Solar panels and battery - any real world reccomendations?
- Thread starter GinG
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Soldato
@rodders @b0rn2sk8 .
There are two parts to the FITS payments.
1. The generation payment - you get paid for every kWh you generate, regardless of whether you use it or not.
2. The export payment. The export payment can work two ways, it can be metered, or it is assumed you export 50% of what you generate, for small residential systems they are likely to be assumed rather than metered.
The export payments are peanuts, so I moved mine to Octopus and now actually get paid decent money for what I export, I do now have an additional PV system and batteries so the sums stack up, but that's not always case. So depending on what you use, you may be better off moving the export payments from the FITS, adding a battery alters things, but it really depends on the system and use.
When I had just my FITS system and no battery I always ended up exporting more than 50% and getting about 5p per kWh, it really didn't add up to much, in fact roughly £100 for the year for exports.
There are two parts to the FITS payments.
1. The generation payment - you get paid for every kWh you generate, regardless of whether you use it or not.
2. The export payment. The export payment can work two ways, it can be metered, or it is assumed you export 50% of what you generate, for small residential systems they are likely to be assumed rather than metered.
The export payments are peanuts, so I moved mine to Octopus and now actually get paid decent money for what I export, I do now have an additional PV system and batteries so the sums stack up, but that's not always case. So depending on what you use, you may be better off moving the export payments from the FITS, adding a battery alters things, but it really depends on the system and use.
When I had just my FITS system and no battery I always ended up exporting more than 50% and getting about 5p per kWh, it really didn't add up to much, in fact roughly £100 for the year for exports.
Soldato
No, you can split off the export payments and keep the FITS generation payments.
Just checked my last FITS export payment, and that was 6.79p per kWh, that was last April when I switched my exports to Flux - it was cost effective for me to do that.
You can even increase the size of your FITS PV installation nowadays, previously you could only change like for like if you had an issue. If you had a 4 kW FITS array and doubled it to 8 kW, then your generation would be paid on 50%, its pro-rata.
Just checked my last FITS export payment, and that was 6.79p per kWh, that was last April when I switched my exports to Flux - it was cost effective for me to do that.
You can even increase the size of your FITS PV installation nowadays, previously you could only change like for like if you had an issue. If you had a 4 kW FITS array and doubled it to 8 kW, then your generation would be paid on 50%, its pro-rata.
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Really, and you keep the same rate?
Soldato
What are you guys using for your electric import, octopus?
We are on a long fix with EDF but that's about to come to and end. We have a battery but it's only a 5.2kwh givenergy one, so realistically about 4kwh, so I don't think it would be worth going for overnight cheap rates, as I think we might end up getting stung on that?
We are on a long fix with EDF but that's about to come to and end. We have a battery but it's only a 5.2kwh givenergy one, so realistically about 4kwh, so I don't think it would be worth going for overnight cheap rates, as I think we might end up getting stung on that?
i think most of the group will be with octopus (flux)
personally, i just want a tariff that needs no input so i'm with eon and using their EV eco 7 and also eon for the SEG
leccy tariff is 8p between 0000 and 0700 which is when i charge my batteries
SEG tariff is 16.5p/kwh selling
i also have a 4.6kwh (5.12 90% dod) battery and it's cutting close
depends on how much leccy you use
i'm getting a second battery installed for more flexibility so will be fully grid-free during the peak time of my tariff (0700-2359)
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Agile here. If you dont go for a tariff with cheap overnight rates the only other option is tracker.
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I'm on IOG @ 15p fixed. Your Eon tariff is very good.
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I’m in Octopus intelligent go also.
Also consider what load you can shift overnight e.g. dishwasher, washing machine as well as charging. Despite having a big battery (13.5kwh), we still load shift to the cheap periods where we can.
A lot of us have EVs also which makes these tariffs a complete no brainer.
Also consider what load you can shift overnight e.g. dishwasher, washing machine as well as charging. Despite having a big battery (13.5kwh), we still load shift to the cheap periods where we can.
A lot of us have EVs also which makes these tariffs a complete no brainer.
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Soldato
IOG works good for us with two EVs and 20kw storage. Good that other companies have started to compete on a modern stage though. They needed to.
As above, I try and load shift, Mrs Nathan has other ideas though
As above, I try and load shift, Mrs Nathan has other ideas though
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Soldato
Yes, but it pro-rata, double the capacity you get paid for half your generation, triple the capacity and you get paid for a third of the generation. This is what I read on some documents, but not heard of anyone doing it, believe you can also have a DC battery but you will need a bi-directional generation meter.
There's a tiny bit of info https://energysavingtrust.org.uk/grants-and-loans/feed-in-tariff/#:~:text=Changes to your FIT installation&text=You can add additional capacity,for the 'new' capacity.
And a bit more here https://www.ofgem.gov.uk/sites/default/files/2021-12/Feed in Tariffs_Consultation on the treatment of replacement generating equipment_Decision_13122021.pdf
Obviously you need an MCS installer and get approval before altering anything.
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Is anyone tempted to ditch Octopus Intelligent and swap over to Eon Next Drive?
For me the rates on Eon are:
30.46 day
6.9p night - 7 hours fixed between 00:00 and 07:00
49.92/day
16.5p export
Compared to:
27.94 day
7.5p night 6 hours 11:30-05:30 plus additional slots sometimes
47.85/day
15p export
For me the positives are:
no messing around with smart charging
it runs longer into the morning meaning I can heat the house with the heat pump in the morning with cheap grid electricity and not the battery
Slightly higher export rate
Slightly lower overnight import rate
The negatives are
Higher day rate and the battery will not cover the house and heat pump on a cold winters day with limited sun.
Slightly higher standing charge.
I’d say it’s time for a spreadsheet but I don’t have enough solar or heat pump data to do it.
Edit: I’ve not considered savings sessions in the above.
For me the rates on Eon are:
30.46 day
6.9p night - 7 hours fixed between 00:00 and 07:00
49.92/day
16.5p export
Compared to:
27.94 day
7.5p night 6 hours 11:30-05:30 plus additional slots sometimes
47.85/day
15p export
For me the positives are:
no messing around with smart charging
it runs longer into the morning meaning I can heat the house with the heat pump in the morning with cheap grid electricity and not the battery
Slightly higher export rate
Slightly lower overnight import rate
The negatives are
Higher day rate and the battery will not cover the house and heat pump on a cold winters day with limited sun.
Slightly higher standing charge.
I’d say it’s time for a spreadsheet but I don’t have enough solar or heat pump data to do it.
Edit: I’ve not considered savings sessions in the above.
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Soldato
I was looking at it once I get the HP fitted, but as that has been delayed due to unforeseen circumstances I've put working it out back a bit now, not to mention the new car decision is on its head, and that would have complicated matters further as I'd have been using the V2L into the Quattro as a huge battery pack.
I think it is a good option if you don't like to 'force' the IOG cheap slots, and are happy with the guaranteed 6 hours, 7 on EON, period with the better export likely making up for the more expensive daytime rate.
How long will it take you get to get good picture of just HP kWh usage at various temps, and are you using solar diversion for water heating over overnight cheap rates?
I'm on eon next drive + eon set. Works for my use case as my battery will get me through the 0700-2359 higher day rates.
Are you sure eon are only charging 50p daily standing charge? When I last looked the standing charge for the v3 was 60p/day.
(I'm on v2 which is 54p/day and 8p/kWh)
Realistically, a year and we are going into the summer so I’m not going to have any clue for months.
I’ve only had the solar 3 months and time of use tariffs for about 8 (I was on a cheap fix from 2021 for 2 years). I can only really compare back to pre-solar times.
Standing charges vary by region, I’m in one of the cheaper areas fortunately.
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So my 5kW hybrid inverter is clipping my 5.88kW array.
Currently I have two rows of 7 panels on a south facing roof. Each row is on a separate string.
The inverter is connected to a battery with a discharge rate of 3.6kW
I think I'm at the limit of the system as I have no roof space left, but the inverter is just bothering me!! It means a 6+kW draw from the shower always needs grid injection and it means the maximum export to grid is 5kW if there is solar but only 3.6kW if discharging battery.
I have GivEnergy gen 2 battery and gen3 inverter.
Any cheap(??) improvements to this??
Currently I have two rows of 7 panels on a south facing roof. Each row is on a separate string.
The inverter is connected to a battery with a discharge rate of 3.6kW
I think I'm at the limit of the system as I have no roof space left, but the inverter is just bothering me!! It means a 6+kW draw from the shower always needs grid injection and it means the maximum export to grid is 5kW if there is solar but only 3.6kW if discharging battery.
I have GivEnergy gen 2 battery and gen3 inverter.
Any cheap(??) improvements to this??
Soldato
Nope, sadly this is a huge issue with installs where the installer doesn't do their due diligence and ask the right questions of the customer or inform the customer about the limitations of the system design. Sometimes I think they still think they are only installing a solar setup based on FIT, not on modern generation, consumption and battery storage combined with smart tariffs.
You could contact your installer and ask for a price to swap out the inverter and have the DNO G99 updated, probably wouldn't be worth what you'll spend save for at least a decade.
How is Eon customer service? How do they pay export? Both of those are good with Octopus so worth considering.