Solar Together

[DrFfybes]

This scheme gets offered on a fairly regular basis, and I think for many it's a good deal and worth doing.

Personally for me I ran the numbers and it didn't make as much sense, as our household only uses about 2500 kWH of electric/year, so the payoff time would be fairly long.

our household uses about 2500 kWh per year, plus another 1500kWh to charge the EV. But anyway, I charge the EV at night, so not affected by the solar output.

There are 2 savings from solar: offsetting peak time usage in the home, and exporting to the grid.
[...]
With this kind of split, I am on course to pay back the solar installation in less than 8 years.

FD

Exactly this - the financial return largely depends on your tariff and export rates. The best at circa 15p (and 23p between 4-7pm on a flexi tariff) make the payback times much shorter. So far this year our export of surplus has exceeded our import so we've been a net exporter since late March. Our average income per unit exported has been 18p in the last year according to the Octopus bill for 2.35 MWh so £423 income from surplus on about £7k of panels, plus 1.8MWh we used at 25p so another £450 there. Payback time, erm, well about 8 years

Of course it is not so simple, we also have batteries that can charge overnight at 15p so effectively our import cost is only 15p which actually reduces the effective income from the panels for consumed power and increases the payback time. The corollary to this is that in winter when we generate little we save 40% on our actual electric bills. We could also set the battery to discharge in the evening peak at 25p and then recharge later at 15p, but we'd need to keep enough charge to last us the evening so this would probably only make us 60p/day and then only on the sunny days the battery was topped up from the sun,so perhaps another £100pa if I could be bothered faffing about.

Paul

[the0ni0nking]

I have been in communication with the proposed installer discussing my requirements and so thought it worthy of an update.

The proposal now stands at:
8 x JA Solar 405w JAM54S31 panels on one roof
8 x JA Solar 405w JAM54S31 panels on the other roof
Module level PV optimisers x 16
Emlite 1-Ph Bi-Directional Generation Meter
Bird Mesh
Fox ESS Hybrid H1 Inverter 6.0kW
Fox ESS EP 11 - 10.36kWh battery storage
Sub Distribution Board
Bespoke Scaffolding

My googling:
16 panels cost £74.40 each = c£1,200
Guestimate of fixtures/fittings = c£1,200 (i.e same cost as the panels themself)
Optimiser x 16 @ c£40/each = c£640
Meter = negligible c£50
Inverter = c£750
Battery = c£2,400
Scaffolding = c£1,100
Labour etc = ?

https://www.theheatpumpwarehouse.co.uk/ ... -mr-black/
https://theecosupermarket.co.uk/product ... optimiser/
https://www.tradesparky.com/solarsparky ... verter-6kw
https://theecosupermarket.co.uk/product ... h-battery/

Not disclosing the price as a bit of a game for those with more knowledge but what would seem reasonable for the above. As a guide, it's still below 5 figures although not by much. Although the savings estimated by fitting the system have also gone up too.

If anyone really wants to see the full quotation, I'm happy to email it to them as appreciate all the data isn't likely included in the above (as the quotation includes a raft of other info too).

[DrFfybes]

Thank you for updating this. A few observations...

The fixings for our £80 Eurener panels far exceeded the cost of the panels themselves. 8 panels installed on a South facing roof were over £2k and scaffold was already there. We thought this was expensive until we started adding up the cost of the bracketry.

The clamp meter for sensing the in/out current at the consumer unit tends to be circa £70.

Your battery cost does not appear to include the battery management system, another couple of hundred quid.

A roll of 10mm2 cable to run from the system to the consumer unit could be another £100.

The Fox stuff is very cheap compared to (say) Huawei or Givenergy, but a similar system with the Huawei stuff 2 years ago would have cost us circa £15k + scaffolding (batteries were circa £7k alone then, now nearer £4k for 10kWh of Huawei).

Installation will probably be 4 person days, but as to the price??

Not disclosing the price as a bit of a game for those with more knowledge but what would seem reasonable for the above.

Well on 14 Aug you said

Seems very cheap to me - if I double up the cost of scaffolding (as that is split out separately) to assume both sides of the house and increase the panels up to 20, the revised price comes to £8,755.

So with 16 panels I'm going to guess at about £9k

Paul

[the0ni0nking]

Well on 14 Aug you said

Seems very cheap to me - if I double up the cost of scaffolding (as that is split out separately) to assume both sides of the house and increase the panels up to 20, the revised price comes to £8,755.

So with 16 panels I'm going to guess at about £9k
Paul

Damn you pesky posting history

That quote excluded bird meshing and had IIRC a 3.6kW inverter which is now 6kw - I think this means therefore they're having to apply for the DNO in advance rather than retrospect.

So the quote is actually £9,835. (Worth adding that one side will require 3 storeys of scaffold and one side just 2. I think I've mentioned it before but that's the wonderful nature of the house been on a hill!).

[DrFfybes]

Although the savings estimated by fitting the system have also gone up too.

I missed this before, however I raised this with our installer when we had the extra panels added in June as out output for 12 months from the existing panels was a chunk down on the model. Apparently the models use a whole set of criteria to ensure accuracy, although none of them are particularly applicable to our installation and he basically said "well, you save more if it is sunnier".

For instance last October we generated 130kWh, the same panels for this month have generated 155kWh so far. August 2024 was also slightly up on 2023, but Sept 2024 output was only 211 compared to 275 last year.

Paul.

[TUK020]

In early August, I signed up to "Surrey Solar Together" - a bulk purchase deal organised by Surrey County Council, and paid my £150 deposit, and got an indicative quote by mail. Guy came to see me about a week later, agreed details, confirmed the quote and scheduled the installation/scaffolding etc for about 10 days later.

What I got:
12 panels each of 400W nominal peak = 4.8kW
Wire mesh around panels to prevent birds nesting/squirrels etc (this was a highly recommended extra)
12 optimisers (chimney in the middle provides variable shading during the day)
3.7kW inverter (the thing that converts AD/DC and vice versa)
9.6kWh battery (double size than standard at my request). These don't give full capacity - they discharge to a minimum of 10% power.
Solar boost (generated power goes to serving domestic consumption first, charging battery second, boosting the immersion heater third, and only exporting to the grid fourth)
Control panel and logging
Scaffolding (3 story house) & Installation

Price: £9500:

Installation experience:
Scaffolding went in without problem
Electrician turned up on appointed day and did all of the electrical stuff without problems (routing of cabling from panels to battery/inverter was quite tricky, but they did a good job). Roofer was ill that day but turned up the following day and did all the panels then.
They left the scaffolding up for another 10 days to ensure there were no problems - this was a bit of a pain.
Overall, installation was very good - minor but infuriating issue was the mess up of the house WiFi. I had been worried about range from the study WiFi at the opposite end of the house to the garage, so the electrician put in a WiFi booster which then turned out to mess up the 2.4GHz band of the dual band WiFi. I would up redoing my WiFi later with a mesh system, and so got rid of this.
Second irritation was finding 3 nails left on the drive - could have been an unnecessary puncture.
Overall the install was good. Got the electrician to talk me through exactly what he had done on wiring & system installation, and he clearly knew his stuff.

Other relevant info:
I have an EV, and a home EV charger point already installed
I have an Octopus tariff designed for EV users - 25p/kWh standard rate, and 8p/kWh cheap rate between the hours of 00.30-05.30.
Because of this tariff, my export rate to the grid with Octopus is limited to my cheap rate - 8p.
Large house, multiple occupants, dishwasher and washing machine run a lot. Big electricity user.
Heating and hot water is from gas boiler, except for immersion heater top up described above.

Set up:
I have a Growatt dashboard (the make of inverter) on line, and programmed the system so that the battery charges from the mains overnight at cheap rate (also when I am charging my car), and then the house runs from battery during the day. The battery discharges until the solar panels start generating (which then runs the house and recharges the batteries a bit) and then discharges again during the evening.
Installation faces south west. Solar generates between 09.30-04.30 (GMT) can be very variable according to cloud level.

Usage/generation 20/8-7/11:
Domestic consumption approx 2MWh over about 10 weeks.
Solar generation: 680kWh
Battery charge/discharge: 660kWh
Exported to grid: 148kWh
There is some overlap between the generation and discharge figures.
Very roughly - 1/3 of my electricity is solar generated (free marginal cost). 1/3 is electricity is bought at cheap rate, and used at expensive rate. The remainder is either charging the car at cheap rate, or using grid day/evening at standard rate.

Conclusions
Too early to tell is the models on which I based by 5.75 yr payback are correct - really need to see an annual solar generation figure.
The other thing is that these models are very sensitive to Electricity usage (this will probably reduce as kids leave home), and electricity prices (don't foresee these coming down much), and the continuation of off peak cheap rate tariffs (fairly safe bet given the peak to average demand patterns of the UK.
An early thought is that the payback from the batteries probably exceeds that of the panels - although this largely assumes you have forked out for the inverter as part of the panels.
This then leads to an interesting thought that the long term profitability of this set up will to some extent depend on the charge/dischgarge lifetime of the batteries (I pretty much fully discharge these every day)

So far so good

[DrFfybes]

12 panels each of 400W nominal peak = 4.8kW
[...]
Solar boost (generated power goes to serving domestic consumption first, charging battery second, boosting the immersion heater third, and only exporting to the grid fourth)
[...]
Large house, multiple occupants, dishwasher and washing machine run a lot. Big electricity user.
H
[...]
Domestic consumption approx 2MWh over about 10 weeks.
Solar generation: 680kWh
Battery charge/discharge: 660kWh
Exported to grid: 148kWh

Sounds good, I assume the "Domestic Consumption" includes charging your car, otherwise that is a heck of a high use.

I didn't bother with iboost/solar boost, it was about £300 extra and TBH it matters not to me whether I stored excess power in the battery first or the hot water, so spent £40 on a timer for the hot water and heat it overnight at the cheap rate.

You must have had better weather than us - I've generated 700kWh in the last 6 weeks from 8.4 kW of panels, although that includes this month which has generated pretty much nothing, although I'm not entirely convinced the App totals up the output properly.

Paul

[the0ni0nking]

In early August, I signed up to "Surrey Solar Together" - a bulk purchase deal organised by Surrey County Council, and paid my £150 deposit, and got an indicative quote by mail. Guy came to see me about a week later, agreed details, confirmed the quote and scheduled the installation/scaffolding etc for about 10 days later.

What I got:
12 panels each of 400W nominal peak = 4.8kW
Wire mesh around panels to prevent birds nesting/squirrels etc (this was a highly recommended extra)
12 optimisers (chimney in the middle provides variable shading during the day)
3.7kW inverter (the thing that converts AD/DC and vice versa)
9.6kWh battery (double size than standard at my request). These don't give full capacity - they discharge to a minimum of 10% power.
Solar boost (generated power goes to serving domestic consumption first, charging battery second, boosting the immersion heater third, and only exporting to the grid fourth)
Control panel and logging
Scaffolding (3 story house) & Installation

Price: £9500:

Installation experience:
Scaffolding went in without problem
Electrician turned up on appointed day and did all of the electrical stuff without problems (routing of cabling from panels to battery/inverter was quite tricky, but they did a good job). Roofer was ill that day but turned up the following day and did all the panels then.
They left the scaffolding up for another 10 days to ensure there were no problems - this was a bit of a pain.
Overall, installation was very good - minor but infuriating issue was the mess up of the house WiFi. I had been worried about range from the study WiFi at the opposite end of the house to the garage, so the electrician put in a WiFi booster which then turned out to mess up the 2.4GHz band of the dual band WiFi. I would up redoing my WiFi later with a mesh system, and so got rid of this.
Second irritation was finding 3 nails left on the drive - could have been an unnecessary puncture.
Overall the install was good. Got the electrician to talk me through exactly what he had done on wiring & system installation, and he clearly knew his stuff.

Other relevant info:
I have an EV, and a home EV charger point already installed
I have an Octopus tariff designed for EV users - 25p/kWh standard rate, and 8p/kWh cheap rate between the hours of 00.30-05.30.
Because of this tariff, my export rate to the grid with Octopus is limited to my cheap rate - 8p.
Large house, multiple occupants, dishwasher and washing machine run a lot. Big electricity user.
Heating and hot water is from gas boiler, except for immersion heater top up described above.

Set up:
I have a Growatt dashboard (the make of inverter) on line, and programmed the system so that the battery charges from the mains overnight at cheap rate (also when I am charging my car), and then the house runs from battery during the day. The battery discharges until the solar panels start generating (which then runs the house and recharges the batteries a bit) and then discharges again during the evening.
Installation faces south west. Solar generates between 09.30-04.30 (GMT) can be very variable according to cloud level.

Usage/generation 20/8-7/11:
Domestic consumption approx 2MWh over about 10 weeks.
Solar generation: 680kWh
Battery charge/discharge: 660kWh
Exported to grid: 148kWh
There is some overlap between the generation and discharge figures.
Very roughly - 1/3 of my electricity is solar generated (free marginal cost). 1/3 is electricity is bought at cheap rate, and used at expensive rate. The remainder is either charging the car at cheap rate, or using grid day/evening at standard rate.

Conclusions
Too early to tell is the models on which I based by 5.75 yr payback are correct - really need to see an annual solar generation figure.
The other thing is that these models are very sensitive to Electricity usage (this will probably reduce as kids leave home), and electricity prices (don't foresee these coming down much), and the continuation of off peak cheap rate tariffs (fairly safe bet given the peak to average demand patterns of the UK.
An early thought is that the payback from the batteries probably exceeds that of the panels - although this largely assumes you have forked out for the inverter as part of the panels.
This then leads to an interesting thought that the long term profitability of this set up will to some extent depend on the charge/dischgarge lifetime of the batteries (I pretty much fully discharge these every day)

So far so good

Thanks for this - I suspect my end price will end up similar - I'll have slightly more panels (16 v 14), similar battery size, a larger inverter, optimisers and bird mesh etc.

My scaffolding requirement will be 3 storey on one side and 2 storey on the other. Given there is no car in the property, having scaffolding sitting there for a while before/after installation taking up drive space and blocking access to the garage is really not an issue.

When I submitted the forms, I used my actual electric usage for the last 12 months and it was c5000kwH. The gas usage (CH) has dropped dramatically partly because the hot water on that property is coming from electric rather than gas.

My "site visit" is scheduled for the 3rd December which is when I am back in the UK so will report back after that with the final quote etc and I will also then become even more of a statistical obsessive than Paul when it comes to reviewing the data even though I don't live there anymore!

Some might ask why am I bothering doing the install given I don't live there anymore - and it's mainly purely selfish. I suspect 2 things - one the property will likely command more rental but I'm also sitting on GBP that takes me into higher rate tax on savings so little point keeping it in cash when I can't contribute to an ISA anymore (non UK resident), have already maxed out premium bonds, and have cash in EUR that is also paying interest albeit at a lower rate than GBP and is still deemed taxable in the UK which takes me over the savings allowance as to how/where it's held.

[flyer61]

Late to this party but I had my survey completed today. The Company is Grant Store and it is through the Solar Together scheme.

Not doing the main house but just the 2008 extension. 10 panels, when I have the full spec I will post it. But will involve car charging point and a largish battery.

I'm doing this for a couple of reasons. I want to try and get my house to an EPC of B. It is big and costs a bit to run. Combine this with trying to be as independent as possible from the UK grid. If I can achieve this i'll be happy. Cost is not the overarching issue.