure on the size yet), and installation.
Our existing solar panels inverter is solaredge HD Wave (3.5kw), so I got some quotes for a solaredge battery, dc coupled 10 kW 400 v. Just the 10kw battery , installation, and sundries, three quotes from local reputable companies all came in at around £6k.

The £3.9k for the fox ess kit seems like a good price compared to the solaredge cost. Do you think it's worth me trying to get quotes from other installers for a similar system offered by solar together ?
 
Yes although £3.9k for a 15kwh ac coupled battery sounds about right. You could do it for less If you went down the Fogstar route but probably not that much less and you’d have to do all the donkey work.

Solar edge batteries always cost £lol.
 
Just had our first site survey from Little Green Solar who are local. Really impressed with the guy's knowledge and salesmanship. Our worry was adding panels to the roof and any possible loft conversion but turns out we can get 4 panels on our outbuilding and 4 on the kitchen extension, which should generate around 4k KwH pa (give or take). Battery would be from Sigenergy, forgot which panels but they were 450w a piece.

He was knowledgeable, explained things really well and not pushy at all with upsell. My wife and I have cast our votes on what the final quote figure will be :p.
 
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b0rn2sk8 said:
Yes although £3.9k for a 15kwh ac coupled battery sounds about right. You could do it for less If you went down the Fogstar route but probably not that much less and you’d have to do all the donkey work.

Solar edge batteries always cost £lol.
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Thanks. Assuming the survey all goes fine we'll go ahead with the fox ess system.

What would you say is a reasonable cost for adding whole house back up? Using a manual switch.
My understanding is that the fox ess inverter comes with EPS, which can provide wholehouse back up . We have quite a lot of power cuts where we are so think it'll be worth it.
 
It depends on how complex the install is.

It could range from £250 for a basic manual switchover on an easy install (e.g. inverter, and meter tails are accessible and roughly in the same location) to £lol.
 
The Fox has EPS but they do not yet do a gateway, so its a pain to set up. I've just gone through the same thing as I wanted to put my batteries in the garage and have a changeover switch. For me, it was too expensive and complicated as it would require a bigger consumer unit in the house as its full, another in the garage, cable runs from garage to house inside and out and then the changeover switch itself.

In the end, its too much cost and faff so Im changing the lot and going for a Sigenergy inverter, gateway and batteries. The Sig inverter is 12kw and I can connect up my EV charger, heat pump and other inverter. It gives me much more scope to get more battery storage too as my current Fox ones cannot be expanded much more and are not wearing well (90% SOH after 700 cycles!). Plus they are not heated (check this on any quote as the EP batteries come in heated and unheated versions).
 
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Admittedly I assumed the gateway feature was a standard/default. Do many in here have it? We've had 2 outages in 2 years, the site survey guy said we probably don't need it.
 
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I have it, but it's actually part of my inverter (Victron Quattro), I think we've had one power cut that I'm aware of since installation, and that lasted about two minutes.
 
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That’s not an uncommon assumption.

Mine has triggered once in 18 months and that only lasted a few minutes also.

A fully automatic gateway starts at about £1k installed.
 
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I didnt even consider it initially as we'd had one power cut in the first three years in the house. Now however, for whatever reason we get them regularly, sometimes several in a day.
 
I'll ask the engineer coming to do the survey what backup options are practical. I don't want to spend lots on it.
In our case, there's a spare slot on our consumer unit, 10 m of 60 mm ducting to run cables between the consumer unit and the new inverter. We regularly have power cuts , usually 6-12 per year , some only for a few seconds some for a few hours .
All our heating and cooking is electric , but running both the ASHP and the cooker at the same will probably draw too many watts.
 
Numbers are in.....

Proposed System
  • 3.6 kW solar array – 8 × SunPower Performance 7 (450 W) panels
  • Estimated annual generation: 2,639 kWh
  • Battery: Sigenergy SigenStor 8.0 kWh (usable 7.8kWh)
  • Estimated annual savings: £1,270
  • Lifetime bill savings: £76,336
  • Payback period: approx. 6 years 5 months
  • Bird protection: Included on the extension panels
  • Net system cost: £9,721
We used 3,700 kWh in our first year at a cost of £1,150 (Nov 23 - Nov 24). Our usage is a bit higher year on year comparison (Nov 24 - July 25). Mere minutes after this came through, another company rang (Skylar Solar - platinum partner of Sigenergy, whatever that means) and did their pitch. He said the 5/8 kWH batteries were previous gen and some are trying to clear out stock, they offer the latest gen of 6 and 10 kWH batteries. Also that, we're probably more suited to a 10 as our annual usage averaged across 365 days comes to about 10.1 kWh. They're going to send their quote through shortly.
 
doodah said:
Numbers are in.....

Proposed System
  • 3.6 kW solar array – 8 × SunPower Performance 7 (450 W) panels
  • Estimated annual generation: 2,639 kWh
  • Battery: Sigenergy SigenStor 8.0 kWh (usable 7.8kWh)
  • Estimated annual savings: £1,270
  • Lifetime bill savings: £76,336
  • Payback period: approx. 6 years 5 months
  • Bird protection: Included on the extension panels
  • Net system cost: £9,721
We used 3,700 kWh in our first year at a cost of £1,150 (Nov 23 - Nov 24). Our usage is a bit higher year on year comparison (Nov 24 - July 25). Mere minutes after this came through, another company rang (Skylar Solar - platinum partner of Sigenergy, whatever that means) and did their pitch. He said the 5/8 kWH batteries were previous gen and some are trying to clear out stock, they offer the latest gen of 6 and 10 kWH batteries. Also that, we're probably more suited to a 10 as our annual usage averaged across 365 days comes to about 10.1 kWh. They're going to send their quote through shortly.
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The Sigenergy 10.0 battery is actually a 9kWh battery with 8.76kW usable. The 6.0 and 10.0 are new though, but fully interchangeable with the 5 and 8s.

Which Sig inverter size are they putting in? The 8.0 battery can discharge at 4.0kW, so you'll ideally want the 5kW inverter to make best use of that.
 
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