Solar panels and battery - any real world reccomendations?

[Mercenary Keyboard Warrior]

I still don;t think I'm too bad tbh, with interest a 20 panel system with 7l inverter and 9.6kwh battery will be 13,571 all in. Which still seems OK.

Its ok I agree. I don't think its super low.
Almost the same price I paid for 14 panels, 5kw inverter, whole house backup (approx £1k option then), 12.3kw but 11kw "useable" battery

I say useable as they seem pretty optimistic in regards ability in the real world.

Honestly though my advice would be to anyone thinking about it to just do it.
Unless their usage case was just plain daft.

 

[rodders]

My original system, installed in December 2015 paid back by 2021 to 2022 roughly, I did have a spreadsheet with it in, but can't find it. Our 4kWp SolarEdge system was £6600 in 2015, as you say its money spent and nothing you can do about it. I highly suspect your missing something in your calculations (did you include FITS payments), or your a very low user, but then you should be getting paid reasonable money for export. I changed my deemed export to paid export on Octopus.

I keep going over my calcs to see if I'm right or not lol.
I'd say we are medium users 2016 and 2017 using 4200kwh a year

Now we are down to 2600kwh per year, so saving 1,600kwh per year

Yes, included the FiT payments.

I could go to export on Octopus, but what if they change their minds lol.

 

[b0rn2sk8]

I keep going over my calcs to see if I'm right or not lol.
I'd say we are medium users 2016 and 2017 using 4200kwh a year

Now we are down to 2600kwh per year, so saving 1,600kwh per year

Yes, included the FiT payments.

I could go to export on Octopus, but what if they change their minds lol.

Are you sure your real consumption hasn't changed and its being hidden by the solar?

 

[rodders]

It could well be, I'm only basing my savings on what we used to use in 2016 and 2017.
I don't know what I'm using and what's going out as export, we did have an Owl meter which told us, but then they wanted a yearly subscription. Solar installer never told us this and I did t want to pay it, albeit it wasn't a huge cost.
I guess I have no way of knowing....

 

[b0rn2sk8]

If your smart meter is measuring export, you should be able to work it out. You should have a generation meter on the solar, knock of your smart meters export reading and you'd calculate the difference as what you have used in your house.

Your meter doesn't need to be reporting readings to your supplier, it will not be if you are on FIT, it should still be recording them and you could be able to access the reading on the unit itself.

Unless you overpaid for your system it should pay off in 6-8 years on FIT (south facing, probably closer to 10 for east/west) , that was very typical almost regardless of when they were installed.

 

[rodders]

I've never seen an export value on my meter or smart meter. The main meter just displays 'red'
We are south facing.
I'll have another look tomorrow on the smart meter.
Or as I over paid, I'll just say "it will be paid off in 10 year's" lol

 

[Ron-ski]

I could go to export on Octopus, but what if they change their minds lol.

What do mean, change their minds?

PS. You'll need to press the correct buttons on the smart meter to see the export reading, it should have recorded export, mine always have, both my original and the more recent one.

 

[b0rn2sk8]

I've never seen an export value on my meter or smart meter. The main meter just displays 'red'
We are south facing.
I'll have another look tomorrow on the smart meter.
Or as I over paid, I'll just say "it will be paid off in 10 year's" lol

As @Ron-ski said, there should be a register for export in the smart meter somewhere. All smart meters should be bi-directional and record export. Mine you have to dig into the menu's to find it, it is something like: menu button > scroll though to 'registers' > scroll through to 'cumulative export', its about 6-7 button presses to actually get to it.

EDIT: the other thing to check is to see if you are getting the expected generation per the projection you should have received on install. Your FIT payments are based on this so if your panels are not working properly, its not going to pay out a lot.

 

[rodders]

What do mean, change their minds?

PS. You'll need to press the correct buttons on the smart meter to see the export reading, it should have recorded export, mine always have, both my original and the more recent one.

What if octopus decided they aren't going to pay for people exporting, or worse case go bust.
The FiT is guaranteed, albeit not great.

Will get button pushing this afternoon

 

[rodders]

EDIT: the other thing to check is to see if you are getting the expected generation per the projection you should have received on install. Your FIT payments are based on this so if your panels are not working properly, its not going to pay out a lot.

Def producing what they should be, as I was monitoring it and it dropped a few years ago.
Loads of the tigo optimisers popped.
All been changed out to solar edge now under warranty.

 

[200sols]

What if octopus decided they aren't going to pay for people exporting, or worse case go bust.
The FiT is guaranteed, albeit not great.

Will get button pushing this afternoon

They have to provide at least one tariff for exporters under the SEG.

 

[Ron-ski]

I've never seen an export value on my meter or smart meter. The main meter just displays 'red'

Just in case there is some confusion, we're referring to the actual meter, not the in home display - they are usually useless. I think I just had to press button B a few times, but depends on the meter of course.

What if octopus decided they aren't going to pay for people exporting, or worse case go bust.
The FiT is guaranteed, albeit not great.

The deemed export is almost worthless, I was getting 6.79p when I changed mine to actual export with Octopus. 6.79p was roughly £140 a year, and IIRC I actually exporting more than half of mine (prior to expanding my solar), so deemed export was actually paying less per unit. With mine its a different as I've added more solar and batteries, so I export a lot more, so had to change to get paid for that. You really need to work out what you are exporting, and what you can get paid.

As above they have to have a SEG tariff, and if they go bust we'll all be moved to another supplier.

 

[DRZ]

@rodders you might want to look into getting a simple CT clamp meter on your meter tail to monitor your import/export. If your system is reporting generation you'll be able to marry the two up and work out your actual consumption and what percentage of that is coming from the solar. This can be done relatively simply in HomeAssistant so you get an output like this:

That's yesterday, but it can also show monthly/quarterly/yearly summaries as well. From this you should be able to quantify things more easily than with no data at all!

 

[rodders]

Right, data bombardment time....

My Owl meter, whilst it was working from install, Nov 2017, to end of 2019 said I saved £1,090
My estimations for this time came to £1,034, not far off and I've just continued this way to date.
My total estimated savings I have calc'd is £3,661, of which the Fit is £1,782 of this.

Just been to look at my main meter, it was installed 16.03.2020
Import - 11,305kWh
Export - 10,101kWh

Over this same period my panels have generated - 16670kWh, but I did have a period of lower generation, due to Tigo faults.

To date my panels have produced 25,449kWh

 

[rodders]

@rodders you might want to look into getting a simple CT clamp meter on your meter tail to monitor your import/export. If your system is reporting generation you'll be able to marry the two up and work out your actual consumption and what percentage of that is coming from the solar. This can be done relatively simply in HomeAssistant so you get an output like this:

That's yesterday, but it can also show monthly/quarterly/yearly summaries as well. From this you should be able to quantify things more easily than with no data at all!

I wonder if I can adapt the Owl meter tails and use those....

 

[b0rn2sk8]

Right, data bombardment time....

My Owl meter, whilst it was working from install, Nov 2017, to end of 2019 said I saved £1,090
My estimations for this time came to £1,034, not far off and I've just continued this way to date.
My total estimated savings I have calc'd is £3,661, of which the Fit is £1,782 of this.

Just been to look at my main meter, it was installed 16.03.2020
Import - 11,305kWh
Export - 10,101kWh

Over this same period my panels have generated - 16670kWh, but I did have a period of lower generation, due to Tigo faults.

To date my panels have produced 25,449kWh

That shouldn’t be too hard to work out.

You need to calculate how much FIT payment you should have received from 25.5k kWh

And then how much the 6500kwh (16.5k generation minus 11k export) you consumed from the solar since 16/3/20 is worth and then scale that up back to the date of install based on typical energy costs at the time.

I could probably knock something up in 15 mins or so but I’m lazy and it’s your system

 

[rodders]

Was looking up home assistant........yikes......

Anyway, super quick maths, ave yearly consumption off panels is 1642kWh
Multiply that over my whole period to give ~9854kWh and multiply by 18p per unit (kinda the ave) + my FiT payments, gives me a grand saving of £3,556

My other way of doing it gives £3,661

Edit - guess we just don't use enough, to save enough, to make them pay quickly

 

[Ron-ski]

Edit - guess we just don't use enough, to save enough, to make them pay quickly

So you need to maximise what you are being paid for export.

You've exported 60% of what you've generated, yet only been paid for 50%, this has reduced the effective price you get per kWh. Certainly worth looking at moving your export to a proper export tariff that pays much better.

 

[rodders]

You said you split yours, how do you do it?
Does octopus just sort it out, or do I need to talk to Good Energy, who manage my FiT payments?
And you still get the 100% FiT generation payment?

 

[john_smith]

I have a FIT and an export tarrif. My FIT is with EON and my export is with Octopus. When I applied for my export I told octopus my fit details and said I want to keep it with EON (as moving the FIT to octopus would cause a delay). Having an export tarrif means you have to give up the deemed export portion of your FIT payment (it's a tiny amount of £ compared to the actual FIT payment). Howver for me EON have not removed the payment so nearly a year later and 3 payments so far i'm still getting it.