Adding panels myself? (Inverter & cables already installed!)

[glock339]

I've just had what was supposed to be a 35 panel 15kw system installed, however 10 panels were not installed due to a power line being close to one side of a roof.

 

So I have everything already set up for a system with 10 panels more than what I actually have, the cables that were meant to go to the omitted 10 panel string are connected to the inverter & rolled up in the loft ready to go.

 

Next year I will be completely re-doing the garden (which is currently a building site) so was wondering if I build a shed or pergoda etc to take maybe 6 to 8 panels (exact same models as existing obviously) would I be able to do most/all of the work myself or is there still a lot of red tape/certs etc involved in what seems like a fairly simple job? Or are there any other things I should be aware of as well?

 

Cheers.

Edited November 22, 2023 by glock339

[Alan Ambrose]

Physical fixing is fairly easy for someone reasonably DIYish. As is pulling the cable wherever it needs to go - but check with a proper sparky exactly where and how. They're probably the more time consuming (and therefore costly) jobs.

 

A bunch of panels wired together is a decent DC voltage (approx open circuit voltage is # panels x 40V i.e. 400V for 10 panels). And DC is fairly dangerous.

 

The regs say that you need a proper sparky for this kind of work. Theoretically an MCS one if you want to sell back to the grid.

 

Can you not get the original guys back to do you a cheap deal given they didn't install all the panels you expected first time round? They should have known about the power line in advance of course.

[Dillsue]

4 hours ago, glock339 said:

would I be able to do most/all of the work myself or is there still a lot of red tape/certs etc involved in what seems like a fairly simple job? Or are there any other things I should be aware of as well?

Assuming the original installer notified/applied to your DNO, then the only red tape/certs you need to bother with are getting a part P spark to check the wiring before you connect it to the inverter. You can install it all and just get your spark to check it if that's what you want.

 

You don't say whether the coiled up cables are connected to the inverter via an isolator? If they are connected directly just be aware that they may be live with several hundred volts on them depending on how things are wired. If there's no isolator you might want to get one fitted before you start working with the coiled cables.

[glock339]

15 hours ago, Dillsue said:

Assuming the original installer notified/applied to your DNO, then the only red tape/certs you need to bother with are getting a part P spark to check the wiring before you connect it to the inverter. You can install it all and just get your spark to check it if that's what you want.

 

You don't say whether the coiled up cables are connected to the inverter via an isolator? If they are connected directly just be aware that they may be live with several hundred volts on them depending on how things are wired. If there's no isolator you might want to get one fitted before you start working with the coiled cables.

 

Yes I paid the DNO for approval of a 15.575kW system so hoping this still stands, might there be a time limit etc on this approval?

 

Yes they installed DC isolators for each of the 4 string & the unused string isolator is turned OFF.

 

[glock339]

18 hours ago, Alan Ambrose said:

Physical fixing is fairly easy for someone reasonably DIYish. As is pulling the cable wherever it needs to go - but check with a proper sparky exactly where and how. They're probably the more time consuming (and therefore costly) jobs.

 

A bunch of panels wired together is a decent DC voltage (approx open circuit voltage is # panels x 40V i.e. 400V for 10 panels). And DC is fairly dangerous.

 

The regs say that you need a proper sparky for this kind of work. Theoretically an MCS one if you want to sell back to the grid.

 

Can you not get the original guys back to do you a cheap deal given they didn't install all the panels you expected first time round? They should have known about the power line in advance of course.

 

 

I did actually email them about the power line before work started & I was told to just go ahead with the job & they'd ask NPG about it, then if they had to reduce the string by 1 or 2 panels they'd just take the panels off the bill. However they then said NPG stated they required 2.5 meters clearance from cables so wasn't any point putting up the 1 or 2 panels that were that far away.

 

I won't bore you with the full long story but basically I think the instal company hadn't properly accounted in my quote for the fact 2 of my roof sides are slate & the director basically admitted to me that my job had been a loss for the company financially (proposal said 3 days work but guys were back & forth for 3 weeks). A few other issues such as they wanted to do a time saving bolt through system on the slate roofs, which I flat out refused. They started using builders band as slate hooks so I stopped things & got them to fit the Genius roof system with all the proper flashings & hooks etc. (I spent a LOT of time & money building & slating that roof with my own 2 hands!)

 

This is pure speculation but when there was only the last 10 panels to fit I went on holiday for 2 weeks so all work stopped while I was away. I actually said to my wife on the plane home that I had a feeling they'll probably just say NPG won't let them fit the panels even if they can, in order to cut their losses. Maybe they did, or maybe I'm just cynical.

 

I have spoke with a guy on a Facebook Solar group who claims to be the lead designer for the NPG & he says there should be no clearance needed for concentric double insulated cables (which mine apparently are). I have also booked I an inspector from NPG to come out & settle the matter as they can't do it over the phone but to be honest I'm a bit tired of the whole thing now so I might just cancel the visit & pay for the instal as is (with reduced price obviously) because this has consumed so much of my time over the last month or so as well as being stressful.

Edited November 23, 2023 by glock339

[Dillsue]

2 hours ago, glock339 said:

 

Yes I paid the DNO for approval of a 15.575kW system so hoping this still stands, might there be a time limit etc on this approval?

 

I wasn't aware of a time limit on our G99 approval but that's not to say there isn't something buried in the small print! It took our DNO a good 9 months to change a transformer so there's no rush on their side. If your part system is powered up and commissioned then the installer should have already sent the commissioning docs to your DNO so there'll be no clock ticking for you to add the remaining panels. 

 

If your roof under the power line is the best place for your panels then probably worth persevering with the inspectors visit on the off chance he gives approval for your extra panels

[SteamyTea]

Will these power lines cause shadows on the modules. If so, you may have to fit optimisers as the blocking diodes in the modules may not be up to the job.

[glock339]

I'd like to have thought the installers would have thought of that & I know in their proposal it said there was no shadowing to any of the roofs for whatever thats worth.

 

There's only 2 thin-ish (maybe 20mm to 30mm diameter each???) lines that fly over the roof diagonally then connect to a pole mounted to the side of the house so I don't know if that'd be enough to cause significant shadowing?

[SteamyTea]

2 hours ago, glock339 said:

There's only 2 thin-ish (maybe 20mm to 30mm diameter each???) lines that fly over the roof

As strange as it seems, they could impact performance more than you think.

The total module current is reduced to the current of the lowest performing cell.

This is why bypass diodes are fitted.  The voltage only drops slightly when a single cell is bypassed, but the current is the same.

There are a few YouTube videos about it

[glock339]

On 23/11/2023 at 14:47, Dillsue said:

I wasn't aware of a time limit on our G99 approval but that's not to say there isn't something buried in the small print! It took our DNO a good 9 months to change a transformer so there's no rush on their side. If your part system is powered up and commissioned then the installer should have already sent the commissioning docs to your DNO so there'll be no clock ticking for you to add the remaining panels. 

 

If your roof under the power line is the best place for your panels then probably worth persevering with the inspectors visit on the off chance he gives approval for your extra panels

 

Yeh I decided to just go ahead with the inspection on Monday then at least I know one way or the other if I ever do decide to put panels on that roof. To be honest I was always in 2 minds about installing them on that particular roof side anyway as a couple of years ago I slated it myself & put a lot of extra time in doing patterns in the slates etc to make it look nice, plus they cost an arm & a leg so seems a shame to cover them with panels.

 

However I am a heavy electricity user unfortunately so ideally I would like to take advantage of at least some of the extra capacity I have just sat there in the unused string.

 

 

Edited November 24, 2023 by glock339

[SteamyTea]

23 minutes ago, glock339 said:

I am a heavy electricity user

Try and reduce that by the amount the extra modules would have generated.

[glock339]

21 hours ago, SteamyTea said:

Try and reduce that by the amount the extra modules would have generated.

 

😅 if only it were that easy, next year my usage will be increasing significantly so I definitely need a plan for replacing the missing panels.

[SteamyTea]

59 minutes ago, glock339 said:

if only it were that easy

Why is your usage so high.

I managed to reduce my usage to a third, it is amazing what can be done.

Do you have a decent data logger for your usage, it can easily show what is unnecessary usage.

[JohnMo]

40 minutes ago, SteamyTea said:

Why is your usage so high.

I managed to reduce my usage to a third, it is amazing what can be done.

Do you have a decent data logger for your usage, it can easily show what is unnecessary usage.

But a wife and/kids will try their hardest (unknowingly in most cases) to undue everything you do, or throw teddy out of cot, if you suggest a different way of doing things.

[SteamyTea]

2 minutes ago, JohnMo said:

But a wife and/kids

What are these things you speak of?

 

It is true that living alone makes life easy, but I used to have a brain damaged lodger, got her to understand it and change her behaviour.

Took 2 years.

[glock339]

On 25/11/2023 at 14:30, SteamyTea said:

Why is your usage so high.

I managed to reduce my usage to a third, it is amazing what can be done.

Do you have a decent data logger for your usage, it can easily show what is unnecessary usage.

 

I grow corals, which I'm expanding by around 50% next year plus I'll be 3D printing pretty much 24/7.

Edited November 27, 2023 by glock339

[SteamyTea]

24 minutes ago, glock339 said:

I grow corals, which I'm expanding by around 50% next year plus I'll be 3D printing pretty much 24/7.

The a heat pump to keep the water warm, and some LED lighting should reduce the energy usage.

I grew up on a tropical island, was the first place in the world to introduce a no take zone.  We used to take the black coral all the time.  It grew like a weed.

 

Depending on what you are making, you could 3D print off a pattern, then make a mould/tool, then cast, probably faster, cheaper and better.

 

[glock339]

2 hours ago, SteamyTea said:

The a heat pump to keep the water warm, and some LED lighting should reduce the energy usage.

I grew up on a tropical island, was the first place in the world to introduce a no take zone.  We used to take the black coral all the time.  It grew like a weed.

 

Depending on what you are making, you could 3D print off a pattern, then make a mould/tool, then cast, probably faster, cheaper and better.

 

 

Yeh believe me I use the most efficiently powered aquarium equipment possible but will still be pulling around 4kw per hour during the 8 hour lighting periods & around 1.5kw outside of the lighting period.

 

I actually used to cast resin objects as a full time business in the past, the cost of resins & silicones plus ancillary gear is ridiculous, it takes much more time if you take into account all the different processes involved which most people don't think about, the amount of mess & fumes it creates is absolutely horrific & ideally requires dedicated a workshop space for it. Casting also has a lot of limitations in terms of shapes you can do (undercuts etc) plus resin is not safe for corals, 3D printing in PETG is reef safe & the way to go.

Edited November 27, 2023 by glock339

[glock339]

So I've just had the NPG inspector guy out & got some mixed info from him.

 

He said ideally there should be 1 metre clearance for my type of cables but also said it doesn't really matter & if it was him he'd just put the panels up anyway 😳

 

I should say that he also said that he was going to do a survey recommending my cables are moved & brought into the houses underground so I'm not sure if that had something to do with him saying I could just crack on with putting panels up on that roof. I really did try to push him on what exactly is or isn't allowed in my case but he just seemed to change the goal posts between saying ideally a 1 metre minimum & then saying it didn't really matter if I just put them up as is 🤔

 

Ah well it looks like it's still clear as mud. I may go ahead with them moving the cables though as he said there isn't a charge, which I was a bit surprised at.

[joe90]

39 minutes ago, glock339 said:

I may go ahead with them moving the cables though as he said there isn't a charge,

Well that’s good news!

[Alan Ambrose]

>>> He said ideally there should be 1 metre clearance for my type of cables but also said it doesn't really matter & if it was him he'd just put the panels up anyway 😳

 

Don't you love this? Great that they will be moving your cables foc. Don't hold you breath though - I think it can easily take 2-3 years.

[glock339]

17 hours ago, joe90 said:

Well that’s good news!

 

Yeh I when he was going through the all various works he was going to recommend be carried out in his report I was thinking to myself if this is all chargeable it's going to be silly money & won't make financial sense, so I sheepishly asked if it was & I was blown away when he said it was all buckshee!

[glock339]

17 hours ago, Alan Ambrose said:

>>> He said ideally there should be 1 metre clearance for my type of cables but also said it doesn't really matter & if it was him he'd just put the panels up anyway 😳

 

Don't you love this? Great that they will be moving your cables foc. Don't hold you breath though - I think it can easily take 2-3 years.

 

Honestly I felt like an interviewer trying to get a straight answer out of a politician, it just wasn't happening 😅

 

Yeh after he told me the works were free & saw how pleased I was he then brought me back down to earth by saying "BUT there will be a canny waiting time." I think that's possibly why he was saying in not so manny words that he'd just put the panels up now while the scaffold etc is up then get the cables moved. However unless he actually puts something in writing in his report (I should be getting a copy emailed to me) it seems a bit dicey putting them up because some bloke said it'll probably be ok gov 🤔

[Alan Ambrose]

>>> BUT there will be a canny waiting time

 

I think they often use this strategy (a) to push cash flow and P&L impact down the track and (b) because a lot of people will need it done quicker and therefore have to ante up for it. There's a procedure to formally request it, I'll remind myself and post it up here is as I have to do this myself. Which DNO?

 

>>>  it seems a bit dicey putting them up

 

A technique is to confirm the conversation re minimum distance (not the guy's off-the-cuff remarks of course) in an very polite and professional email and inform them that you are planning to proceed on that basis. Then give it a week or two and press ahead.

 

 

 

 

[glock339]

On 28/11/2023 at 09:42, Alan Ambrose said:

>>> BUT there will be a canny waiting time

 

I think they often use this strategy (a) to push cash flow and P&L impact down the track and (b) because a lot of people will need it done quicker and therefore have to ante up for it. There's a procedure to formally request it, I'll remind myself and post it up here is as I have to do this myself. Which DNO?

 

>>>  it seems a bit dicey putting them up

 

A technique is to confirm the conversation re minimum distance (not the guy's off-the-cuff remarks of course) in an very polite and professional email and inform them that you are planning to proceed on that basis. Then give it a week or two and press ahead.

 

 

 

 

 

That'd be great if you could, my DNO is Northern Power Grid.

 

I like the email idea! 😁