RedMod3
Member
I renew in March next year. I believe the Government will have to do something as the October rates will be unsustainable for consumers and businesses.
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Solar Panels UK - is it worth it?
- Thread starter jdwuk
- Start date
PITA
Model 3 Performance
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No Powerwalls, No Solar and No 'Go' Smart Meters
Just for an Apocalyptic nightmare comparison ...
I suspect the 60/10 will be October (Octo should announce rates in ~10 days then we will know) as you pay more than the capped 52p rate on the over night tariffs. And Jan could be another 20% higher (72p headline), and April potentially another 10-20% higher again~80p.
I'm also happy working on the assumption that unit rates will probably not come back down noticeably, although they might stop increasing for a while, but you might want to check the math if rates drop back to where they are now after a 2 year spike?
Interestingly, looking at your figures, adding solar is always good (or you haven't gone far enough to find where adding more stops contributing?), but on the cheaper rates the ROI on additional PW's tails off pretty quickly. But at the higher rate, when each one saves you £500 it seems a bit of a no-brainer to have as many as you have room for!
Thanks to all of you for your thoughts and points. Things I've learned;
1. I hadn't appreciated the VAT implications of not doing PV and Battery (if your going to do both) at the same time.
2. 7.5p, or anything remotely that low may not last much longer.
3. Point 2 blows my marginal cost of PV theory out of the water, i.e. with a marginal saving re PV of 7.5p vs 0.0p the payback period of a PV array would be very long, based on my annual usage (3,400 kWh, pre the arrival next month of my M3P). I only do circa 6k miles per annum, nearly all within battery range, so charging will nearly all be at home. I've estimated, allowing for 12% charging losses, and 0.9% vampire drain, an annual consumption of 2,062 kWh for the M3P. Assuming I can resist the temptation to accelerate too hard! Does this sound reasonable?
I'm still on a fixed deal until 31 Aug next year (Elec 20.66p, Gas 3.99p). So I have time to get things right, and I don't want to lose the Gas part of my dual fuel deal early, as this could (would) probably wipe out any electricity savings in the next 12 months, if I were to switch provider.
I thought I was going into too much detail when trying to work out the cost / benefit of solar, but having read this thread I realise I'm an amateur! I'm still re-reading and digesting your posts about what I thought was a straight forward calculation, at the start! I now realise that the more you delve into it the complicated it is.
What doesn't help is the extreme market volatility at the moment, combined with a mute government!
I've got a company coming (Powerwall authorised) to give me some quotes in 2 weeks time, any advice re the right questions to ask would be appreciated.
Thanks again.
1. I hadn't appreciated the VAT implications of not doing PV and Battery (if your going to do both) at the same time.
2. 7.5p, or anything remotely that low may not last much longer.
3. Point 2 blows my marginal cost of PV theory out of the water, i.e. with a marginal saving re PV of 7.5p vs 0.0p the payback period of a PV array would be very long, based on my annual usage (3,400 kWh, pre the arrival next month of my M3P). I only do circa 6k miles per annum, nearly all within battery range, so charging will nearly all be at home. I've estimated, allowing for 12% charging losses, and 0.9% vampire drain, an annual consumption of 2,062 kWh for the M3P. Assuming I can resist the temptation to accelerate too hard! Does this sound reasonable?
I'm still on a fixed deal until 31 Aug next year (Elec 20.66p, Gas 3.99p). So I have time to get things right, and I don't want to lose the Gas part of my dual fuel deal early, as this could (would) probably wipe out any electricity savings in the next 12 months, if I were to switch provider.
I thought I was going into too much detail when trying to work out the cost / benefit of solar, but having read this thread I realise I'm an amateur! I'm still re-reading and digesting your posts about what I thought was a straight forward calculation, at the start! I now realise that the more you delve into it the complicated it is.
What doesn't help is the extreme market volatility at the moment, combined with a mute government!
I've got a company coming (Powerwall authorised) to give me some quotes in 2 weeks time, any advice re the right questions to ask would be appreciated.
Thanks again.
Rooster6655
Active Member
Let’s assume a house with an EV you will consume an average of 20kWh a day. If you were to get 2 x 9.5kWh batteries installed it’s likely to be around £12k based on a price I saw quoted, that’s £2k in VAT. So most definitely worth looking at a small solar setup at the same time, as it’s like £2k going towards it.
The ROI on a solar array will vary depending on a variety of things, when working out how long something will take to pay back, it will depend on what you are comparing it to, I think comparing to what you can buy the electric at if stored is a fair comparison
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RedMod3
Member
I ordered 3 PWs and had 4 extra panels added to get 0% VAT and today, the panels have brought in 1MWh since installed in March. However, not going to get an extra 8 panels as the ROI is good.
Rooster6655
Active Member
sorry, can you explain this? i don't understand how this works, especially starting earlier and carrying on later
thanks
This is a (theoretical rather than specific) inverter efficiency curve:
Its using % along the bottom. In my previous situation, when 100% = 8kw, but I only actually have 4.1kw facing the sun at any one time. On a cloudy day I was only outputting ~400w. 400/8000 is in the 5% range on that graph, and the inverter is only running at 70% efficiency or less - throwing away lots of power.
Now think of the times the panels are outputting low energies - dull days. Winter days. Early morning and late evening. All of these happen lots, especially up in scotland, and in each case I'm losing 30% or more of my output. And all to cover the 3 days a year where I can max everything out.
Basically, by having an inverter set to the right, or slightly under, your theoretical peak, you maximise the output at lots of other times of the year, and these marginal gains add up way more than the potential loss of 0.25kwh from 12pm on the brightest 3 days of the year.
As a graph it looks like this:
and basically you are taking the safe bet that in the UK the extra area under the dark red line, which in guaranteed to happen every day, adds up to more than the little blip at the top where you have maxed your inverter and are now clipping. Up in scotland, even in July I had entire days live in that low output area, and my array output 1/3rd of what it should have. Got a more closely matched inverter (having a split system complicated all this of course) and almost doubled my cloudy day output as I was living so far down than performance trough from the first graph.
Hope that helps a little?
Its using % along the bottom. In my previous situation, when 100% = 8kw, but I only actually have 4.1kw facing the sun at any one time. On a cloudy day I was only outputting ~400w. 400/8000 is in the 5% range on that graph, and the inverter is only running at 70% efficiency or less - throwing away lots of power.
Now think of the times the panels are outputting low energies - dull days. Winter days. Early morning and late evening. All of these happen lots, especially up in scotland, and in each case I'm losing 30% or more of my output. And all to cover the 3 days a year where I can max everything out.
Basically, by having an inverter set to the right, or slightly under, your theoretical peak, you maximise the output at lots of other times of the year, and these marginal gains add up way more than the potential loss of 0.25kwh from 12pm on the brightest 3 days of the year.
As a graph it looks like this:
and basically you are taking the safe bet that in the UK the extra area under the dark red line, which in guaranteed to happen every day, adds up to more than the little blip at the top where you have maxed your inverter and are now clipping. Up in scotland, even in July I had entire days live in that low output area, and my array output 1/3rd of what it should have. Got a more closely matched inverter (having a split system complicated all this of course) and almost doubled my cloudy day output as I was living so far down than performance trough from the first graph.
Hope that helps a little?
RedMod3
Member
Yes, with 2 PWs, I've not used peak power for months. At the moment, I'm only topping up my PWs on alternate nights while we have lots of sun. Its 22:20, at the PWs are at 66%, so PWs will not be charged tonight as we are expecting good sun tomorrow.
Just wondering if anyone has had experience of Fox hybrid converters and batteries? One of the PV installers that I am getting a quote from uses them:
Thanks in advance.
Fox Hybrid & AC Charger | Solar Inverter | UPS Solar
Fox Hybrid & AC Charger. Contact us for more Solar Panels , Battery and solar edge and hybrid inverters from high quality brands.
ups-solar.co.uk
Fox Energy Cube| Solar Inverter | UPS Solar
Fox Energy Cube - Fox HV2600. Contact us for more Solar Panels , Battery and solar edge and hybrid inverters from high quality brands.
ups-solar.co.uk
Thanks in advance.
FoxESS are part of the Chinese Tsingshan Group, the largest producer of stainless steel in the world who are now moving into Solar. The app doesn’t get good reviews on the Apple App Store if that matters. In terms of UPS Solar while they generally have good reviews, I’m still waiting for them to call me back (missed their original call). Guess they are snowed under but not a good start compared to other companies.
My friend next door got a quote this morning so am trying to piggy back onto that
thanks for the info and am unsure about the Fox stuff and am also looking at GivEnergy as well…
On the plus side GivEnergy are UK owned though I think there stuff is made in China. They seem a lot more common than FoxESS, at least in the UK and they seem to have sorted out the 5 minute refresh on their app as now pretty much instant if on the same Wi-Fi network (think it’s still 5 minutes if away from home) - there‘s a good review of the app here GivEnergy app. Also worth checking out this installation video though some bits are quite technical as from the installers point of view GivEnergy installation
Just had my system fitted and it’s been running for the past couple of days.
It’s a 3.6kw system (9 X Trina Vertex S 400) with a 4.8kWh battery (2 x Pylon 2.4kwh US2000 C Li-ion). Compared to most systems on here this may seem on the small side but our usage is fairly low, like.. 4-5kWh a day when not charging.
So far it’s been running great, my biggest issue is generating more power than needed so some of it has been going to the grid. I’m on octopus Go so once I get the paperwork I can sign up to SEG. These batteries are daisy chained so I could add a third in future (we’ll see).
I haven’t needed to charge the battery from Go’s off peak because the panels usually have it charged by midday, I will probably need to adjust it in the winter though. Annoyingly I use the Solis inverter which doesn’t allow you to make these changes from the app (the app is basically read-only) so any settings need to be changed on the inverter itself which means trips into the loft every now and then.
Ideally I would like to have excess go to the car though but I use Wallbox Pulsar, so I’m handling this manually at the moment which isn’t ideal. Anyone with wallbox set this up? I believe they offer the eco smart but looks like a module which needs to be installed on the CU.
Anyway glad I did it, looks like it’s been a solid investment.
It’s a 3.6kw system (9 X Trina Vertex S 400) with a 4.8kWh battery (2 x Pylon 2.4kwh US2000 C Li-ion). Compared to most systems on here this may seem on the small side but our usage is fairly low, like.. 4-5kWh a day when not charging.
So far it’s been running great, my biggest issue is generating more power than needed so some of it has been going to the grid. I’m on octopus Go so once I get the paperwork I can sign up to SEG. These batteries are daisy chained so I could add a third in future (we’ll see).
I haven’t needed to charge the battery from Go’s off peak because the panels usually have it charged by midday, I will probably need to adjust it in the winter though. Annoyingly I use the Solis inverter which doesn’t allow you to make these changes from the app (the app is basically read-only) so any settings need to be changed on the inverter itself which means trips into the loft every now and then.
Ideally I would like to have excess go to the car though but I use Wallbox Pulsar, so I’m handling this manually at the moment which isn’t ideal. Anyone with wallbox set this up? I believe they offer the eco smart but looks like a module which needs to be installed on the CU.
Anyway glad I did it, looks like it’s been a solid investment.
Zilla91
Active Member
Does anyone have Canadian Solar panels? Been recommended them to go with a 9.5kwh GivEnergy battery and hybrid inverter.
I ordered a GivEnergy hybrid inverter and 9.5kWh battery earlier this summer (with panels, not Canadian). Kit was delivered this week for installation next week - but they swapped out GivEnergy for other brand. I haven’t decided how to resolve that yet - but be aware the feedback they gave so far was that the 5kW Gen2 hybrid inverter and 9.5kWh battery are unavailable across UK right now.
GivEnergy gen 2 kit is in the UK now but supply is very tight. The suggestion is that wholesalers have over-sold and are potentially rationing supply with a preference for some suppliers. However this is all conjecture. GivEnergy themselves are tight-lipped other than to acknowledge supply chain issues. However, there are shortages across the board it would appear. I've ordered Giv gear and am "promised" an install late in October - we'll see! At least I'm in the queue which is now very long! One of the other guys on here also had his Giv install pushed to early October from this week, again due to supply issues.
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