Solar Panels UK - is it worth it?

[phil4]

I'm increasing my PowerWalls from 2 to 3.

On best days, this time of the year, I get to 100% (from PV) and maintain that until around 21:30 and then overnight falls to about 25% ... so i have some slack for a following cloudy day.

But on the cloudy day I may fall such that I only just reach Off Peak ... and then the [API ] question is how much to charge during Off Peak

Once I have 3 PowerWalls I'm going to arrive on the cloudy day at much more than 25% (across 3x PWs), so likely to have enough for "tomorrow night" but i suppose I will still like days where "yesterday was cloudy", and I manage to run all three PowerWalls down to 0% just as the sun comes up ... and then they are 100% full at SunDown ... and also needing to handle multiple-cloudy-days-in-a-row.

So (I think) the upgrade is just going to provide more leeway - in particular on the days when SolCast is "way off"

(Of course this upgrade purchase is more to do with Winter and being able to get through the whole day having charged on Off Peak, but also recognising that it allows "Looser" prediction accuracy in Summer PV)

As I don't have any ASHP stuff, nor hot tubs or the like, I'm just about "rightsized on battery", 2 PWs, so notionally 27kWh, but with house use normally around 18kWh. So 9kWh extra for slack. The challenge at the moment is working out a way to deal with Solcast being out, but not much buffer that I hit 100% charge too early. I'm getting there.

 

[MrT3]

bottomed out at 5% overnight and used a bit of grid to keep it there. Slowly topping up now but not sure it'll fill today.

confused as my givenergy settings have a 1:30-6:30 timed charge set to 20% so it shouldn't have dropped below that?

If the battery was already below 20% it should have charged it to that level and maintained it until 6:30 when it would start discharging.
If the battery was above 20% then once it got to 20% it should have maintained that level until 6:30 when it would start discharging.

I recently applied an inverter firmware upgrade and it ignored my charge level settings (it charged it to 100% ) until I switched timed charge off/on and altered all the settings to make sure they were rewritten into the system correctly.

Everything worked as it should be me last night. My battery got down to 5% before it charged up at 12:30 to my 43% setting (I set it a bit higher than normal because of today's forecast but should have gone higher).

 

[phil4]

Bad news, looks like we're set to have July's weather again through most if not all of August: UK weather: When will it stop raining and the summer improve?

 

[Pete UK]

It's been nasty here in Edinburgh too. We were away for most of it fortunately, but limping through just now as we are mid transition to IO so don't have any cheap time overnight .

I got the acknowledgement that I am on IO now. (Emailed Friday night to ask/confirm)

 

[Pete UK]

If the battery was already below 20% it should have charged it to that level and maintained it until 6:30 when it would start discharging.
If the battery was above 20% then once it got to 20% it should have maintained that level until 6:30 when it would start discharging.

I recently applied an inverter firmware upgrade and it ignored my charge level settings (it charged it to 100% ) until I switched timed charge off/on and altered all the settings to make sure they were rewritten into the system correctly.

Everything worked as it should be me last night. My battery got down to 5% before it charged up at 12:30 to my 43% setting (I set it a bit higher than normal because of today's forecast but should have gone higher).

View attachment 961088

Yes there was quite a lot of chat on the GE forum re: inverter(battery) firmware upgrade issues.
Some of the settings getting reset and batteries charging to 100%. Some getting bricked. Not good.

For me I didn’t apply the upgrade - on a Friday afternoon? seems like a bad idea.

I’ve got a different problem right now though unfortunately. One of the 4 batteries just suddenly dropped to and showed 0%. It wouldn’t show it charging! Turning off the battery breakers, leaving 2 mins and back on again (the green ‘handle’ on the left) didn’t help.
Pressing the small black button for 10 seconds (to turn off) didn’t work either. Looks like it bricked itself !

Called out the installer, who spent 2 hours and couldn’t resolve it. I also had contacted GE, who today emailed to say they upgraded the inverters software but it still shows not upgraded and now both batteries on that inverter show 0% (although they probably aren’t on 0%).
The inverter shows its generating and I’ve got no export showing so I reckon the BMS has bricked something! Woes indeed.

The other 2 batteries and inverter seem to be working ok for now. Very strange.

Forced charge/ discharge/ pause / play didn’t help either.

 

[Avendit]

I got the acknowledgement that I am on IO now. (Emailed Friday night to ask/confirm)

Holy schnitzel! Is this what non solar people have to put up with day to day?

We... ran out of solar today. Everyone returned from various camping activities over the weekend so the washer and heated airer has been on double time, and the weather has been atrocious as mentioned, and we are mid swap to Octo and IO so no recharge over night... And the end result is horrible!

Is this normal for the non solar users!? I didnt have a smart meter before the panels so have never experienced a full price day being highlighted to me before. Something shoddy like 6kw from the panels today, battery started empty and we pulled 17kw from the grid.

Please someone bring me the sun back! (Or hopefully get sorted and onto IO soon).

 

[Drew57]

I didnt have a smart meter before the panels so have never experienced a full price day being highlighted to me before.

 

[tomorrowman]

Apologies in advance if this is already covered (life is to short to read this thread) but to the question of is solar worth it in UK

Going through this exercise now. Due to roof orientation, shading etc the best I can hope for is 3000kWh annually. Now with intelligent Octopus peak rate this would equate to approx £900 savings a year assuming I used it all. But once I stick a battery in the mix and have the ability to power house using off peak, which suddenly makes the so-called savings approx £250 annually, which for a £4-8K PV investment is a payback period of decades.

Outcome: Sod the solar, Slap in a GivEnergy All In One battery and payback in under 7-8 years even taking into consideration the VAT I need to pay for a battery only install

 

[Avendit]

Apologies in advance if this is already covered (life is to short to read this thread) but to the question of is solar worth it in UK

Going through this exercise now. Due to roof orientation, shading etc the best I can hope for is 3000kWh annually. Now with intelligent Octopus peak rate this would equate to approx £900 savings a year assuming I used it all. But once I stick a battery in the mix and have the ability to power house using off peak, which suddenly makes the so-called savings approx £250 annually, which for a £4-8K PV investment is a payback period of decades.

Outcome: Sod the solar, Slap in a GivEnergy All In One battery and payback in under 7-8 years even taking into consideration the VAT I need to pay for a battery only install

Why not do the give energy thing and the £900 a year saving of solar? The solar should only be a 4-5 year payback assuming it's element of install is about 5k? Usually the battery is the high capital element, but does stack well.

If you haven't read back much, the second half of this post shows how I approached the calcs, but obviously likely different roofs, demands and installs.

 

[Avendit]

Ah, got you after a re-read. Is the battery big enough to last you 18 hours through the year? This is why in my cals I calc good/medium and bad days separate. Lots of the medium days I would run out of battery and have to pay peak rate without the solar tiding me over, but I'm on electric heating and HW which eats the battery a chunk.

 

[ringi]

Apologies in advance if this is already covered (life is to short to read this thread) but to the question of is solar worth it in UK

Going through this exercise now. Due to roof orientation, shading etc the best I can hope for is 3000kWh annually. Now with intelligent Octopus peak rate this would equate to approx £900 savings a year assuming I used it all. But once I stick a battery in the mix and have the ability to power house using off peak, which suddenly makes the so-called savings approx £250 annually, which for a £4-8K PV investment is a payback period of decades.

Outcome: Sod the solar, Slap in a GivEnergy All In One battery and payback in under 7-8 years even taking into consideration the VAT I need to pay for a battery only install

Its an interesting issues as having a EV gives access to the cheapeet overnight power, but being on such a tariff also exclude the best payments for export unused PV output. Octopus Flux also requires a battery with double the charge rate then most EV tariff.

 

[yessuz]

Apologies in advance if this is already covered (life is to short to read this thread) but to the question of is solar worth it in UK

Going through this exercise now. Due to roof orientation, shading etc the best I can hope for is 3000kWh annually. Now with intelligent Octopus peak rate this would equate to approx £900 savings a year assuming I used it all. But once I stick a battery in the mix and have the ability to power house using off peak, which suddenly makes the so-called savings approx £250 annually, which for a £4-8K PV investment is a payback period of decades.

Outcome: Sod the solar, Slap in a GivEnergy All In One battery and payback in under 7-8 years even taking into consideration the VAT I need to pay for a battery only install

Yes, in theory.

But this suddenly changes once IO rate doubles.

With battery & solar together you at least can be sure that your price on avg will be lower than lowest price of IO. While on battery only you still will average out at somewhat above IO off-peak

 

[tomorrowman]

Yes, in theory.

But this suddenly changes once IO rate doubles.

With battery & solar together you at least can be sure that your price on avg will be lower than lowest price of IO. While on battery only you still will average out at somewhat above IO off-peak

It gets more interesting if you potentially start selling excess battery capacity back at higher rates than you charged but that's very battery dependent. I can see I might have to go '2 battery' as my winter consumption is significantly higher than in summer (primarily due to dehumidifier's running - next project MVHR) plus I'm about to switch from gas to heatpump (and induction hob). Interesting times

 

[Pete UK]

Holy schnitzel! Is this what non solar people have to put up with day to day?

View attachment 961185

We... ran out of solar today. Everyone returned from various camping activities over the weekend so the washer and heated airer has been on double time, and the weather has been atrocious as mentioned, and we are mid swap to Octo and IO so no recharge over night... And the end result is horrible!

Is this normal for the non solar users!? I didnt have a smart meter before the panels so have never experienced a full price day being highlighted to me before. Something shoddy like 6kw from the panels today, battery started empty and we pulled 17kw from the grid.

Please someone bring me the sun back! (Or hopefully get sorted and onto IO soon).

I dropped them an email to confirm if I was on IO on Friday and by Monday it had all happened.

Pre- Solar a lot of winter days I was seeing £27 a day electricity

 

[Pete UK]

bottomed out at 5% overnight and used a bit of grid to keep it there. Slowly topping up now but not sure it'll fill today.

confused as my givenergy settings have a 1:30-6:30 timed charge set to 20% so it shouldn't have dropped below that?

Did you do the recent inverter (battery) software upgrade? Or did it get pushed remotely without you knowing ? Latest is 305, previous was 303. Check in the inverter “software” tab.

If so people on the GE forum were reporting some settings may have been reset during the update process, despite showing set correctly as previously. Check in the inverter settings and re-submit the timed charge setttings (change them by a minute or so and re-submit to confirm and check you get the ‘written to inverter’ green tick flash up on the screen).
Then check in the remote control settings that they show the correct timed charge figures (written to) in the remote control area

 

[yessuz]

I dropped them an email to confirm if I was on IO on Friday and by Monday it had all happened.

Pre- Solar a lot of winter days I was seeing £27 a day electricity

that is mistake. they will not show your rate correctly (at least in my case it is allways BS).

actual bill is correct though.. therefore I always look at the kw of actual consumption

 

[yessuz]

It gets more interesting if you potentially start selling excess battery capacity back at higher rates than you charged but that's very battery dependent. I can see I might have to go '2 battery' as my winter consumption is significantly higher than in summer (primarily due to dehumidifier's running - next project MVHR) plus I'm about to switch from gas to heatpump (and induction hob). Interesting times

it is loss making activity. no one will allow you to sellfor more than IO off-peak rate. only one is Scottish power, but you have to show them schematics that you cannot export from battery, IIRC

 

[Avendit]

that is mistake. they will not show your rate correctly (at least in my case it is allways BS).

actual bill is correct though.. therefore I always look at the kw of actual consumption

Mine shows the bill accurately, but the cumulative KWh figures are either rubbish, or the units are set to Mwh.

 

[Mrklaw]

Did you do the recent inverter (battery) software upgrade? Or did it get pushed remotely without you knowing ? Latest is 305, previous was 303. Check in the inverter “software” tab.

If so people on the GE forum were reporting some settings may have been reset during the update process, despite showing set correctly as previously. Check in the inverter settings and re-submit the timed charge setttings (change them by a minute or so and re-submit to confirm and check you get the ‘written to inverter’ green tick flash up on the screen).
Then check in the remote control settings that they show the correct timed charge figures (written to) in the remote control area

battery is still showing a firmware update is available to 3012. inveter shows its on D0.535-A0.535 and no update available (AC3.0 inveter not hybrid). I’ve tweaked the % and saved, and checked in remote control that it matches. I’ll keep an eye on it

 

[yessuz]

Mine shows the bill accurately, but the cumulative KWh figures are either rubbish, or the units are set to Mwh.

yup.

I think they do not separate the price for peak/off peak in the the "summary screen", and it looks like they show the most expensive tariff all the time.. However if you look at the "current usage" tab, it will actually show you the current consumption and price per hour, which is accurate.

I do not know why it is the case.