Self installing solar modules and inverter

[Radian]

Given that we run an electronics workshop and music studio from home and therefore have a base load of well over 1kW during the day, it's long been an ambition to get a PV array on the workshop roof. Unfortunately just as I was pulling the trigger world events intervened sending half the country (or so it seems) flocking to the doors of PV installers. I'm having trouble just getting them to pick up a phone. When I do get a answered, I'm not hearing things I'm happy to settle with. In the topic I started about AC cable length  it was suggested that I find myself a roofer and get them to fit modules (a task I'm physically unable to do myself).

 

But what are the regulatory hurdles that need to be overcome to do this anyway? Anyone should be able to buy the components - modules, inverter, racking, isolators and cable and do a mechanical install. A Part P electrician can install a new circuit and connect up the system. If the system is under 3.68kW it does not need a generation licence.

 

The G98 application form is available on the energy network association website which also has connection guidance for G98 The form however asks for Installer
Accreditation / Qualification which sounds like the first hurdle. This presumably means MCS accreditation. The MCS website hosts a Guide to the Installation of Photovoltaic Systems which is not very informative in this regard.

 

Another aspect seems to be the structural implications and possibly the involvement of building control. There are companies who will do a Desk Top Structural Roof Appraisal for around £100 if you fill in a survey form. This should keep BC happy and go some way to legitimising the installation but if the objective is simply to use all the generation you can and not expect payment for what you export, but is this enough?

 

 

[Nickfromwales]

If you can convince yourself that you will self-consume at least the lions share of what you generate, then do as @ProDave @canalsiderenovation and others have done and DIY for as cheap as you possibly can. Any decent electrician should be able to do this from start to finish. Installing the trays / mountings etc couldn't be easier, but a roofer cannot run DC cabling and make off MC4's so I would not pursue that advice tbh.

Edited March 9, 2022 by Nickfromwales

[ProDave]

9 hours ago, Radian said:

The G98 application form is available on the energy network association website which also has connection guidance for G98 The form however asks for Installer
Accreditation / Qualification which sounds like the first hurdle. This presumably means MCS accreditation. The MCS website hosts a Guide to the Installation of Photovoltaic Systems which is not very informative in this regard.

Mine was done under the old system G58 I think?

 

All I had to provide was details of all the equipment and make and model of the inverter. a drawing of the installation showing positions of the isolators and an electrical drawing and the completed forms.  They didn't ask for any other certificates or proof of qualifications, but I am sure the Part P certificate and EIC from the electrician would satisfy that.

[SteamyTea]

Just make up a company, or copy the details of one that is MCS registered onto the paperwork.

Only checked when it goes wrong, and by then, most companies have vanished.

 

I am sure if the DNO is happy, the problem is solved.  The structural element is really for your house insurance.

[Radian]

10 hours ago, Nickfromwales said:

Any decent electrician should be able to do this from start to finish. Installing the trays / mountings etc couldn't be easier, but a roofer cannot run DC cabling and make off MC4's so I would not pursue that advice tbh.

 

😄 I can't help thinking the exact opposite; that clicking in a daisy chain of MC4's and tie-wrapping some cables down towards the eaves would be well within the capabilities of a roofer - while locating rafters, lifting and cutting slates and replacing with a flashing kit might be a bit of a stretch for an electrician. A single string with polarised connectors surely is a total no-brainer? More importantly, what exactly can go wrong if the cables are secured and kept off the slates? If it wasn't for the steep (50 deg.) roof and a few other impediments, I'd be up there like a rat up a drainpipe.

 

1 hour ago, ProDave said:

All I had to provide was details of all the equipment and make and model of the inverter. a drawing of the installation showing positions of the isolators and an electrical drawing and the completed forms.  They didn't ask for any other certificates or proof of qualifications, but I am sure the Part P certificate and EIC from the electrician would satisfy that.

 

If you don't mind me asking, what were the forms you completed and where did you send them?

 

1 hour ago, SteamyTea said:

Just make up a company, or copy the details of one that is MCS registered onto the paperwork.

Only checked when it goes wrong, and by then, most companies have vanished.

 

I am sure if the DNO is happy, the problem is solved.  The structural element is really for your house insurance.

 

Ah, the fradulent approach 😁 While always a temptation the aim of this topic is to establish a 100% legal approach to DIY solar installation. To me, the regulatory issues around installing solar kit seem like a little bit of overkill. I view it like any other electronic equipment I own, such as Welders, compressors, Laser cutters and so on. These all make a connection to the grid which, depending on how you view it, is protected by the DNO's 100A fuse. Now admittedly, when feeding current into the grid then yes - it shouldn't be allowed for any old rubbish to push back in. But this is the point of type-approval. If the equipment injecting that current is type-approved, then however it is fed (i.e. the PV array) is inconsequential.

 

However, I appreciate  that there are other hazards presented by power generating devices. Much like having a bunch of Lions lounging on your roof, it can hurt if provoked. Aside form the hazards presented to the property owner, visiting emergency services must be able to operate safely and hence isolate the panels in an emergency. So certain standards must be adhered to (as set out by the ENA) and some level of enforcement must be expected. This doesn't need to be prohibitive and can well be covered by part P which is all about electrical safety.

 

So my question now becomes 'do all solar PV installations need to be performed by MCS accredited installers?' Googling that exact phrase is eerily like a response from the ministry of (mis)information... heavy promotion by bodies with vested interests in the 'scheme'. I can't seem to get a straight answer to this reasonable sounding question.

[Dillsue]

The G98 is a notification, not an application. You tell them after the event what youve done, if atall. Our DNO has no record of our FIT system installed by an MCS installer in 2015!

 

Use a part P spark to test and certify the AC connection although I think the DNO is mainly interested that the inverter is G98 compliant with 16amp limitation.

 

If your garage roof is rickety then by all means get a structural engineer and building control involved, but your roofer/joiner will be able to give you a practical veiw on the structural state of the roof. With SE/BC youll bury yourself in red tape and cost.

 

In the previous thread you said you were more than capable of doing all the work except the roof work, which is why I suggested to use a roofer to fit the mounts and drop the panels onto the mounting rails. Panels plug together with MC4 connectors and I sure thats within the capabilities of a roofer or yourself off single storey scaffold.

 

PV install is straight forward and easily DIYable with the only proffessional help being a part time spark.

 

Go for it before everyones at it and prices start to climb. 

[Dillsue]

MCS is only required if you want to get paid for export. With 2.4kwp and batteries youll likely only ever export significantly when youre on holiday but certainly not enough to warrant the premium an MCS installer charges

[jamieled]

12 minutes ago, Radian said:

do all solar PV installations need to be performed by MCS accredited installer

I installed my own ground mounted PV system under G98 (16A limit). I used an electrician to wire up the panel strings to the inverter, the isolators and the AC cabling into the house isolator/CU/meter. They weren't MCS registered and I don't think they'd done a lot of PV work but didn't seem to think it overly complicated.

 

The G98 form I had to fill in for the DNO (SSEN) asked for installer details. I just put down my name/address and added a comment that the electrical work was undertaken by a a qualified electrician (didn't specify who). They didn't query anything.

[Nickfromwales]

24 minutes ago, Radian said:

😄 I can't help thinking the exact opposite; that clicking in a daisy chain of MC4's and tie-wrapping some cables

And the ends of the strings which need the MC4's crimping? PROPERLY? And the risk of death when they try to do all this during the daytime with zero prior experience.

BAD idea.....

[CotswoldDoItUpper]

5 minutes ago, Nickfromwales said:

And the ends of the strings which need the MC4's crimping? PROPERLY? And the risk of death when they try to do all this during the daytime with zero prior experience.

BAD idea.....

Not suggesting this, but would a suitably placed tarpaulin covering the panels help to mitigate the risk of them being ‘live’?

[LA3222]

9 minutes ago, Nickfromwales said:

And the ends of the strings which need the MC4's crimping? PROPERLY? And the risk of death when they try to do all this during the daytime with zero prior experience.

BAD idea.....

Is it that hazardous? As I see it there are two wires going from inverter to panels, but when they need crimping just don't connect them up to owt. Cut to size, crimp whilst unconnected and then its a case of connecting all the MC4s together?

[Marvin]

16 minutes ago, CotswoldDoItUpper said:

Not suggesting this, but would a suitably placed tarpaulin covering the panels help to mitigate the risk of them being ‘live’?

Leave unconnected until night time. Hence my neighbours thinking Santa was early last year.

[SteamyTea]

A decade ago I know, but we did not have any qualified solar installers fitting our kit.

We just used 'lads that had done some roofing'. Though we did employ an electrician to finish the wiring. 

Luckily the company was run by a crook and did not last very long. 

[Radian]

23 minutes ago, Nickfromwales said:

And the ends of the strings which need the MC4's crimping? PROPERLY? And the risk of death when they try to do all this during the daytime with zero prior experience.

BAD idea.....

 

Of course it's would be a bad idea to crimp a live cable carrying over 48V DC. That's obviously why you don't do it. Nor do you have to given that panels are terminated in gendered MC4 connectors. Any extension cables can be prepared disconnected and finally connected in the safe manner that they are designed to be. This is all very obvious so I guess you're just emphasising the potential dangers if insufficient supervision or understanding is employed. IMO Your observation in no way means DIY installation should not be undertaken.

[Radian]

Incidentally @Nickfromwales, after reading this other topic, I'd be interested in knowing what kind of margins you would expect to see? 

 

The  "mcs certified" website has a guide book that says:

Quote

In determining the appropriate pressure coefficient to use in calculations, the location of the PV array on the roof needs to be determined as some, or all, of the array may be in the “Edge Zone” as defined in BS EN 1991-1. 

 

A reading of BS EN 1991-1 is not a trivial undertaking, I can't see any installer working though this so I'm guessing there's a 'rule of thumb' applied in the field.

[Radian]

To continue the issue surrounding safety of installation, another approach is to use microinverters attached to the racking beneath the modules. The direct plug & play nature of these eliminates high DC voltages and anti-islanding makes the AC output harmless until such time as finally connected to the consumer unit via the AC isolator. While offering other advantages, such as minimising losses through partial shading, the worry for me would be maintenance should an inverter need replacing.

[Marvin]

1 hour ago, Radian said:

Incidentally @Nickfromwales, after reading this other topic, I'd be interested in knowing what kind of margins you would expect to see? 

 

The  "mcs certified" website has a guide book that says:

 

A reading of BS EN 1991-1 is not a trivial undertaking, I can't see any installer working though this so I'm guessing there's a 'rule of thumb' applied in the field.

My rule was top height below a horizontal line from the ridge (planning regulations I think) and 300mm from the roof sides.

Loads: well, we just had 120 mile an hour winds a couple of weeks ago and there all still there, and now I wait for the one foot of snow test....

[Dillsue]

If this install is on a garage roof and theres access to the underside of the roof mount micro inverters or optimisers in the garage roof where they are accessible anytime.  Get the roofer to notch the tiles and feed the cables through a slit in the felt next to a rafter

[Radian]

1 hour ago, Marvin said:

My rule was top height below a horizontal line from the ridge (planning regulations I think) and 300mm from the roof sides.

Loads: well, we just had 120 mile an hour winds a couple of weeks ago and there all still there, and now I wait for the one foot of snow test....

 

Looks like it goes up to the bottom edge of the ridge tiles? if that's OK then I can fit three 1690mm tall panels vertically and leave 230mm at the bottom so rain doesn't overshoot the guttering. Loads of room to the sides. That's why I was interested, thanks.

 

1 hour ago, Dillsue said:

If this install is on a garage roof and theres access to the underside of the roof mount micro inverters or optimisers in the garage roof where they are accessible anytime.  Get the roofer to notch the tiles and feed the cables through a slit in the felt next to a rafter

 

That would have been an excellent idea but the garage has a room-in-roof conversion so the ceiling is in the way.

[Radian]

Looks like we're going to chicken-out and get it installed... ~£4k for a 3kWp system, no battery. Looking at PVGIS and Solcast I predict we can self-consume the lot with a few automated 'smarts'.

 

I have however been accumulating a small collection of panels and inverters over the last few years so there's always scope for a future 'garden project' to augment our overall generation capacity. I would add that this would be directed towards off-grid applications. Out of all the documents I scraped to read-up on PV installations I found guidlines for solar pv system installation for solar providers to be most practically useful - aside the fact that it originates from Sri Lanka 😄

[markharro]

I too am thinking about a self instal in due course. I have caught a whiff of chat of rising PV panel prices coming later this year......is there an argument to buy now even though I wouldn't instal for at least a year? We will have lots of roof space so any tips of sourcing cheap/second hand lower wattage panels? thanks.

[Dillsue]

If you want cheap/secondhand panels then ebay. If youre not bothered about matching panels then just buy as they come up at the right price/near by. Bare in mind that if youve got electrically mismatched panels, the lowest output panel will bring the output of the whole array down, unless wired in what could be complicated wiring if youve got a few variants of panel.

 

Micro inverters or optimisers get round panel mismatch so a good solution if your collecting panels as you go.

[Radian]

There's supposed to be a government announcement in the coming weeks about an update to our energy independence strategy. Mention was made in a Times article (behind a paywall) about help with the cost of installing PV. That in itself will push up prices 🙄

[Dillsue]

13 hours ago, Radian said:

 Mention was made in a Times article (behind a paywall) about help with the cost of installing PV. That in itself will push up prices 🙄

I dont know if it will???? A few months back I started a WhatsApp group of about 15-20 contacts who I knew could fund a PV install with a view to bulk buying as a group and hopefully enjoy some sizeable discounts. 1 person had already installed solar and no one else was interested!

 

 

[CotswoldDoItUpper]

41 minutes ago, Dillsue said:

I dont know if it will???? A few months back I started a WhatsApp group of about 15-20 contacts who I knew could fund a PV install with a view to bulk buying as a group and hopefully enjoy some sizeable discounts. 1 person had already installed solar and no one else was interested!

 

 

I’d be interested to join a BH version for those who are looking at it now…?