Solar panels and battery - any real world reccomendations?

[Richie]

I use 1100-1200 kWh/year and I am out of the house during the day

I have a South facing roof with around 9m² of useable roof space for panels.

Given this, and assume best case scenario with panel efficiency, am I right in thinking that I am unlikely to recover a solar install for circa 10-12 years?

What would a decent battery setup bring this payback down to? (I use an average of 3.5 kWh/day but that will be more in Winter)

Worth getting it?

 

[HungryHippos]

I use 1100-1200 kWh/year and I am out of the house during the day

I have a South facing roof with around 9m² of useable roof space for panels.

Given this, and assume best case scenario with panel efficiency, am I right in thinking that I am unlikely to recover a solar install for circa 10-12 years?

What would a decent battery setup bring this payback down to? (I use an average of 3.5 kWh/day but that will be more in Winter)

Worth getting it?

I'd argue your usage is too low to really make it worth it.

At new cap rates of £0.52, your cost for those units is £600 tops for the year, £50/month.

Install for a reasonable system is likely £5 - 6k without a battery.

You'd probably be approaching a 10 year payback and you still need the grid in the winter.

If you have a large garden etc you could look at getting a much cheaper ground mounted system added, with a small battery perhaps.

If you have an EV you can get onto Octopus Go, then installing just a battery can also make sense, charge car + battery in off-peak for cheap, don't even need panels.

Saying all of the above, if you have cash burning a hole in your pocket and want to aid the environment etc then you could just do it, it's still likely a sub 10-year payback, and could shrink a bit if higher prices sink in. I'd be looking at ways you can use more electric though to make it worth buying, such as EV, AC.

 

[katie279]

Only extra thought would be what's your heating? Air source + EV might be an option to incorporate and reduce other costs (eg petrol and oil/gas)

 

[HungryHippos]

Octopus Agile outgoing should also pay fairly well for generation if you want to try and max payments for excess generation, over-producing a lot I think that would provide the best return.

 

[Journey]

I use 1100-1200 kWh/year and I am out of the house during the day

I have a South facing roof with around 9m² of useable roof space for panels.

Given this, and assume best case scenario with panel efficiency, am I right in thinking that I am unlikely to recover a solar install for circa 10-12 years?

What would a decent battery setup bring this payback down to? (I use an average of 3.5 kWh/day but that will be more in Winter)

Worth getting it?

I'd look at a micro-inverter (3-pin plug) and a couple of ~300w panels, should cost about £300-350, and mount them on a shed/ground/against a fence. Just need an electrician to setup an external socket, and maybe an IP65 rated box for the inverter if you don't get one that is already rated. That would cover a lot of the day time usage. If you wanted to co further you could get a cheap DC connected batter/charge controller and either some AGM Lead Acid batteries, or some LiFePO4's and have a store for evening, add another £500+ for that.

EDIT: Something like this one is already rated for outdoor use, and you can connect two panels with a Voc of 36-50v which is a good range.

 

[Mercenary Keyboard Warrior]

Hi everyone

I was just wondering if there might be any advice - I'm considering to put up a battery store for my solar array, since the cost of the electric is getting rather shall we say stupid and leave it there... I was just curious if anyone had a particular 'go to' for battery make/models at all?

I've been on to Effective Home's website and they mention they use GiveBat's batteries which go up to 9.5kW, which I thought seemed a little overkill in a way, but a good storage amount should we ever need it or things change? Whilst I'm looking to move from the property I'm in, I thought it seemed a good practice to possibly get a decent setup done with this property and then replicate it on the next. I don't think I'd be without my solar array after having one, regardless of the FIT not being there anymore sadly.

I've a 3.6kW array with 12 x 305w JA Sun panels (I think that's the correct name for the panels!) and a Growatt 3.6kW or 4kW inverter. Sadly no monitoring system as the Geo 3 I believe it was called that was meant to go in didn't because I was told it was against regs and never really liked the way it was installed... So I moved on

Is there anyone with a bit of advise with regards to what I should be looking for, for the battery setup??

Don't take this as gospel but from the two installers I talked to they said you cant mix and match everything right now, too many bits of custom software etc running in these systems.

To go battery with your panels I think you need to get an hybrid inverter fitted to replace your old one, and that can then manage the panels and battery

Depending how old your system is a new inverter isn't a terrible thing, from what I can ascertain they are the weakest part of the solar systems. Many only have a 5 year guarantee and even the longest seem to be 10.
Panels are often 25 and now starting to be 40 for some makes.

Do you have FIT though, because from what I read you need to be careful on what you do as many things can invalidate it.

 

[Freakbro]

How are things with supplies of batteries. We had the panels fitted at the end of July, but they said the batteries were out of stock estimated due by the end of August, but still no joy yet.

 

[OldKitMan]

Could you put in a G98 application and a G99 at the same time? Have the inverter switched to 3.68kw mode until the G99 is approved?

Would it not need to be a G100, don't see hour G98 comes into this.

 

[phill9800]

Don't take this as gospel but from the two installers I talked to they said you cant mix and match everything right now, too many bits of custom software etc running in these systems.

To go battery with your panels I think you need to get an hybrid inverter fitted to replace your old one, and that can then manage the panels and battery

Depending how old your system is a new inverter isn't a terrible thing, from what I can ascertain they are the weakest part of the solar systems. Many only have a 5 year guarantee and even the longest seem to be 10.
Panels are often 25 and now starting to be 40 for some makes.

Do you have FIT though, because from what I read you need to be careful on what you do as many things can invalidate it.

Many thanks for the details Well the Geo isn't connected, so that's out the way altogether, I basically have the inverter and the panels and that's it, there's sadly no monitoring on the system at all. If I'd like to see what its producing, I have to tap the front of the inverter to show me what its doing. (Its a Growatt model)

The system will be coming up to 5 years in a few weeks but has been as far as I can tell, no problems at all. I understand that inverters seem to be the weak link in the chain which I don't understand how but that's another question for another day. I be my JA Panels are 25 years? (I think....)

I do have a FIT tariff for the moment, if I can't do anything because of that, then so be it, I'll just use that cash to cover the costs of the electric I'd use overnight (in a way) so it might be worth messaging maybe British Gas (who my FIT is registered with) and see what they say I could do or can't.. Worth a shot I think since it's only a short email
If I don't do anything for this house, then the next house I'll definitely be adding in a battery system to it and I'd make sure I'd have the biggest array I could manage (although I did think it was limited to 18 panels for home?? But not sure if that counts now as I've seen some houses with far more on them.... Read on a site last night someone had 28... )

Thanks again!!

 

[Ron-ski]

@phill1980 You could look at an AC connected battery (this won't alter your current installation so won't affect FITS payments), it will monitor when you have excess solar and charge the battery. They use a CT clamp on your main cable from the grid, so it can tell if you are importing or exporting power.

As you have 3.68kw of panels/inverter you'd need to apply for a G99 permission from you DNO as they will take the existing 3.68kw and whatever the AC connected battery can produce, and add it together and see of the local grid can handle that much power.

 

[Journey]

Good read here on how effective Tesla PW's have been when used as utility scale grid offset.

Let's hope that more manufacturers start offering such a scheme so that we can all benefit in reducing peak loads, and therefore fossil fuel use. It is also going to be time soon to have this working for cars and V2G.

 

[Welshman]

Where do you all have your inverters and batteries situated…..my installer wants to put them in the attic, does anyone else have them up there and are they doing ok in there???

 

[Bug One]

Was in the attic in my old house. In the current house it's in the garage next to my consumer box.

 

[HungryHippos]

Very happy with performance so far, only have 4 days worth of data but generated 10 - 17kwh per day, which is enough to subsidise a lot of my usage.

I know this won't stay at 10 going into the winter properly, but will be interesting to see how September does in general.

Still getting used to how it performs in varying weather/times of day, I charged the battery fully last night but I could have left some room to breathe, battery was fully charged from solar at about 6PM and I was just running stuff to use some power up.

Despite that, still exported a little today, so I will adjust the battery charge level a bit lower.

 

[welshdragon]

Getting a solar quote in south wales is like pulling hens teeth….the company i am using is from Bolton

Ive found what I hope will be a decent one, emailed me back same day, very thorough project proposal and I've just pulled the trigger

 

[TNA]

Very happy with performance so far, only have 4 days worth of data but generated 10 - 17kwh per day, which is enough to subsidise a lot of my usage.

I know this won't stay at 10 going into the winter properly, but will be interesting to see how September does in general.

Still getting used to how it performs in varying weather/times of day, I charged the battery fully last night but I could have left some room to breathe, battery was fully charged from solar at about 6PM and I was just running stuff to use some power up.

Despite that, still exported a little today, so I will adjust the battery charge level a bit lower.

Interesting. How many kilowatts is your panels? Also which side is it facing?

Still umimg and aring here whether to go solar or not, even though previously I said I would wait. But **** seems to keep getting worse ffs

 

[HungryHippos]

Interesting. How many kilowatts is your panels? Also which side is it facing?

Still umimg and a ring here whether to go solar or not, even though previously I said I would wait. But **** seems to keep getting worse ffs

I have 13 panels in total roughly 50/50 SE/SW, for a total of 4.8kw.

Last few days haven't really been great weather wise, dreary/overcast with a bit of sunshine, so happy with performance even though conditions aren't ideal.

None of these days have been sunlight all day long at all, I'd love to see what the system can do on a clear day.

 

[Welshman]

Ive found what I hope will be a decent one, emailed me back same day, very thorough project proposal and I've just pulled the trigger

Who you going with???

 

[gpuerrilla]

Last few days haven't really been great weather wise, dreary/overcast with a bit of sunshine, so happy with performance even though conditions aren't ideal.

None of these days have been sunlight all day long at all, I'd love to see what the system can do on a clear day.

Been drab couple of days here too, hoping weather tomorrow improves to get the tank heated again!

 

[Werewolf]

I have 13 panels in total roughly 50/50 SE/SW, for a total of 4.8kw.

Last few days haven't really been great weather wise, dreary/overcast with a bit of sunshine, so happy with performance even though conditions aren't ideal.

None of these days have been sunlight all day long at all, I'd love to see what the system can do on a clear day.

We hit our lowest production day on Friday with our 12 SSE facing ones (4.7kw array), about 7kw produced.

On a good day we've been hitting 30 with ease, the average has been 20-25ish over the last month. Apparently we've got something like 700kw since the end of July.