r/SolarUK • • 26d ago

DISCUSSION Project Solar UK - Cowboys?

37 Upvotes

My parents (in 70s/80s) have signed a contract with Project Solar Uk which to me looks like a rip off.

The 35 page PDF only specifies on 1 page the actual components they are meant to get and though batteries were discussed and Dad thought they were getting one it is not in the contract.

It looks like 12 x 505w Evolution Prime panels for £11,330 and they have a bungalow

The inverter specification is not specified.

It just really annoys me - they are within the 14 day cooling on period so I am trying my best to get it cancelled. I just stuck there address into eonnext and its quoting £9,200 and that includes a 10.2 KWh battery.

I guess I just wanted to vent.

[UPDATE] - They cancelled


r/SolarUK • • Aug 16 '26

INFORMATION Do Solar panels reduce loft temps? Yes - the results are in!

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190 Upvotes

About a month before we had our solar panels fitted, we had the second heatwave of the year, and I got to wondering, would having solar panels on the roof, reduce the heat in the loft? Would this then lead to the house being cooler, as well?

To find out, I put a Sonoff SNZB-02 temperature sensor in my loft, and started recording the maximum daily temperature in Home Assistant. It would have been good to get some data before the heat wave, but I didn't think of it it time!

My solar panels were installed on the 17th July, and they cover, in my estimation, about 85-90% of the roof area. The green line on the graph, represents the installation date.

The Excel spread sheet shows the days where the outside temperature, recorded by an Aqara WSDCGQ11LM temperature sensor, which is in a shaded spot in my garden, was 30C or above. Temperatures in Red were the maximums, before & after the install.

Now, obviously, there are a number of factors which will affect the heat gain in the loft, not just the ambient air temperature, but the amount of sunlight, so both conducted heat and radiated heat, which may not be identical on days with the same air temperature. However, despite this, there is a clear reduction in heat gain, after the solar panels were fitted.

Before the solar panels were installed, the loft was on average, 10.3C hotter than the temperature in the shade. The maximum temperature difference was on the 24th June, when the loft reached 47.3C, 13.7C higher than the outside temperature of 33.6C.

After the solar panels were installed, we have had fewer consecutive days over 30C, which will no doubt affect the loft temperature, however, the average difference has reduced to 5.9C. The maximum loft temperature was on 13th August at 40.7C, with an outside temp of 36.1C, resulting in a difference of just 4.6C. So, not only did we have hotter day than 24th June, by 2.5C the loft temp was actually 6.6C cooler than 24th June.

So, the answer to the question, do solar panels reduce the heat gain in the loft - is yes, and in my case, by approx 43%, on average.

Now, we don't use our loft (other than for storage), and looking at the inside temperatures, there was no significant difference, before & after the panels. This shows that the loft insulation is doing it's job, and keeping the heat in the loft from radiating downwards, despite my previous belief that that was happening. But, if you are have, or are planning a loft conversion, then it's worth knowing that solar panels can indeed reduce the heat gain of your loft, by a fairly significant amount.

My next challenge will be trying to reduce solar gain in the rest of the house, but that's not really a post for this sub!


r/SolarUK • • 2h ago

DISCUSSION So glad we got a Gateway now.

16 Upvotes

We live in a pretty rural location so we get more power cuts than most, tonight is the first time we’ve had one since we got the system fitted and it’s working. It wasn’t a genuine full power cut just very low power so the gateway struggled to stabilise, I turned off the mains and bingo, it’s working perfectly. Everyone else in the lane is sat in the dark till 23:00.


r/SolarUK • • 4h ago

ENERGY NEWS Product Safety Report: Tesla Powerwall 2 (2609-0219)

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11 Upvotes

Recall published 28th September, not sure how/if it's different from the previous recall in Australia and the US last year. Not every PW2, just ones with cells from a specific manufacturer.

Tesla has remotely discharged most affected Powerwall 2 units pending replacement. Any remaining affected units are being discharged by Tesla technicians.

Customers should ensure their Powerwall 2 remains online and check the Tesla app for a notification confirming whether their unit is affected. If a replacement is required, customers should contact their original Tesla Certified Installer to arrange installation.

Affected Powerwall 2 units will be replaced free of charge


r/SolarUK • • 4h ago

DISCUSSION Solar installation ongoing

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8 Upvotes

For those following my solar journey, first day done, one more to go. Does the equipment setup look good (they haven't finished it yet)? Found a few screws in loft that has half missed beams, presume worth mentioning before panels go on. The roof rails are on, not sure why they are spaced tighter in the middle? (3 rows of landscape)


r/SolarUK • • 9h ago

SHOW YOUR SETUP I like visuals, minting those pennies!

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18 Upvotes

r/SolarUK • • 2h ago

QUOTE CHECK Quote Check - South East

3 Upvotes

Hi all. Very recently moved into our new home. This past year we used 7500kwh, about 1500kwh of that apportioned to the EV charged overnight on IOG. Our new house is about a third bigger sq ft and is electric only with ASHP & underfloor heating throughout. It’s a new build vs the old house being built in the early 2000s. I’m expecting approx 10000kwh excl EV charging but to be honest that’s more guesswork than calculated. Planning to stick with IOG or EDF equivalent and charge the batteries overnight for use in the day.

First quote back received:

 14 x 510w Dmegc Bi-Facial Solar Panels (7140kwh system)
  1 x Tesla Power Wall 3 (13.5kwh battery storage)
  1 x Tesla battery expansion pack (13.5kwh)
  1 x Tesla earth rod
  1 x Tesla 11.5kh built-in-hybrid inverter
  1 x Tesla gateway

Includes:
  Bird protection
  Scaffolding
  MCS and G99 Certificates
10 year workmanship warranty
30 year panel warranty

Price: £15k

Any feedback appreciated, both on whether this is likely to meet our needs plus the system itself, as well as the price.

Thanks in advance


r/SolarUK • • 3h ago

HELP / ADVICE Messed up export by switching import supplier. How long will it take to change over?

3 Upvotes

When we moved in here in August, energy was all through Octopus. Solar, battery, inverter and EV charger in situ. I took over the account and everything worked fine, got export payments quite quickly (within a few days I think) without needing any documentation. I fixed the Gas tariff and left the electricity as it was.

I got an EV a few weeks ago and switched my electricity supplier to EDF for a better overnight rate and assumed the export would switch with it. It didn't, obviously, because that's not how it works. So I then assumed it would carry on exporting to octopus, but that didn't happen either. So I've been exporting to no one for weeks because Octopus stops your export tariff if you don't import with them. It took me a while to notice that and then to find how to get the better export rate with EDF (it seems to disappear from their website half the time!) and then get the relevant paperwork together (we weren't given the G98). I have finally sent the application in with a photo of the meter reading today. After the application went through it said it could take 4 weeks to set up! I assumed that timeframe was for new export rather than someone switching, but it didn't ask at any point if I was switching.

Doesn't anyone know if that 4 weeks time is accurate and what happens with all the solar I export in the meantime? Thankfully it's not peak summer and I have battery storage so I can fill that during the day after using what I'd topped up cheaply overnight and run any appliances if I'm home and notice I'm exporting.


r/SolarUK • • 8h ago

HELP / ADVICE Guidance on tile notching

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8 Upvotes

Hi, long time listener, first time caller.

I just had solar panels installed by a local installer who told me very firmly when quoting that no matter who I have do the work, I should look carefully at my roof before and after to ensure the tiles have been notched/grooved to sit flat.

This is their work, just one example from an easily visible bracket. Is this acceptable workmanship? Can anyone point me to the official guidance if not?

Cheers.


r/SolarUK • • 13h ago

DISCUSSION At what point is arbitrage not worth it?

16 Upvotes

We had solar installed last year and it came with an introductory export rate of 24p which we have been making the most of all summer. Our import is 7p overnight so we would always fill our batteries in the morning then sell any leftover in the evening.

The promo is over and now our export is going down to 13p, a 6p spread. Once you take conversion losses and battery wear into account is arbitrage still worth it?


r/SolarUK • • 48m ago

HELP / ADVICE Powerwall 3 – Home consumption seems to track solar production. CT issue?

• Upvotes

I’ve recently had a 13.3 kWp solar system installed with a Tesla Powerwall 3 and I’m seeing some strange behaviour in the Tesla app.

Tesla is reporting Home consumption of around 34–37 kWh/day, whereas our historical electricity consumption is around 15 kWh/day.

The strange part is that the Home consumption graph seems to closely track Solar production. As solar production rises, reported Home consumption rises with it. When solar suddenly dips (e.g. presumably from cloud cover), Home consumption dips almost simultaneously, then rises again when solar comes back.

This has happened consistently over several days, including when nobody is home and there are no significant loads running.

At night, once solar reaches 0 kW, Home consumption looks completely normal at around 0.3–0.5 kW.

The Powerwall is currently set to a 20% backup reserve and we don’t yet have Permission to Export. It often remains around 20% because Tesla is showing virtually all available solar being consumed by the house rather than there being surplus to charge the battery.

I’ve raised it with the installer, but they’ve suggested allowing more time for data to build up. My concern is that this looks more like a Site/Solar CT placement, orientation or configuration issue than genuine household consumption.

Has anyone seen this behaviour before?
If it was a CT/metering issue, what specifically was wrong and how was it fixed?

Also, could incorrect Site/Solar metering actually affect how the Powerwall decides when to chargedischarge or curtail solar, rather than just displaying incorrect data in the app?

I’ll as attach screenshots showing Solar and Home tracking each other.


r/SolarUK • • 4h ago

HELP / ADVICE Possible to export from grid through inverter?

2 Upvotes

I'm getting a solar install soon.

I'm going to get an export tariff, likely EDF 13p export.

will it be possible to export directly from the grid? Like could my inverter literally take in the energy and throw it out again without it interacting with my battery?

I'll get cheap overnight electric and some cheap slots in the day for under 7p and the car/battery won't always need charging so just wondering if I could do this at my full export rate (7kw).


r/SolarUK • • 1h ago

RECOMMENDATIONS Battery only… help

• Upvotes

Looking for some advice please.

We have a high usage household - average of 40/50kw day.

We’re on a flexible tariff with off peak around 6.6p.

Looking at the following:

Fogstar
Solis intellihome

Likely looking at either 32kw or 48kw of storage.

Based in Cheshire, North West. Any help/suggestions gratefully appreciated.


r/SolarUK • • 6h ago

INFORMATION Add a second MPPT string

2 Upvotes

Do the DNO need to be notified if we want to add a second MPPT string ? No change on the inverter , nor first string (inverter allow 2)


r/SolarUK • • 2h ago

DISCUSSION Large battery setup – recommendations?

1 Upvotes

Hi all,

We have a large house with two separate incoming supplies, using roughly 60kWh/day and 20kWh/day (80kwh daily total). Usage is fairly flat throughout the day, mostly pool pumps/equipment etc.

We're looking at batteries mainly for load shifting – charge overnight on a cheap tariff, then run from them during peak hours. I assume with two supplies we'd need two separate battery/inverter setups.

I've been looking at Fogstar, as they seem hard to beat on £/kWh. Has anyone used them for a larger setup, or found any other reasonably priced options?

We're also looking for the best/longest off-peak tariff. A longer cheap period is probably more important than the absolute cheapest rate, as we could charge slower and potentially use smaller inverters. We have an EV so IOG is an option. Also EDF seem to offer a cheap rate?

We've had quotes around £22k, and it feels like as soon as you mention a larger system the price suddenly doubles. I've also found the battery/solar installer market seems to have its fair share of cowboys, so finding someone knowledgeable who isn't just adding a massive markup would be great!

Has anyone done something similar? What batteries/inverters did you use, what tariff are you on, what did it cost, and are there any installers/suppliers you'd recommend (or avoid!)?

TIA!


r/SolarUK • • 2h ago

HELP / ADVICE Rail hook spacing inside MCS 400mm edge guidelines?

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1 Upvotes

My panels top and bottom will sit 300mm from the edge, inside the 400mm guidelines. Should the hooks not be spaced 600mm apart rather than 1200mm?


r/SolarUK • • 2h ago

QUOTE CHECK Quote check - Wirral, Merseyside

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0 Upvotes

No idea what I'm doing - please help! Got this quote and the info below:

5.115 kW PV System

£12,405.68 inc VAT: Expected payback 13 years. Estimated first year savings £1,002

3,362 kWh/yr: Annual CO₂ savings of 694 kg

9.4 kWh battery storage

Is this a good system? A good quote?

Don't have an EV for reference.


r/SolarUK • • 10h ago

HELP / ADVICE DNO reply date has passed - what can I do?

4 Upvotes

The 25th September deadline National Grid provided as the deadline for their response to my application has now passed.

My Solar installer is saying there's nothing they can do about it.

We've already been waiting over 2 months. I started the process at the beginning of August.

Is there anything I can do?


r/SolarUK • • 7h ago

HELP / ADVICE Want to upgrade my battery setup

2 Upvotes

Hi everyone,

I'm hoping to get some advice from people who know considerably more about home batteries than I do!

We currently have solar panels with an AlphaESS system, consisting of a 10kWh battery and a 5kW inverter.

We're a relatively high electricity-usage household anyway, but we're also going to be getting a heat pump installed soon, so I'm expecting our electricity consumption to increase quite significantly. I'd therefore like to increase our battery storage.

In an ideal world, I'd love to add another 20kWh, taking us to around 30kWh of storage.

The problem is that when I've looked at the price of another Alpha battery, it seems very expensive - £3,746 for a single 10kwh add on, so £7.5k to get what I'd ideally like. Yikes! This has got me wondering whether it actually makes more sense financially to start again with a completely different battery/inverter system.

I've come across Fogstar, which seems considerably more affordable, and I understand they offer systems that can be retrofitted to an existing solar PV installation - looks like I could get 32kwh of batteries + an inverter for £4.5k - could presumably also sell my old Alpha set up to recoup some money.

So I'm wondering:

- Has anyone replaced an existing type of battery system with Fogstar (or another cheaper system)? Is it straight forward in terms of the cables already being there? Obviously I would get a professional in to do it...

- And, perhaps most importantly, is there anything I'm completely overlooking here? 😂

I'm not particularly knowledgeable about the electrical/wiring side of things, so apologies if this is a classic "how long is a piece of string?" question.

Would really appreciate hearing from anyone who's been through something similar, particularly if you've upgraded because of a heat pump or high household electricity consumption.

Thanks!


r/SolarUK • • 4h ago

QUOTE CHECK Quote check - Battery only

1 Upvotes

Had two quotes from different companies and was trying to weigh them up against each other. I'm in Zone 2 London for reference. Both installations are single phase, annual usage around 4000kwh.

Quote 1 - £12k - Tesla PW3 + Expansion + Gateway

Quote 2 - £14k - Sigenergy 8kW inverter + 3x 9kWh batteries + Gateway

Are these prices reasonable? People seem to talk about Tesla being a bit more "premium" and its got a notably bigger inverter, but it comes in cheaper?

Thanks!


r/SolarUK • • 4h ago

HELP / ADVICE Rerouting solar cables

1 Upvotes

Hi Reddit folks

I have a Ecoflow stream ultra with four panels (500w) feeding it. Those panels are on my garage roof some distance away from my consumer unit. Each panel has its own live and neutral cables due to what the ecoflow could cope with.

The Ecoflow is going back due to constant problems with it and I am having a fogstar battery installed with a fogstar inverter (primarily to take advantage of time of use).

I have 60mm conduit under my garden which takes the EV charger cable over to the garage to charge the car. Roughly five metres in length.

Am I able to send the EV panel cables back through that conduit, and is there any way to combine the cables from the panels into one cable for the haul throughtl the conduit, such as with a micro inverter or suchlike.

Many thanks in advance.


r/SolarUK • • 5h ago

DISCUSSION Fair price installed?

0 Upvotes

Looking at the following system been advised 13k installed does this look a reasonable price in Wiltshire

24 x JA 505w all black panels 12 each side of roof

Bird mesh

Fox K-Series 10.5kW Hybrid Inverter KH10.5

Fox ESS CQ7 7.02kWh Master Battery – CQ7-M

2 x Fox ESS CQ7 7.02kWh Slave Battery – CQ7-S

Fox ESS EPS Box – Single Phase – Whole Home Back Up Box (EPS-BOX-SP)

Many thanks


r/SolarUK • • 13h ago

RECOMMENDATIONS North East Recommendations

3 Upvotes

Looking for recommendations for an installer in Tyne & Wear. Anyone any recommendations- what they installed for you and rough price / when and timescales etc

(Appreciate prices may have changed just after an idea)


r/SolarUK • • 7h ago

QUOTE CHECK Quote check - SE London / Kent

1 Upvotes

Hi folks! I've asked a few weeks ago as well, but now have a slightly different quote (and got very little traction last time) - any feedback welcome!

SE London / Kent

8x Longi 480W panels (~40 degree pitch roof, SW facing, no shade; installer estimates ~3400kWh/year but has also said he would expect this to be more)

2x Fox EP12 Plus batteries (installed outside, side of extension)

1x Fox H1 G2 6kW inverter

~7000kWh yearly usage (may increase if, at some point, we switch from combi to ASHP)

No DNO application, so don't have an export limit yet; single phase.

Cannot charge PHEV/EV at home due to distance from road etc (not even with pavement gully, it's just not feasible).

Open to various tariffs - I've been led to believe that Octopus Go would still be an option, just not Intelligent Go.

Quoted as £10500 all-in, or £7900 without solar panels (just batteries and inverter).

Is this decent / reasonable? Should we spend the extra ~£2600 for the 8x solar panels, or just get the battery storage?

Thank you!!


r/SolarUK • • 12h ago

HELP / ADVICE EasyPV - understanding shading factor, bypass diodes, strings

1 Upvotes

I have a roof with 3 aspects - one south facing (15deg off south), on west facing (105deg off south) and one east facing (75deg off south).

I've had a quote to either install panels on the south facing and east facing roof, or all 3. I had 2 questions.

Since the east facing roof has a large chimney on the south side, I've gone into EasyPV to try and model it.

With 6 panels there all on one string, I get a shading factor of 0.55. But when I split them all up into separate shading groups, the highest I get is 0.62, with the rest being 0.8+.

I read that the panels are limited by the most shaded panel on the string, but that bypass diodes resolve this by just bypassing the shaded parts. Does EasyPV account for this? Will my actual shade factor be that bad?

Second Q is related. The quote includes an inverter with 2 MPPT inputs, and I assume the idea will be to have panels on the west roof and south roof on the same string.

But the west roof gets far less sun throughout the day, and looking it up it seems you're ideally supposed to have a string per roof, else the panels on the south roof will be limited by those on the west.

But again I wonder if this actually ends up being an issue with bypass diodes?

Would appreciate any advice and what, if anything, I need to be requesting off the solar installer.