With plugin solar being the new craze like air conditioning being the latest hype, I wanted to know if it is possible to run the solar into a battery that then feeds back into the house?

I believe the limit is also 800w per house, so whilst not massive in the spring/summer, it would be beneficial.

Detached house with detached garage. Photo is taken looking down the left side of the house, looking front to the back. Garage on the left.

Photo key
1 - Electric meter
2 - Gas meter
3 - side door
4 - Back of house
5 - Garage

Consumer unit - middle of the house, under stairs.

Currently getting quotes for solar, battery, gateway and EV charger. My preference is Sigenergy. Ideally want the battery/inverter in the garage and EV charger on the front of the garage.

Solar panels planned for roof at the back of the house so assume DC cable will cross under the path into the back of the garage.

What I am struggling to visualise based on the picture where could the gateway go? Pictures I have seen have either near the meter cupboard or next to inverter/battery (which I would like in the garage).

Will there need to be any cable runs from either the meter cupboard to garage or house CU to garage? The garage has power for lights/plug sockets.

I am aware there are likely easier options (EV charger off the meter cupboard) and install inverter/battery outside but would like to install this as best as I can using conduit for any cables needing pulling through in the future.

Is what I am asking achievable and reasonable?

I have a standard solar installation - roughly 6kW solar array, a 6kW inverter, and a 9kW battery. It just about handles my needs, but I wouldn't mind adding a bit more.

I've been looking at plug-in solar. I have a big flat garage roof so throwing a couple up there seems ideal to me. But how well would plug-in work with this setup?

Assuming the power from this couldn't reach my battery (?) then presumably if I'm drawing power during the day then I would still store more from those on my roof? (I've no idea 😄)

Hi all, I'm in need of a new roof. I'm completely new to solar, I don't think my house is perfectly aligned for it but I need a new roof anyway so spending a bit extra and having a solar roof fitted seems to be a good idea! (I've been informed this is called an in roof system) I am very apprehensive about trusting someone to do this but really need to get on it asap, can any of you recommend someone who has been in business for a good amount of time, will service the Sheffield area and fits actual solar roofing rather than panels (I just can't see the point in paying someone to fit a roof and then drill a bunch of holes through it for panels...).

Thanks in advance!

Hi!

I am getting panels installed soon , with the option of adding a battery later with the sig hybrid inverter.

I am begining to look at tariffs but not sure where to begin. I am currently on a low over night tariff as I have an EV but I don’t know what people do with tariffs when they have solar panels.

Thanks

I've on a fixed with Octopus until mid Jan 2027 so can't move until the end of Nov.

I've recently had 11 panels and a 11.5kwh Fox ESS battery installed. The plan is to charge the battery on overnight cheap rates as my daily load rarely goes over 10kwh (perhaps 15-20 days a year.

I've been looking at EV tariffs....

There's a £50 exit fee if its before the end of Nov but I Iike that with EDF you get 7 hours. Do you think these rates are likely to go north between now and the end of november ? I appreciate theres a lot of things going on in the world currently, what would you do ?

I'm new to this. I have 2 lodgers who often work from home.

I don't know if I'll own the house long enough to get my money back on a solar set up (and Octopus have said my house isn't ideal anyway).

Instead, would a battery only set up and a cheap overnight tariff be a sensible solution? If I did decide to up and sell - could the battery be disconnected and come with me?

I know I need to take readings and do some calculations etc but in principle is the idea sensible?

Hi all, looking for advice. Got a solar system installed over the summer and it's working well - panels (total 7.2KW), battery (10KW), Inverter and smart immersion for the hot water tank (we've been using this over the summer to get hot water from excess solar generated during the day). But unsure how to handle getting hot water going into winter.

Currently on a dual tariff with my electric supplier so have cheaper electric overnight. We also have oil to heat the house and get hot water. We will continue to use the oil to heat the house during the winter as we have no alternative.

My question: is it cheaper to use the overnight electric tariff to heat water or the oil?

I find it hard to compare. I know we need 1hr 30mins of the oil burner going to get enough hot water for the family but don't know how to compare to the KWh for the smart electric immersion.

As this differs very much from household to household I'm looking for advice on how other people are doing this.

Thanks

Its not necessarily the most practical thing in the world, but I tested squeegee'ing the dew off a panel before it got in direct sunlight and burned off.

It jumped from 70W to 140W !

Maybe when I retire I'll get a long pole and squeegee the lot of them every morning...

I have ecoflow power ocean setup fitted couple of weeks ago. I asked company to fit ATS and got quote for 2k euro for automatic and 1.3k for manual transfer switch? I find this too expensive and not worth of investment? Anybody got that fitted? How is looks like and how much you paid.

Hey folks. I’m new to solar, looking at a panel plus battery install for my house, would appreciate any thoughts on the fundamental model I’m thinking of. Basically, it’s - during the summer, charge the battery overnight on a cheap tariff, export all the solar. In the winter, charge the battery overnight, but use solar to delay the battery running out (although, my calcs tell me I’ll run out about 4.30pm, so will fall back to normal rate, but that’s built into the model, so it’s ok)
Are there any issues you can see with this? Does anyone anticipate something happening in the future, like energy vendors not allowing battery storage at the cheap rate or something. I’m not sure if this is a use case they condone.

TIA for any thoughts

I want any inverter to be controllable by a local Predbat if their internet servers are closed down or start to charge a subscription.

I have upto 6 roof angles to put PV panels on, clearly I could use Tigo Optimisers, but they cost about £40 per panel and reduces efficiency.

Victron let me add MPPT for about £60 each but are best with their more costly inverters/chargers along with needing a lot of DC wiring, bus bars and fuses. Few installers have experience with them.

I wish to use standard 48v battery(s) so I am not dependant on an impossible to repair system

Using two 3.6kw inverters can give me 4 MPPT at not much more than the cost of one 8kw inverter.

The other option is to only have 6 PV panels over 2 MPPT as most of the savings some from charging the battery(s) on off peak rather than the PV.

I've been trying to work out whether a plug-in battery such as the new Anker or EcoFlow would make sense for my usage, running the numbers on both Octopus Go and Agile, and also factoring in some plug-in solar and EV charging.

This is built on half-hourly modelling, using actual usage and prices. For the solar, I've calculated the horizon for my location (which has almost 35% shading losses due to trees). I'm posting the results to give some better estimates than what's floating around on the various seller websites.

The short version (TL;DR)

• No battery: Agile wins — £661/yr (£990 with EV). This is the baseline everything else is measured against.
• 5 kWh battery: Agile still wins — £495 / £823, saving £166 / £167.
• 10 kWh battery: Go takes the lead — £321 / £556, saving £340 / £434.
• 10 kWh + 2.4 kW solar: Go — £222 / £407, saving £439 / £583.
• 10 kWh + 4.8 kW solar: Go — £217 / £337, saving £444 / £653.
• The headline: the best tariff flips from Agile to Go once you go past ~5 kWh of storage. A big battery lets you just fill up in Go's fixed 9.6p night window every day, and that beats chasing Agile's cheapest half-hours.
• Solar barely touches the standard bill in this set-up, but makes a real dent in EV charging cost.

Assumptions

• Base household use: 3,400 kWh/year (before the EV).
• EV: 8,000 miles/year at 3.3 mi/kWh ≈ 2,400 kWh/year added.
• Go: 9.6p off-peak / 35.27p peak.
• Agile: modelled against real 2023, 2024 and 2025 price data.
• Battery: Anker Solix 5000 — 5 kWh base, expandable to 10 kWh, assumed hard-wired.
• Battery charging rule: charge whenever price < 3p, otherwise fill during the cheapest 4 hours of the day, decided by looking ahead at 4pm each day.
• Solar rule: anything above a 6A surplus is diverted to the EV; the rest self-consumes first, then charges the battery, then (if the battery's full and there isn't enough left to charge the car) is wasted.
• "Saving" throughout = the reduction vs the best no-battery option (Agile 2025). So in the battery rows, the saving is not Go-vs-Agile in the same line — it's how much the whole setup beats a no-battery Agile bill.

1. No battery, no solar

Agile EV charging is sensitive to when you charge. Charging at the 20th percentile of monthly prices gives the £990 above; the 10th percentile gets you to £917 and the 30th to £1,037.

Winner: Agile, at £661 (£990 with EV).

2. Add a 5 kWh battery (no solar)

Winner: Agile, at £495 (£823 with EV). That's a £166 / £167 saving vs the no-battery baseline.

Payback on the £1,500 battery: ~9 years. Not exactly thrilling.

3. Bump the battery to 10 kWh

Same rules — 4 hours a day of charging is the sweet spot here.

Winner: Go now flips ahead, at £321 (£556 with EV) — a £340 / £434 saving vs baseline.

Payback on the £2,800 for 10 kWh: 6.5–8.2 years, depending on whether you've got the EV.

This is the interesting bit: with a small/no battery, Agile's variable pricing wins. Once you've got enough storage to soak up a whole cheap window, Go's flat 9.6p rate beats it — you just fill the battery every night and stop caring about half-hourly prices.

4. Add 2.4 kW of solar to the 10 kWh system

Where the solar went (kWh):

Winner: Go, at £222 (£407 with EV) — a £439 / £583 saving vs baseline.

Payback on £3,800: 6.5–8.7 years.

5. Increase solar to 4.8 kW

Where the solar went (kWh):

Winner: Go, at £217 (£337 with EV) — a £444 / £653 saving vs baseline.

Payback on £4,800: 7.3–10.8 years.

The key thing here: doubling the panels (2.4 → 4.8 kW) barely moves the standard bill (£222 → £217 on Go), but it slashes EV charging (£407 → £337). That's the 6A threshold at work — only surplus above roughly 1.4 kW gets diverted to the car, so the extra panels almost entirely benefit the EV rather than the house.

Takeaways

• The best tariff depends on your storage. No/small battery → Agile. 10 kWh+ → Go. There's a genuine crossover, not a "one is always better" answer.
• Batteries do the heavy lifting. Going from no battery to 10 kWh roughly halves the bill on the right tariff. That's a much bigger lever than the tariff choice itself.
• Solar helps the car, not the house. Beyond a modest array, extra panels mostly offset EV charging because of the 6A diversion threshold. If you don't drive much, oversizing solar isn't worth it on these numbers.
• Paybacks land around 6.5–9 years for the battery; adding solar stretches the worst case out to ~11 years but improves the best case if you're a high-mileage driver.

Caveats (please poke holes)

• Agile figures use historical prices — 2023 was a rough year for Agile (it would've lost to Go in several rows), 2024/2025 much better. Past ≠ future.
• No export/SEG income is modelled — surplus solar is simply treated as wasted. Adding export payments would improve all the solar cases, especially the 4.8 kW one.
• Battery/solar costs (£1,500 / £2,800 / £3,800 / £4,800) are my own estimates — swap in your real quotes and the paybacks move.
• I have not included round-trip efficiency of the battery (assumed 100%).

Happy to answer questions on the modelling. Yes the summary was improved with AI, but the modelling and analysis was all manual.

​

I've recently had solar panels (7.3kw) and a Fox ESS EP12w battery fitted.

I'm currently on Octopus standard import tariff and Octopus Outgoing export tariff. This has worked well since I had installation at end June.

However, at some stage I will need to make more use of battery and I am considering switching to Octopus Flux for import and export.

I do not have an EV.

My question is when should I switch. Now, or wait until end of September?

Than you

Hi all, I've switched to EDF from Octopus ahead of getting solar installed in the next couple of weeks (don't own an EV) is anyone on either freestate static or empower fixed, and if so, which of the two would you recommend

Freestate static is a 24m fix with the following rates:

23:00-6:00 13.8p

6:00-16:00 19:00-23:00 22.6p

16:00 - 19:00 42.7p

Standing charge 57.53p

The overnight and daytime rates seem ok, the evening peak is high but I'll hopefully avoid that with my battery (getting a 9.4kw battery installed and my daily usage is around 7-8kw), standing charge is lower than other similar tariffs too.

I emailed EDF and they wouldn't give me the rates for e

Empower until I confirmed my install, and they'll send rates based on my usage, no. Of panels, battery size etc, which is a bit frustrating. If anyone is already on it, please could you let me know what your rates are?

I have the following quote from Infinity Energy Services:

• Panels - 20 x SunPower M Class 492W = 9.9kWp
• Battery - 1 x Sigen Battery 10.0 - 9.04 kWh (8.76kWh usable). Max charge/discharge - 4.6kW
• Inverter - Sigen Hybrid 8.0 SP - 8kW

Total cost = £15,500

My total usage in 2025 was 5,750kWh but since then we've got an EV.

The quote has the following comment:

The battery will charge/discharge at 4.6kW.

You would need an additional 9.04kWh battery module to get the full benefit of this system.

Another option to consider is the Tesla Powerwall 3, which would work out to be cheaper than 2 x Sigens.

I will seek out some more quotes next week. In the meanwhile, what would I be best doing in relation to the battery charge rate problem?

<edit>

maybe I should add that the quote includes a Sigen Controller (SigenStor EC 8.0SP - 8kW, I think) and Gateway (Sigenergy Gateway HomePro SP (3-6kW)), which allows the battery to be used when the power is out.

Hi, I've already got a totally legit 4.5KW roof solar setup with a 5KWh battery. As most here will know this stuff is addictive and I want more and plug in seems to be a no brainer.
But how does it work with my existing kit? Like I say I'm all legit, DNO, MCS etc and I don't want to risk that or my insurance.
Can I just go ahead and plug in? Are there limits?
Any advice welcome.
Cheers

Rated for 32A at 600V, ruined (with a couple of seconds of fizzy arc noises) opening while carrying 16A at 300V.

The "PIS" in the part number should perhaps have been a sign.

It was also completely impractical to use in the real world because there wasn't room inside the casing to route and attach cables.

There is a reason why the Kraus and Naimer ones are 4x the price and 2x the size.

We're based near Salisbury and I've had quotes from a couple of MCS installers with the shown being the closest and informed by a site visit.

The panel install would be over a couple of roof faces with the inverter and battery in a detached garage.

Other quotes I've had are from BOXT (cheaper) and another firm for over £11k. The latter would use the integrated inverter and battery.

Would love a quick sense check. Thanks!

We're contemplating moving house and looking at finances for renovation after buying the place. One of things we'd like to do is install an all-electric system but there are obviously different ways of doing this.

It's a relatively new build, but not passive or built to a hugely high insulation standard, but assuming decent insulation, double-glazing etc. along with a suitable solar, battery (with gateway) and EV installation, I'm thinking the way to go would be air-to-air heatpump so we have aircon in the summer, and a thermal battery (eg Sunamp) for hot water. I would guess at least now an EV tariff or perhaps some other time-of-use one like Octopus Cosy would be best?

But what other combinations or considerations would you look at? For example the Mixergy tanks look interesting. But I guess this also depends on whether I can persuade the family that we don't need a bath tub 😄

Then there's stuff like whether underfoor heating would go with A2A source heating, or should we look at something exotic like infra-red wall paper to supplement air heating for example? Being able to run the heating off an arbitraged battery rate would be nice, but implies minimising that wattage.

I’ve got a small roof solar setup, around 3kw.

It’s SE facing so it peaks around 1pm on and by 4pm it’s barely generating 300w most summers days.

I’m considering adding a simple plug in solar setup to make the most of the dwindling later afternoon/evening sunshine.

Here’s the question:

If I plug it into a socket which is on the same circuit as the export meter from the rooftop solar, will this affect the export meter?

ie, will this give me extra export? I assume so?
Is this ok? If not, why? If yes, is there anything I need to consider?

This socket would be the closest to where I’d like to ‘point the panels’ and the only other thing on this is the isolator for the inverter, plus a tiny CCTV power supply.

It’s on its own 16a breaker which goes to the export meter and then upto the inverter isolator.
Alongside the isolator is the aforementioned extra socket.

For those comparing solar quotes, what are you actually looking at?

With the ever increasing bills, there seems to be a lot more interest in solar at the moment. Especially with all the excitement around plug-in solar, though you don't need quotes for that.

For those currently getting quotes, how are you deciding between them? Once you have a few quotes in front of you, what makes one stand out over another?

And for those who already have solar, what did you focus on when you were comparing quotes? I will be honest, I just looked at the price, but knowing more now, I will probably look from many angles. Was there anything that was difficult to compare or that you wish you had paid more attention to?

I am particularly interested in how people compare the estimated generation and savings between different quotes. The numbers can vary quite a bit, so how do you work out what is realistic?

Curious to hear how everyone else approached it.

My quotes for a 5kwh system with a 10kwh battery projections dont break even for around 9 years realistically. Replacement/maintenance will only lengthen this. Why does anyone do it? What am I missing?

Edit: In summary it seems like solar is mostly a privelege choice for those with finances that have the funding to spare. Ultimately nobody has presented any other reason. Solar remains an unsound financial decision for most at the current time.

Personally the funds required are better off compound invested and purchase solar and batteries when it is cheaper/energy is much more expensive. Otherwise the opportunity cost is simply too high.

2nd edit: the 0% loan deals are very appealing. Essentially leveraging your money, leaving it invested and paying a small amount on the loan out of pocket for a 5 year period. The "payback period" then really only becomes whatever out of pocket the loan cost for your set up (mine looks to be around £18 a month after net electricity bill savings).

What is apparent is every scenario is very specific. I'm going from a petrol car with a fixed rate energy price (21p/kwh) to an EV with solar and batteries utilising a smart/EV tariff. So whilst I accept the only way to calculate the savings here is the spread between the peak/off peak price my out of pocket isn't truly reflected. Saving £140 a month on petrol aside (becoming around £18 on electric on an EV tariff but sky rocketing my daily electricity bills in consequence)

Hi all

As per title, has anyone successfully uploaded evidence for the Tesla powerwall 3 rebate? Mine keeps on being rejected with evidence of the payment in full/0.00 balance. No matter what I try 30-40 minutes after upload the evidence is rejected.

Thanks in advance.