Sig Energy Solar Installation

[Doug99]

Hi All
I have just had a 13 panel and battery Sig Energy installation and now spending the day toying with the app watching the figures of solar generation during this perfect sunny day with no cloud in the sky.

Now waiting for the certification and other details from the installer to enable me to sign up to an input/export tariff with my current provider Octopus.

The SigGen app is showing a lot of info and I've selected the AI mode which I assumes will monitor my usage over the next few days and offer advice on how to manage it more effectively.

Does anyone have any tips on its management and what export tariffs are suitable? I do NOT have an EV so only a standard household consumption is involved.

Cheers All

 

[ericmark]

Different make, but same situation. I have been looking at the tariffs, not easy as you need to enter your post code to get a quote. But the big question is how long does your battery last?

So yesterday 5:32 am, day before 5:45 am, day before 4:00 am, day before 3:30 am, day before that had an off-peak supply, and in the morning the state of charge (SOC) was 80% lowest in the morning around 8:20 am, and 50% at 1 am when the off-peak cut in.

With those figures mine going back as far as it would let me, at 7 pm only twice was I drawing power from the grid, so a tariff with a massive 36.06p per kWh from 4 pm to 7 pm is not a problem, as I am unlikely to need to pay it.

Octopus "Go" and British Gas EV (don't need an EV with BG) are very similar, I failed to get export payment from BG, and Octopus "Go" only pay 8p per kWh for export, not got Octopus rates, but BG was 8.95p off-peak and 31.31p rest of the time. I went from this rate to standard default rate, and cost has not changed, as I would storing around 3 kWh in battery which was later in the day exported again. With no off-peak last few days, 0.7 kWh to 2.3 kWh with off-peak 6.1 kWh to 8.2 kWh used to charge batteries, so straight 24/7 rate not costing any more as the off-peak rate, over the last week. Clearly, winter off-peak really pays, but the last few days, it has not.

So I am looking at Octopus Flux pays far more for export, 5.12p 2 am to 5 am will not export then anyway, 13.9p after that except for 4 pm to 7 pm when it is 27.73p all per kWh. Against 8p with their "Go" rate. But if you use power, import, 2 am to 5 am 15.45p, then 25.76p except 4 pm to 7 pm when 36.06p per kWh.

I went back nearly a year, and calculated, and I would be about £150 better off with Flux, but it is down to how much you use, generate and store, there is no one tariff fits all.

So mine.

All this month, 4 with and 4 without off-peak. You can see which is which due to Import to User over 6 kWh with off-peak. Cost with standing change.
1st=£1.35p, 2nd=£1.28p, 3rd=£1.19p, 4th=£1.16p, 5th=£1.27p, 6th=£1.15p, 7th=£0.93p, 8th=£0.89p, as said change from off-peak to standard not changed total amount paid by much, if anything cheaper without off-peak. Winter, clearly very different.

So how does your solar compare with mine. My battery 6.4 kWh, how big is yours. Battery size needed will change depending on your background use, but with 3.2 kWh charge limit 2 kW and discharge limit 3 kW, now doubled up, so 4 kW charge and 5 kW discharge limit (size of inverter) with the single battery I would see export even when not fully charged, and with discharge easy to exceed 3 kW but normally except for shower I am within 5 kW limit. So second battery as much to stop that to storing more, but with second battery, winter looking at 9 pm before battery runs out most days, but running out 6 pm before second battery, which would mean with Flux I would be paying peak rate, so battery size is important.

 

[morqthana]

 

[ericmark]

All I can say, is cowboy. Who would dream of using an auto-transformer to get around the safety feature, so supply will not raise above 253 volts? Not only did he do it, he made a YouTube video about doing it, I would have kept rather quiet about it, not something you want to broadcast to the world about. But suppose there will always be idiots?

A quick line - neutral earth impedance test, should show how much one can export without an auto stepping transformer. I will admit, it is a little unclear as to permission to export, does it mean they guarantee to take the power, or does it say if the parameters are within limits you can export the power? Would be interesting to see what someone like @flameport has to say.

However, fitting an auto transformer which boosts the neighbour's supply voltage to over the 253 volts limit is clearly a no no.

 

[Doug99]

Different make, but same situation. I have been looking at the tariffs, not easy as you need to enter your post code to get a quote. But the big question is how long does your battery last?

So yesterday 5:32 am, day before 5:45 am, day before 4:00 am, day before 3:30 am, day before that had an off-peak supply, and in the morning the state of charge (SOC) was 80% lowest in the morning around 8:20 am, and 50% at 1 am when the off-peak cut in.

With those figures mine going back as far as it would let me, at 7 pm only twice was I drawing power from the grid, so a tariff with a massive 36.06p per kWh from 4 pm to 7 pm is not a problem, as I am unlikely to need to pay it.

Octopus "Go" and British Gas EV (don't need an EV with BG) are very similar, I failed to get export payment from BG, and Octopus "Go" only pay 8p per kWh for export, not got Octopus rates, but BG was 8.95p off-peak and 31.31p rest of the time. I went from this rate to standard default rate, and cost has not changed, as I would storing around 3 kWh in battery which was later in the day exported again. With no off-peak last few days, 0.7 kWh to 2.3 kWh with off-peak 6.1 kWh to 8.2 kWh used to charge batteries, so straight 24/7 rate not costing any more as the off-peak rate, over the last week. Clearly, winter off-peak really pays, but the last few days, it has not.

So I am looking at Octopus Flux pays far more for export, 5.12p 2 am to 5 am will not export then anyway, 13.9p after that except for 4 pm to 7 pm when it is 27.73p all per kWh. Against 8p with their "Go" rate. But if you use power, import, 2 am to 5 am 15.45p, then 25.76p except 4 pm to 7 pm when 36.06p per kWh.

I went back nearly a year, and calculated, and I would be about £150 better off with Flux, but it is down to how much you use, generate and store, there is no one tariff fits all.

So mine. View attachment 378598View attachment 378599View attachment 378600View attachment 378601View attachment 378602View attachment 378603View attachment 378604View attachment 378605All this month, 4 with and 4 without off-peak. You can see which is which due to Import to User over 6 kWh with off-peak. Cost with standing change.
1st=£1.35p, 2nd=£1.28p, 3rd=£1.19p, 4th=£1.16p, 5th=£1.27p, 6th=£1.15p, 7th=£0.93p, 8th=£0.89p, as said change from off-peak to standard not changed total amount paid by much, if anything cheaper without off-peak. Winter, clearly very different.

So how does your solar compare with mine. My battery 6.4 kWh, how big is yours. Battery size needed will change depending on your background use, but with 3.2 kWh charge limit 2 kW and discharge limit 3 kW, now doubled up, so 4 kW charge and 5 kW discharge limit (size of inverter) with the single battery I would see export even when not fully charged, and with discharge easy to exceed 3 kW but normally except for shower I am within 5 kW limit. So second battery as much to stop that to storing more, but with second battery, winter looking at 9 pm before battery runs out most days, but running out 6 pm before second battery, which would mean with Flux I would be paying peak rate, so battery size is important.

Thanks Ericmark. A lot of info there and a lot to think about when managing the battery. Hopefully the AI mode of the MySig app will offer some info with which to guide me.

For info, my Sig Energy system comprises of:
13 x 440w PV Panels - Configured 7 panels facing south (PV1), 6 panels split 3/3 East/ West (PV2). All fitted with optimisers.
4Kw Inverter/Controller
8Kw Battery.

Yesterday was the first full day of use with total sun (no clouds) and the app is showing:
Produced - 31.5Kwh
To Grid - 17.72 Kwh (not registered for export yet)
Consumption - 10.8 Kwh
Self-Consumption - 7.7 Kwh What is difference between Consumption/Self Consumption?
From Battery - 3.56 Kwh

Yesterday was a good test of the system in the sunshine and I assume it will generate more as the sun climbs higher during the summer season.

 

[Munroast]

Different make, but same situation. I have been looking at the tariffs, not easy as you need to enter your post code to get a quote. But the big question is how long does your battery last?

So yesterday 5:32 am, day before 5:45 am, day before 4:00 am, day before 3:30 am, day before that had an off-peak supply, and in the morning the state of charge (SOC) was 80% lowest in the morning around 8:20 am, and 50% at 1 am when the off-peak cut in.

With those figures mine going back as far as it would let me, at 7 pm only twice was I drawing power from the grid, so a tariff with a massive 36.06p per kWh from 4 pm to 7 pm is not a problem, as I am unlikely to need to pay it.

Octopus "Go" and British Gas EV (don't need an EV with BG) are very similar, I failed to get export payment from BG, and Octopus "Go" only pay 8p per kWh for export, not got Octopus rates, but BG was 8.95p off-peak and 31.31p rest of the time. I went from this rate to standard default rate, and cost has not changed, as I would storing around 3 kWh in battery which was later in the day exported again. With no off-peak last few days, 0.7 kWh to 2.3 kWh with off-peak 6.1 kWh to 8.2 kWh used to charge batteries, so straight 24/7 rate not costing any more as the off-peak rate, over the last week. Clearly, winter off-peak really pays, but the last few days, it has not.

So I am looking at Octopus Flux pays far more for export, 5.12p 2 am to 5 am will not export then anyway, 13.9p after that except for 4 pm to 7 pm when it is 27.73p all per kWh. Against 8p with their "Go" rate. But if you use power, import, 2 am to 5 am 15.45p, then 25.76p except 4 pm to 7 pm when 36.06p per kWh.

I went back nearly a year, and calculated, and I would be about £150 better off with Flux, but it is down to how much you use, generate and store, there is no one tariff fits all.

So mine. View attachment 378598View attachment 378599View attachment 378600View attachment 378601View attachment 378602View attachment 378603View attachment 378604View attachment 378605All this month, 4 with and 4 without off-peak. You can see which is which due to Import to User over 6 kWh with off-peak. Cost with standing change.
1st=£1.35p, 2nd=£1.28p, 3rd=£1.19p, 4th=£1.16p, 5th=£1.27p, 6th=£1.15p, 7th=£0.93p, 8th=£0.89p, as said change from off-peak to standard not changed total amount paid by much, if anything cheaper without off-peak. Winter, clearly very different.

So how does your solar compare with mine. My battery 6.4 kWh, how big is yours. Battery size needed will change depending on your background use, but with 3.2 kWh charge limit 2 kW and discharge limit 3 kW, now doubled up, so 4 kW charge and 5 kW discharge limit (size of inverter) with the single battery I would see export even when not fully charged, and with discharge easy to exceed 3 kW but normally except for shower I am within 5 kW limit. So second battery as much to stop that to storing more, but with second battery, winter looking at 9 pm before battery runs out most days, but running out 6 pm before second battery, which would mean with Flux I would be paying peak rate, so battery size is important.

if charging your battery from the grid (during the night) how long does it take to fully charge your 6.4kwh battery

(i am about to have a system installed and curious about how long the batteries take to charge, from the grid)

 

[ericmark]

@Munroast about an hour and a half, 6.4 kWh / 4 kW maximum charge rate = 1.6 hours, but always leave 10% to run UPS option if we have a power cut.
@Doug99 Likely Octopus Flux is what you want. The thing is you want battery left between 4 pm and 7 pm in the winter most days, as don't want to pay 36.06p per kWh too often, seems likely you will get to 7 pm most days before battery runs out. I note my solar levels out at 5 kW clearly due to inverter is only 5 kW, I have 14 panels, I was at 33.3 kWh yesterday with solar.

I note your panels not all same direction, so likely 4 kW is enough, but when running items need to be a little more careful as easier to exceed 4 kW to 5 kW.

 

[Munroast]

what sets the max 4 kw charge rate ? the inverter ?
we would have a 6kw inverter and 10 kwh batteries

 

[ericmark]

what sets the max 4 kw charge rate ? the inverter ?
we would have a 6kw inverter and 10 kwh batteries

Both, charge the battery limits at 2 kW per battery, so battery is limit, discharge the limits are 3 kW per battery, so the 5 kW inverter is the limiting factor. Before the second battery, we would see charging at 2 kW using 1 kW and exporting 2 kW as not being paid for export, not what we wanted.

Weather today, not a problem, 10 am getting 1.4 kW from solar, panels aimed more for evening sun. But by 11:30 am, likely batteries will be full, well tumble drier and washing machine on, so may be delayed a bit.

 

[Munroast]

Both, charge the battery limits at 2 kW per battery, so battery is limit, discharge the limits are 3 kW per battery, so the 5 kW inverter is the limiting factor. Before the second battery, we would see charging at 2 kW using 1 kW and exporting 2 kW as not being paid for export, not what we wanted.

Weather today, not a problem, 10 am getting 1.4 kW from solar, panels aimed more for evening sun. But by 11:30 am, likely batteries will be full, well tumble drier and washing machine on, so may be delayed a bit.

just looking at the specs for the batteries we are getting (Growatt ALP5.0L-E2) it says the are a "1C" which i think would suggest since they are a 5kwh battery that they can both deliver and accept 5kh ?

and since the inverter is 6KW does that mean transfer from battery to house and vice versa would be a max 6kw, ?
and from panels to battery - does that go through inverter ? could the whole 9kw go into them both at once

 

[JohnW2]

Consumption - 10.8 Kwh
Self-Consumption - 7.7 Kwh What is difference between Consumption/Self Consumption?
From Battery - 3.56 Kwh

Goodness knows what the difference is, but those figures are not far off being consistent with 'Self Consumption' realting only to 'real-time' use of electricity (from PV and/or grid), but excluduing 'secondary' consumption from battery-stored electricity!

 

[ericmark]

Consumption with mine does not include grid or solar to battery. kWh is very confusing, really should be Joules, it has nothing to do with time in spite of having hour in the name.

 

[Doug99]

Edit

 

[Doug99]

Goodness knows what the difference is, but those figures are not far off being consistent with 'Self Consumption' realting only to 'real-time' use of electricity (from PV and/or grid), but excluduing 'secondary' consumption from battery-stored electricity!

To clarify, I was asking of their meaning - I have since noted that Self Consumption refers to that from PV and Consumption is from Grid.

 

[ericmark]

So I have Solar Yield shows produced that day and total, three displays changes when clicked on. Battery charged today and total, feed in energy and click and changes to import (today 0.6 kWh) and consumption is what the house has used today from any source.

It was SOC which I scratched my head over, it stands for state of charge.