Solar panels and battery - any real world recommendations?

Ron-ski said:
Number one is what I went with, easier to adjust them, easier to mount one at a time, and stronger overall mounting. I made a jig for drilling the mounting holes to space the brackets correctly.

I had thought about cross bracing with perhaps solar PV rail (this would push the panels further away from the wall) or a length of aluminium angle, and also make it more difficult to adjust them due to the weight.

Cross bracing would likely be more expensive than an extra set of adjustable brackets, and if you used one adjustable mount between two panels you'd need something to mount both to the bracket, sort of back to a cross brace.
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That's what I was thinking of doing, getting some batton laid down on the floor and mocking up the panels/brackets on to the batton. Marking the holes, drilling them out and then use that to transfer the layout to the wall. Much easier when you're up a ladder to hold a template out and drill. No messing.

OK, I'll go with option 1 as well then. Seems the most sensible approach with regards to the support and adjustment side of things.


Quick question as I have you... cable sizing. I have 6 panels on an 18 metre run, I'm thinking the 2 core PV Ultra 4mm cable is going to be sufficient using say these DMEGC 450w panels as a guide and running it through various calculators. Most of them recommend 16AWG which feels a bit anaemic to me.
 
Tinders said:
I’ve got a 3 storey Victorian house along with a flat roof extension. Can solar panels be mounted on the flat roof, or does it have to be on the roof of the house? We get sun in the garden for most of the day. Getting panels on the roof would mean maintenance is likely to mean scaffolding everytime.
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Is the roof in good condition?
I would be getting it fixed/recovered if its not been recently done.
Would be a bit of a ballache to get solar fitted then need to redo the roof.

BUDFORCE said:
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Did yesterdays look ok?
And back in time a bit?
 
randal said:
Quick question as I have you... cable sizing. I have 6 panels on an 18 metre run, I'm thinking the 2 core PV Ultra 4mm cable is going to be sufficient using say these DMEGC 450w panels as a guide and running it through various calculators. Most of them recommend 16AWG which feels a bit anaemic to me.
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Use this calculator, aim for below 1% voltage drop, but a bit over will be fine. It has a traffic light system, so easy to know you're OK.

Midsummer Energy

midsummerenergy.co.uk midsummerenergy.co.uk

I'm guessing the six panels will be in series, so 4mm should be fine.
 
Mercenary Keyboard Warrior said:
Did yesterdays look ok?
And back in time a bit?
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No,

Pretty high yesterday and the day before, just about hitting 260v several times but hovering around 250-255.

In fact looking back about a week its generally quite high, it "dipped" down to 238v volts once in the past week, but I would say average its about 250/255v

But today in particular over the afternoon it was consistently a bit higher than it has been enough to trip the safety devices on the solar equipment I guess.

It doesnt surprise me though, like the guy said, we are literally surrounded by wind turbines here, we live in a small village but there are about, 20 or so council houses down the road, and the council recently put solar panels on every single one, that was probably enough to put it out of balance.
 
Mr.Cookie said:
@BUDFORCE Guessing your quite close to the transformer I see 255 260 quite often when voltage checking appliances, our induction hobs don't seem to suffer what make is yours?
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Indesit VIA640C

It's 14 years old, we got it from a Hotpoint factory outlet, it had been returned, but clearly nothing wrong with it.

I've tested it this morning and it's working fine, so was definitely the voltage it didn't like, we were getting 260v+ yesterday, the solar equipment stops reading it at 264v.

It's a bit beat up after all these years, I've smashed the edges in a few places which I've fixed with super glue and baking soda.

We need a new kitchen as that is 25 years old, oven is good knows how old, old, that was a hand me down, so we will replace it in the next few years, just need to save some money.
 
I have a Tesla Powerwall 3 and I'm considering buying 16 solar panels. Wonder if it's a good idea to order these online and get installation arranged separately, instead of buying a package including everything from a company like Heatable or Spectra?

Also it looks like the best panels currently are AIKO Neostar 3N+78 - any idea where to buy those?
 
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@SkyTerran just make sure you find a sparky that will fit those first, before buying the panels.
Most if not all PV fitters will want to provide the equipment and install them (because, more margin)
Also make sure that sparky will provide MCS certificate so you can export.
No MCS= lot of hoops to jump through to export, I think only octopus will accept non-mcs systems.
 
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In all honesty, you are best of finding a local installer who will supply and fit due to all the grief with MCS paperwork.

Most installers are not short of work and are unlikely to take on a partial job with lower margins. They’d sooner rather supply a full system to someone which they can apply a mark up to.

Who installed your Powerwall 3?

The issue you’ll have is that a random installer probably isn’t going to know what to do with that or have access to the installer tools needed to commission solar on it and you are not going to want a separate solar string inverter as you’ll be giving up one of the main benefits of having a power wall 3 over the 2.

Really you are down to those who are Power wall installers and that is a pretty small pool.

Don’t go with heatable, that will be very expensive.
 
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As far as panels go, most installers will do what you want if it’s something specific, as long as their wholesalers have it. AIKO is widely carried isn’t it?

Personally I wouldn’t overpay for a specific panel, not when good quality panels can be had for £60 these days.

Get some quotes and go from there.
 
In the total scheme of things if I pay extra say £2000 for more efficient panels, it won't matter much. Still I'll pay a lot more for the installation, certification, setup, etc.

@b0rn2sk8 Do you mean that to have solar panels working directly with the DC inputs on the Powerwall 3 one has to have a Tesla installer account? So I can't say DIY a few panels on my garage and connect them to the Tesla?
 
SkyTerran said:
In the total scheme of things if I pay extra say £2000 for more efficient panels, it won't matter much. Still I'll pay a lot more for the installation, certification, setup, etc.
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Even if the panels are more efficient, it won't be by much (not seen the specs, so just speculating)
Your ROI time will be massively increased though

b0rn2sk8 said:
Personally I wouldn’t overpay for a specific panel, not when good quality panels can be had for £60 these days.
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This
 
You'll never make back over the lifetime of the panels the extra outlay for those AIKO. Its not like the discussion we had re 390w vs 450w panels, the AIKO are a lot more expensive than cheaper ones and the efficiency is hardly any different, like 0.5-1%.
 
SkyTerran said:
In the total scheme of things if I pay extra say £2000 for more efficient panels, it won't matter much. Still I'll pay a lot more for the installation, certification, setup, etc.
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£2000 is a hell of a lot of export to make up when you are only taking about a few W’s per panel.

I’m not sure you would ever see your money back at that kind of additional spend, not in any reasonable timeframe anyway.

You’d need to generate an additional 13.3mwh to make that up. That’s 1.5X my annual generation from a 10kwp east/west system.

I would get some quotes before making any firm decisions.

SkyTerran said:
@b0rn2sk8 Do you mean that to have solar panels working directly with the DC inputs on the Powerwall 3 one has to have a Tesla installer account? So I can't say DIY a few panels on my garage and connect them to the Tesla?
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I can’t be 100% sure but I doubt it.

Most ‘big brand’ systems you need to be a registered installer to access the installer level settings. To be a registered installer you have to have done their training etc. A quick google suggests you’ll not have access on a Tesla system.

Got a system to work with UK regs, the installer settings shouldn’t be accessible to the end user. It’s exactly the same on say GivEnergy and others.

Sure some brands installer passwords have leaked but the ‘big brands’ use a managed account system which is much harder to bypass.

Basically you need to actually know someone who is a registered installer to get access to it. Even then on say GivEnergy, an installer can only manage the systems they actually installed. You have to take over the ownership of supporting any system you work on if you didn’t install it.
 
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I would add to the above "its not worth it view" to also add you really should not assume export will continue at a decent payment, or even basically at all.

Some countries have started penalising domestic level export as it creates issues for local grids and they prefer the larger managed estates.

There is a curve that is a template but I forget the name for the expected impact on pricing and export potential.

Eg the NL are adding a fee to small scale generators. They are also getting rid of net metering.
In Aus, there is a charge for exporting too much at peak times.
 
I want solar panels because they are good for the environment and it's quite cool to produce electricity for my EV and home.

But from financial perspective I don't think it makes sense to invest 6, 7 or 8K and make back a few pounds on a good day.

I'm sure if one puts the money into a shares ISA he'll have far better returns.

In a recent YouTube video Heatable said pretty much the same thing - asking what's the return of money spend on a car or a holiday, so why are people asking about returns on a solar system.

 
SkyTerran said:
I want solar panels because they are good for the environment and it's quite cool to produce electricity for my EV and home.

But from financial perspective I don't think it makes sense to invest 6, 7 or 8K and make back a few pounds on a good day.

I'm sure if one puts the money into a shares ISA he'll have far better returns.
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We are all with you on that, what we are saying is that when comparing different systems is that ‘value’ is something that you should absolutely be factoring in.

Don’t forget next year, they’ll have an even better panel, the year after that the same again. Pass on 10 years and the panels on your roof will be considered obsolete just like those fitted 10 years ago are now.

It will get to a point, probably after 10 years or so where it will absolutely make financial sense to rip off my perfectly good panels and replace them with the latest generation panels. Except you’ll not be able to do what because your old ones have not yet paid for themselves yet.

SkyTerran said:
In a recent YouTube video Heatable said pretty much the same thing - asking what's the return of money spend on a car or a holiday, so why are people asking about returns on a solar system.
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The issue with anything the likes of Heatable put out is everything they put out online is marketing their own (overpriced) services.

You really do have to apply the appropriate amount of salt to anything any installer says.
 
SkyTerran said:
I want solar panels because they are good for the environment and it's quite cool to produce electricity for my EV and home.
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Thing is the 'cheaper' panels don't change that, they will do almost exactly the same thing as those AIKOs.

SkyTerran said:
But from financial perspective I don't think it makes sense to invest 6, 7 or 8K and make back a few pounds on a good day.
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It absolutely makes sense. I suggest doing some sums on the annual return in percentage terms. Its very comparable to the stock market with considerably less volatility.
 
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