Solar panels and battery - any real world reccomendations?

[b0rn2sk8]

I agree, one of my work colleagues paid 30k for a solar edge system with 22 panels and 2 x 10 kWh batteries........

Holy ****!

The other thing that boils my blood is the MCS payback calculation they give you. Anyone who has bought solar in the last 18 months would have had a ludicrous inflation figure used when they calculate the future benefit.

I think one of mine had electric hitting >50p/kwh in the next 5 years, absolutely ridiculous given we all new what was going to happen and has happened (e.g. domestic electric prices have dropped 50% in the last year). I'll be honest I'm not sure how long export rates at 15/16p will actually last when SVR is 'only' 22p.

I bet on the paperwork that £30k system paid back in 10 years, they'll be lucky if it does in 20.

I'll be happy if my system which costs 16k will pay back in 8 years and we are fully electric with a heat pump - no gas at all. We also have an EV but that doesn't impact the payback calculation unless export rates tank to below 7p.

 

[94JDH]

Boils my blood, it really does. That extra money they saved could have went towards something else for the property.

Nice property so assume ability to pay which always isn't the case.

 

[Ron-ski]

I've seen countless videos where they've fitted solaredge, and the installers argument is it's safer, and they can more easily see if there's a problem with a panel. They make it sound like they are always checking customers installations, I wonder just how often they do, probably only if the customer notices something.

 

[Journey]

Nice property so assume ability to pay which always isn't the case.

Indeed, £22k is a hell of a lot of money. It's even more staggeringly bad when you consider the panels they used can be had for £47+VAT to a consumer, not in bulk to a trade user, and even including the not required optimisers it's still under £100 per panel. I bet if they found this out they'd be shocked, hopefully not by the workmanship at that cost though!

 

[maddness]

When I told one reseller you're 5k more than what I've been quoted, they said its impossible and they can't do it at that price and that there are lots of shady installers and will take your money and do a runner lol

I paid after completion with my installers (bar the 10% upfront)

Again all this happened within a week from start to finish

 

[Deep]

Last week I had Sogo Solar come round and give me a quote and design concept.

Option 1
9 Panels from REC and a 10kWh SolarEdge battery
This will potentially generate 2,960kWh/a

Option 2
6 Mayer Burger panels and a 5kWh Enphase battery
This will potentially generate 2,081kWh/a

My consumption is approx. 2,800kWh a year and I'm planning on getting an electric car next year (subject to pay rise)

I'm getting a bit confused with all the numbers around and how to plan how much electric the car will use based on potential mileage. If I get the Skoda Enyaq, I've read it gets about 3.4 miles per kWh. To get a fairer number lets say it get's 2.5 miles per kWh would it potentially use 3,200 kWh over a year if I do 8k miles. Total energy usage will be around 6,000 kWh.
So best case scenario is that I will hopefully only need to buy 2/3 of my electric from the grid?

Is that right or am I being completely stupid?

 

[Gammawolf]

Does the below make sense at all? Estimate to come in around £6k self build.

12x JA Solar 505W Mono PERC Half-Cell (in a 3s2p per controller, 6KW total)
2x Victron MPPT 150/60
16x 280Ah LiFePO4 cell in a 51.2v pack (14.3KWh)
1x JBD BMS Smart 16S LiFePo4 48V 200A
1x Victron Energy MultiPlus-II 48V 10000VA 140A
1x Victron Energy Lynx 1000A Distributor
1x Victron Energy Lynx 1000A Shunt
+various switches/breakers, cabling/terminals, battery enclosure, scaffolding, panel mounts

 

[b0rn2sk8]

Last week I had Sogo Solar come round and give me a quote and design concept.

Option 1
9 Panels from REC and a 10kWh SolarEdge battery
This will potentially generate 2,960kWh/a

Option 2
6 Mayer Burger panels and a 5kWh Enphase battery
This will potentially generate 2,081kWh/a

My consumption is approx. 2,800kWh a year and I'm planning on getting an electric car next year (subject to pay rise)

I'm getting a bit confused with all the numbers around and how to plan how much electric the car will use based on potential mileage. If I get the Skoda Enyaq, I've read it gets about 3.4 miles per kWh. To get a fairer number lets say it get's 2.5 miles per kWh would it potentially use 3,200 kWh over a year if I do 8k miles. Total energy usage will be around 6,000 kWh.
So best case scenario is that I will hopefully only need to buy 2/3 of my electric from the grid?

Is that right or am I being completely stupid?

How much and do you have any shading issues?

A lot of the fixed cost in a solar install is putting the panels on the roof (scaffold, labour) and design overhead. Ideally you want to max out as many panels as you can fit on the roof once. It’s too expensive to go back and add a few more later.

It’s currently cheaper to charge your car overnight on cheap rate electricity, tariffs currently offer 6 hours overnight for 7p/kwh than to charge from solar as suppliers are currently paying 15p/kwh for energy you export during the day.

Think of the grid as as a trading partner, for every KWH you can sell to them during the day, you can buy 2kwh overnight for the same price. You also want to charge up any storage battery overnight when it’s cheap for the same reason - maxing out that export.

Don’t forget, it is possible to have a negative electricity bill which you can use to offset any gas usage and standing charges.

I’d say you were being overly pessimistic on your cars energy usage. Charging losses are usually under 10% so if it achieves 3.4 miles/kwh (looks reasonable to me), you only need to add another 10% onto that. 2.5miles/kwh is very low.

 

[Deep]

How much and do you have any shading issues?

A lot of the fixed cost in a solar install is putting the panels on the roof (scaffold, labour) and design overhead. Ideally you want to max out as many panels as you can fit on the roof once. It’s too expensive to go back and add a few more later.

It’s currently cheaper to charge your car overnight on cheap rate electricity, tariffs currently offer 6 hours overnight for 7p/kwh than to charge from solar as suppliers are currently paying 15p/kwh for energy you export during the day.

Think of the grid as as a trading partner, for every KWH you can sell to them during the day, you can buy 2kwh overnight for the same price. You also want to charge up any storage battery overnight when it’s cheap for the same reason - maxing out that export.

Don’t forget, it is possible to have a negative electricity bill which you can use to offset any gas usage and standing charges.

I’d say you were being overly pessimistic on your cars energy usage. Charging losses are usually under 10% so if it achieves 3.4 miles/kwh (looks reasonable to me), you only need to add another 10% onto that. 2.5miles/kwh is very low.

I just had to confirm whether VAT was included or not turns out they're VAT exempt.
Option 1 is £14,480 (7,943 panels + 6,537 battery)
Option 2 is £10,783 (6,458 panels + 4,325 battery)

Option 1 will max out the panels but option 2 is from an aesthetic stand point. I'm leaning towards maxing out panels anyway.
That's a very interesting point, sell during the day and charge overnight for use the next day.

I think because I've never used an electric car I'm just using the same thing I'd do for ICE cars. They give you an average MPG and it's always in the best case scenario whereas it might not be that bad.

 

[b0rn2sk8]

Both options are pretty expensive IMO.

I noticed you’ve been specced solar edge or enphase products, do you have any issues with shading on your roof?

 

[Deep]

Both options are pretty expensive IMO.

I noticed you’ve been specced solar edge or enphase products, do you have any issues with shading on your roof?

Nope thankfully one roof side (SW) is completely open and the other roof at the front (NW) will also get a lot of late afternoon and evening sun.
I imagine it's expensive but one of the key things is that it's hard to find a legitimate company, there are far too many cowboys and scammy companies out there. Sogo Solar are really recommended and are Which rated which really comforts me.

 

[b0rn2sk8]

I presume they are fitting solar edge or enphase inverters for options 1 or 2?

You may get better advice if you post the full breakdown of what’s being installed.

The Solar Eedge and Enphase ecosystems are quality kit but their USP is that they can seamlessly deal with shading issues and lots of panels facing all different directions on the same string. Installers like it because you can just plug it all in and it works. The downside is it’s expensive, it adds a huge amount of cost.

If you don’t need that functionality, it’s not the best use of cash and it will reduce your ROI.

See mine and others grips with installers who default to solar edge when it just isn’t needed in the previous couple of pages.

 

[Ron-ski]

1x Victron Energy MultiPlus-II 48V 10000VA 140A

I'm at work so not got time to check if all is compatible at the moment, but check that the inverter has the relevant g99 certificate if connecting to the grid, it never use to have, but last time I checked was about a year ago.

Are you using a DIY pre-made battery box?
Any reason not to use the new JK Inverter BMS?

 

[Gammawolf]

I'm at work so not got time to check if all is compatible at the moment, but check that the inverter has the relevant g99 certificate if connecting to the grid, it never use to have, but last time I checked was about a year ago.

Are you using a DIY pre-made battery box?
Any reason not to use the new JK Inverter BMS?

I've not come across a pre-made diy box for packs this size, do you have any links to ones? I was essentially going to diy one with ply and rods for the compression since the only ones I saw were for 12v packs.
No particular reason on the BMS, if the JK is better/more recommended I've no issues using that
For the certificate this should hopefully cover it?

https://www.victronenergy.com/uploa...&-G99-NI-MultiPlus-II-48-8kVA-10kVA-15kVA.pdf

Edit: Seen what you mean from a few videos from off grid garage, EEL V4 JK-48V-Box looks pretty slick

 

[Deep]

I presume they are fitting solar edge or enphase inverters for options 1 or 2?

You may get better advice if you post the full breakdown of what’s being installed.

The Solar Eedge and Enphase ecosystems are quality kit but their USP is that they can seamlessly deal with shading issues and lots of panels facing all different directions on the same string. Installers like it because you can just plug it all in and it works. The downside is it’s expensive, it adds a huge amount of cost.

If you don’t need that functionality, it’s not the best use of cash and it will reduce your ROI.

See mine and others grips with installers who default to solar edge when it just isn’t needed in the previous couple of pages.

Option 1
REC 420W panels
SolarEdge 10kWh battery
SolarEdge Inverter

Option 2
Meyer Burger 385w panels
Enphase inverter
Enphase battery

They haven't gotten down into specific model numbers or anything
Just a nice little summary table and a bit of text

It does feel a bit expensive, but this is planning to be my long term house so perhaps taking the hit isn't that big of an issue.

 

[tamzzy]

It does feel a bit expensive, but this is planning to be my long term house so perhaps taking the hit isn't that big of an issue.

that's not only expensive, that's ridiculously expensive
i had mine fitted in feb, no need for optimisers in my case

10x440w jinko panels
3.6kw sunsynk inverter
1x 5.12kwh sunsynk battery
= £6885 all in, inclusive of scaffolding and bird netting
(and i've since added in another 5.12kwh battery shortly after for £1450, so total damage = £8335)

 

[Journey]

Nope thankfully one roof side (SW) is completely open and the other roof at the front (NW) will also get a lot of late afternoon and evening sun.
I imagine it's expensive but one of the key things is that it's hard to find a legitimate company, there are far too many cowboys and scammy companies out there. Sogo Solar are really recommended and are Which rated which really comforts me.

E.on use GivEnergy and 0% for 3 years and are cheaper.

 

[Ron-ski]

Does the below make sense at all? Estimate to come in around £6k self build.

12x JA Solar 505W Mono PERC Half-Cell (in a 3s2p per controller, 6KW total)
2x Victron MPPT 150/60
16x 280Ah LiFePO4 cell in a 51.2v pack (14.3KWh)
1x JBD BMS Smart 16S LiFePo4 48V 200A
1x Victron Energy MultiPlus-II 48V 10000VA 140A
1x Victron Energy Lynx 1000A Distributor
1x Victron Energy Lynx 1000A Shunt
+various switches/breakers, cabling/terminals, battery enclosure, scaffolding, panel mounts

The MPPT 150/60 is borderline OK for you panels - see here. The reason I say borderline is because at -10c you could exceed 150v which will potentially damaged the MPPT.
You have a distributor listed, these are expensive, and the only benefit is the blown fuse indicator, you can save quite a bit of money and fit fuses to the Lynx Power In.

Thoroughly plan your system before you order anything, also make sure that you're battery is connected via a T Class fuse - Victron do a T class Lynx fuse holder now or use stand alone T class fuse holders - mega fuses don't have the AIC rating for LifePo4.
Don't use a rotary DC isolator like the Victron one, I used one so I could easily isolate the inverter, but pulling 160 amps through it they get extremely hot, if you've multiple batteries they'd be OK on each battery, but I'd not use them and removed mine.

I've not come across a pre-made diy box for packs this size, do you have any links to ones? I was essentially going to diy one with ply and rods for the compression since the only ones I saw were for 12v packs.
No particular reason on the BMS, if the JK is better/more recommended I've no issues using that
For the certificate this should hopefully cover it?

https://www.victronenergy.com/uploa...&-G99-NI-MultiPlus-II-48-8kVA-10kVA-15kVA.pdf

Where have you been, which rock have been under??? There are dozens of 48v boxes, I diy built my batteries but I would not do it now (build thread).

Some examples:

Solar Battery Storage | Fogstar UK

When it comes to solar battery storage, we understand that choosing the right storage solution for your solar energy is crucial, which is why we offer a range of options to suit your installation.

www.fogstar.co.uk

Be aware of these options, features and flaws of DIY Vertical Battery Boxes. A comparison...

In this video, I'll go over features, options, designs and flaws of these vertical batteries we had a look at over the last few videos. It's not a comprehens...

youtu.be

Testing the new EEL V4 48V DIY Box with JK Inverter BMS. Are we there yet???ð«

Many of you wanted me to test out this new V4 EEL 48V DIY Box, so here it is. This is again a trye DIY box which comes with all bits and pieces, so there is ...

youtu.be

The Yixiang DIY Battery Box on the testbench. Does it tick all the boxes?

This was too good to say no to! The Yixiang DIY battery box seems to have all the features we ever wanted from such a case. It has the 200A JK inverter BMS w...

youtu.be

Battery DIY-Kits

On this page, you will find some battery DIY-Kits, I have tested on the channel. These are mainly pre-configured battery cases with all accessories included. It’s a battery construction set w…

off-grid-garage.com

JK Inverter BMS https://youtu.be/eZX7CkEEq_8?si=Wsyl2uqUflEtK4xj - that's quite an old video, there are many others on the Offgrid Garage channel.

Yes that certificate is the right one, and will do the job.

Got to go, got to order parts for my upgrade.

 

[b0rn2sk8]

Option 1
REC 420W panels
SolarEdge 10kWh battery
SolarEdge Inverter

Option 2
Meyer Burger 385w panels
Enphase inverter
Enphase battery

They haven't gotten down into specific model numbers or anything
Just a nice little summary table and a bit of text


It does feel a bit expensive, but this is planning to be my long term house so perhaps taking the hit isn't that big of an issue.

A bit expensive is somewhat an statement, I'd be shopping around. The REC panels are meant to be good but they are expensive at £140 a piece. A 440W Jiko panel is £71 a piece. I'm not sure what the benefit of the Meyer Burger panels are, are expensive and have a lower output - not Chinese?

I'm all for spending money where it makes sense but only if it improves performance and the return on your investment. Hardly anyone puts solar on their house to make them feel good, its all about the economic benefits it brings. The more you spend on the system for the same performance, the less benefits you get so there is no logical sense in taking the hit. This is crucial when you are fitting a small system as you'll still incur a lot of the fixed costs of installation.


Below is the actual equipment costs for option 1, they'll be a lot of sundry costs on this (say at most another £1k of misc. equipment) and an installer will be getting some trade discount. If you add the below up you'll realise you are being charged over £5k for design, installation, scaffolding and warranty. Installation is a one day job for 4 people.
REC 420W panels 9X £117 = £1053
SolarEdge 9.7kWh battery = £4950
SolarEdge Inverter = £900
Solar Edge Optimiser = £465

If you just swapped out the Solar Edge edge kit for say GivEnergy, you'd save £2,800 alone a system with effectively the same performance. A GivEnergy 3.6kw or 5kw hybrid inverter plus 9.5kwh battery = £3500

The only reason I can see of going Solar Edge or Enphase is that you've got such a small number of panels on each side of your roof, it makes sizing an inverter tricky. Perhaps someone else can weigh in on that.

 

[passingthrough]

A bit expensive is somewhat an statement, I'd be shopping around. The REC panels are meant to be good but they are expensive at £140 a piece. A 440W Jiko panel is £71 a piece. I'm not sure what the benefit of the Meyer Burger panels are, are expensive and have a lower output - not Chinese?

I'm all for spending money where it makes sense but only if it improves performance and the return on your investment. Hardly anyone puts solar on their house to make them feel good, its all about the economic benefits it brings. The more you spend on the system for the same performance, the less benefits you get so there is no logical sense in taking the hit. This is crucial when you are fitting a small system as you'll still incur a lot of the fixed costs of installation.


Below is the actual equipment costs for option 1, they'll be a lot of sundry costs on this (say at most another £1k of misc. equipment) and an installer will be getting some trade discount. If you add the below up you'll realise you are being charged over £5k for design, installation, scaffolding and warranty. Installation is a one day job for 4 people.
REC 420W panels 9X £117 = £1053
SolarEdge 9.7kWh battery = £4950
SolarEdge Inverter = £900
Solar Edge Optimiser = £465

If you just swapped out the Solar Edge edge kit for say GivEnergy, you'd save £2,800 alone a system with effectively the same performance. A GivEnergy 3.6kw or 5kw hybrid inverter plus 9.5kwh battery = £3500

The only reason I can see of going Solar Edge or Enphase is that you've got such a small number of panels on each side of your roof, it makes sizing an inverter tricky. Perhaps someone else can weigh in on that.

I would also add here Incase you don't know. Givenergy are giving their EV charger away for free with any 9.5 or AIO purchased in July. I missed out but maybe good for some.