Solar panels and battery - any real world recommendations?

To be fairness artisan was largely vindicated in that video. The DNO messed up, they gave a 15kw export limit instead of 5kw, that is quite the error.

You’d not have installed the system they did if you only had a 5kw export limit.

The DNO took the hit upgrading them to 3 phase with 5kw export per phase which is an appropriate export limit given their location.

He was rightly criticised for the voltage optimiser, that was very bodge and didn’t fix the issue.

He still comes across as a smug know it all on camera though.

As for the install above, I don’t think anyone it criticising what was installed. It’s the price heatable charges just mad. Yes I know he got it for a lot less due to the social media exposure but the point is a local installer would have installed an equivalent system for significantly less money.
 
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94JDH said:
Yes, this house was costing him something like £30 per day because of electric radiators.
Also his explanation of the available PV power and his "paralleled system" wasn't great as there was no mention of the ability to to improve each 5 kW hybrid inverter's throughput by charging at the same time as his max use/export maximising the potential of the oversized array.


Jordan always critical, expensive & made a dog's ear of the large install on an unused tennis court blaming the over and under voltage on the DNO. Another YouTuber who's an electrician amusingly ripped him apart.
Fortunately for Jordan, probably due to his visibility, the DNO have got him out of the situation by upgrading the local transformer (also after criticising them I must add!).
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Not sure if you saw the follow up.
The DNO admitted fault, they issued an incorrect (and too high) export limit.
Paperwork error in effect.

They didn't upgrade the transformer they installed 3 phase in the property.

So not Jordans fault, although the export limit looked dubious it was probably not in his interests to query it ;)
 
Mercenary Keyboard Warrior said:
Not sure if you saw the follow up.
The DNO admitted fault, they issued an incorrect (and too high) export limit.
Paperwork error in effect.

They didn't upgrade the transformer they installed 3 phase in the property.

So not Jordans fault, although the export limit looked dubious it was probably not in his interests to query it ;)
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Yes, the export limit is apparently an up to and with that size of array the output was likely to be a prolonged high output for a sustained period - so probably errors on both sides.
A classic error that they eluded to was using an expensive optimiser to try and resolve the problem (which Jordan always was against until he wasn't!). This caused a secondary problem, which an experienced electrician should have thought about straight away - charging batteries and EV at night caused an under voltage due to the high demand.
 
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Home Assistant beginners

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SkyTerran said:
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disagree with his modelling, he should've reduced the solar growth based on the maintenance cost, rather than meddling with the savings line
the graph would've looked drastically different at 25 years if he did that (yes you'd still be saving money, but not as much as he describes)
 
There's other issues with the working out there too, like the double counting of inflation. He reduced the investment growth by inflation, but then subtracted the electricity cost with inflation added on too. That's counting inflation twice. Considering that makes a £20k difference, it's pretty significant.

Unfortunately it's not the first video of his I've seen with significant errors either, so while he seems like a nice chap, his content is of somewhat questionable reliability IMHO.
 
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Hes ok for the basic stuff when your at the start of your understanding solar journey, if you want to do/know more than simply asking an installer to pick some stuff for you and install it.

The problem gary has like every other solar/renewable youtuber is that they need to keep churning out content and run out of stuff worth producing very quickly.
So they start dreaming up stuff to try to generate new content.

Like his was I wrong about charging batteries over night recent vid.

The simple thing is, your making a multi year payback purchasing decision, unless its purely for going green then your financials are luck.
You can do the obvious things like changing tariffs, moving suppliers etc based on current import/export rates, but above that there isn't much more you can do.
Things like charging batteries, optimising export, diverting to car/water etc all move based on other factors, and will continue to every single year.

Is solar an ok investment, right now sure, but the payback would go waaay out for many if elec prices suddenly halved and export rates suddenly halved.
 
b0rn2sk8 said:
To be fairness artisan was largely vindicated in that video
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I disagree, he really should have known better given the location, and clearly something wasn't correct with the inverter settings, as it should have reduced/cut out and not pushed the voltage so high.

I'm an a DIYer, not a so called professional and I knew that the DNO had made a mistake, why didn't Artisan, and why was those voltages allowed to go so high?

As for that optimiser, a total disregard for neighbours regarding what voltage they got. He setup a system capable of of pulling more than 100 amps from the grid when combined with the car charger and house load.
 
DarkBahamut said:
There's other issues with the working out there too, like the double counting of inflation. He reduced the investment growth by inflation, but then subtracted the electricity cost with inflation added on too. That's counting inflation twice. Considering that makes a £20k difference, it's pretty significant.

Unfortunately it's not the first video of his I've seen with significant errors either, so while he seems like a nice chap, his content is of somewhat questionable reliability IMHO.
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He's uploaded another video, I've no idea if it now contains any serious errors though, and I didn't see the first video.

 
So I've done some reading and talking to companies, but would appreciate if someone could do a sense check for me, just to highight anything significantly wrong with or any suggestions to change the system I'm looking at getting?

Situation:
- We consume 8000 kWh per year
- Working from home, so it's a failry constant draw during the day.
- house is almost due south facing

System ~7000W
- 8 panels on the house roof (450W or 510W, depending of final measurements)
- 6 panels on a flat roof using Van Der Valk frames (510W) on separate string.
- 10 kWh of battery (Fox or EcoFlow)
- EV charger (probably Zappi)
- Octopus "Go" tariff

Installed cost, including scaffolding is going to be in the range of £12,500

10kWh battery seems to be the sweet spot of buying cheap overnight electric to use during winter, and selling surplus electric over summer.
We decided against the Tesla Powerwall or SigEnergy as I don't think we'll make any significant use of the off-grid features.
 
Littlenose said:
So I've done some reading and talking to companies, but would appreciate if someone could do a sense check for me, just to highight anything significantly wrong with or any suggestions to change the system I'm looking at getting?

Situation:
- We consume 8000 kWh per year
- Working from home, so it's a failry constant draw during the day.
- house is almost due south facing

System ~7000W
- 8 panels on the house roof (450W or 510W, depending of final measurements)
- 6 panels on a flat roof using Van Der Valk frames (510W) on separate string.
- 10 kWh of battery (Fox or EcoFlow)
- EV charger (probably Zappi)
- Octopus "Go" tariff

Installed cost, including scaffolding is going to be in the range of £12,500

10kWh battery seems to be the sweet spot of buying cheap overnight electric to use during winter, and selling surplus electric over summer.
We decided against the Tesla Powerwall or SigEnergy as I don't think we'll make any significant use of the off-grid features.
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Can you not fit more panels on your roof? You should be aiming to get as many panels as will physically fit - they are the cheapest part of the system and will likely be costing less than the scaffolding and roofing charges to fit them. Even if you can only get one or two more on, you should maximise it.

Your usage of 8000kWh per year indicates you'll be using an average of 22kWh per day, so your batteries are going to fall a long way short in the winter. I made the mistake of having ~50% of my daily usage as batteries and it was a big mistake (that I will hopefully rectify soon!). If your batteries are only covering 9kWh of the daily use and assuming you only use ~4kWh overnight during the cheap rate, your daily costs will be £1.04 on the nominal 8p rate and then £2.43 on the peak rate for a total of £3.47/day. If you had 25kWh of battery you would only be paying £1.76, saving you £1.71/day. A very quick search suggests it would cost £3300 extra to go up to 25kWh from 10, so realistically probably a 10 year ROI but you'd bring that down considerably with smart exporting in the summer months eg exporting that extra 15kWh each day would make you £2.25/day in the sunnier months. If you just took an average of the two of those things (which is a bit lazy but gives a reasonable approximation) you're £2/day better off having the extra 15kWh, which makes the ROI 4.52 years on a thing with a 10 year life.
 
DRZ said:
Can you not fit more panels on your roof? You should be aiming to get as many panels as will physically fit - they are the cheapest part of the system and will likely be costing less than the scaffolding and roofing charges to fit them. Even if you can only get one or two more on, you should maximise it.

Your usage of 8000kWh per year indicates you'll be using an average of 22kWh per day, so your batteries are going to fall a long way short in the winter. I made the mistake of having ~50% of my daily usage as batteries and it was a big mistake (that I will hopefully rectify soon!). If your batteries are only covering 9kWh of the daily use and assuming you only use ~4kWh overnight during the cheap rate, your daily costs will be £1.04 on the nominal 8p rate and then £2.43 on the peak rate for a total of £3.47/day. If you had 25kWh of battery you would only be paying £1.76, saving you £1.71/day. A very quick search suggests it would cost £3300 extra to go up to 25kWh from 10, so realistically probably a 10 year ROI but you'd bring that down considerably with smart exporting in the summer months eg exporting that extra 15kWh each day would make you £2.25/day in the sunnier months. If you just took an average of the two of those things (which is a bit lazy but gives a reasonable approximation) you're £2/day better off having the extra 15kWh, which makes the ROI 4.52 years on a thing with a 10 year life.
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If it's the Fox battery, you can get another EP11-H for £2000+VAT so it's a no-brainer for him to go for two and have 20kWh, especially at 8000kWh usage per year.

Main things i would say:

- Max out number of panels on all roofs (even northerly aspects)
- Get the biggest inverter possible
- Enough storage to more or less cover a winter day
 
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Just a note to be careful in oversizing the battery. It seems to make sense but thats based on 15p exporting and thats far from a given.
Its a gamble rather than a decision based on certainty thats what you need to consider.
Right now the gamble leads to larger capacity.

You need to consider also, that solar obviously varies a lot in generation.
You will get winter days when you may get 1kWh from your system, but other days a half decent amount. Eg my 5.6kwp system facing East (which is noticeably worse in dead winter) my generation varied from 0.3kWh to 5.5kWh in Dec, you would probably practically double those with South facing and the extra panels your looking at.
Dec is the worst month, Jan and Nov will be bad, Feb and October highly variable but the other seven months with a 7kwp system facing south you aren't going to get that many days where you will have much import.

Times have changed but when I looked into batteries and bought my system I downloaded some other guys data. I played a min max type of thing with the generation and pricing etc (its changed since then) and I found the sweet spot for batteries was in the 75-80% region.
This was without forced exporting though.

You dont mention inverter brand, this can make a difference in how easy it is to min max. Eg until recently it was an absolute pain on Solax, but if your inverter can run the TOU option then you can set more control points to import and export.
 
I agree with what others have said above but with some caveats:

If you have an EV deduct your EV charging from that 8000kwh per year. I assume this to be the case if you have or are getting a Zappi.

If you have a heat pump, don’t try and cover your maximum daily consumption, that’s a silly game to play. There are other tariffs like Octopus Cosy which are far more cost effective to use in December and January than adding more batteries.

I use about 8000kwh per year, I have 10kwp of solar panels split east/west (30% less generation than south, about 50% less in winter specifically) and I ‘only’ have a 13.5 kwh battery.

I have a heat pump and an EV which is why my usage is high but as I seldom use peak time electricity. When I do that’s only in December and January and in those months my average import cost was still under 10p/kwh. It never going to be worth me spending any money on more batteries.

TLDR, you need to put some thought into sizing batteries. More is not better, once you have ‘enough’, adding more extends your pay back period rather than reducing it.

Fit as many solar panels as you can, adding more almost always reduces your pay back period, even north facing panels.
 
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I'm thinking of joining the solar soul train and would appreciate your advice :)

I plan to get a Tesla Powerwall 3 and some panels for a start. My home is a terrace house, that makes a turn half way trough. So I have 4 roof sections. One South facing with room for 6 panels, South-West for 5, North-East for 3 and North for 4.

Initially I thought of getting 14 panels on the South, South-West and North-East parts and leaving the North empty, but I've been reading this thread and people seem to recommend to get panels on the whole roof.

But the problem is the Powerwall in UK comes with 3 solar string inputs, so I won't be able to connect all 4 sections of my roof to different ports.

Do you think I should just get 14, or go for 18? If I do go for 18, how can I connect them to the Powerwall 3? I was thinking maybe get the panels on one of the sections fitted with micro-inverters and connect them to the AC part of the powerwall, but not sure if that is possible and makes sense.
 
The Powerwall 3 is expensive and unless you have a particular desire for whole home back up on the case of a power outage, you’ll get more for your money elsewhere.

Don’t get me wrong, it’s a good product, it’s just expensive. If you have your mind set on it, there is no reason not to go for it but there are better value options if cost is an issue.

You can get hybrid inverters with 3+ inputs now and GivEnergy are also bringing out a Power Wall clone with 6 inputs.

Get all your roof done if you can. You don’t need to use micro inverters if you don’t have enough inputs. You can use a standard string inverter which should also be slightly cheaper and MUCH easier to replace when it comes to the end of its life in 10-15 years time.
 
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