Yes ELVs <50Vdc.  IMHO its sheer madness to be involved with MV dc Panel strings - way too dangerous  IMHO in a domestic environment, and we dont have the skilled tradesmen to recognise this type of micro grid nor is there a recognised route to upgrade to this unfamiliar but hazardous system.  Way too many unschooled wannabees playing with fireworks.  It is utter negligence by our Political leaders to allow this to continue.  They only woke up to the hazards of amateur plumbers who didnt understand flammable atmospheres till a few houses were blown up flattened.  Then British gas had to step in a institute proper training courses with local tech colleges.  Where do our Electricians get proper upgrades?  A one man jobber cant afford an apprentice (with all the paperwork and oversight involved). He will only have a family member or friend involved.

Well Alan that sums up our typical bureaucratic incompetence we've come to expect. Armchair diktats from faceless mandarins.

IMHO if you can at all then instal ground level panels.  There are numerous horror stories of roof panels - gggle and yt for info.  Tip to consider as its new build, install a cat walk tray on your roof ridge and make it accessible from a gable end by ladder. Its and unobtrusive convenience for maintenance which you will need.

Wire each panel with its own cable thru ridge into loft space and route to a marshalling cabinet and maybe use panel optomisers. You avoid the dubious MC4 connectors (use barrel but splice ferrules and heat shrink apply si grease around metal then a 50mm length of 4:1 adhesive sleeves - these make a water resistant cover

Beware of fake Solar cable (4mm2 solar as 6mm2 solar)

Are you sure your location and insolation (sunshine hours) can justify the full expense of a solar system - capex vs payback time (10yrs +).  Dont believe Solar cowboy calcs. Octopus are just a shed load of accountants check very carefully TnC.  How much energy do you expect to export? Is it really worth it, store your excess as hot water or underfloor heating.  This Solar thing in Scotland has to be one of those political panjandrums  BEWARE

Martyn said:

However, SEG and export are not worth the aggravation for the payback these days

I tried doing some rough example calculations.  Say you average 2kW export for 6 hours a day.  Sign up with a supplier who offers £0.15/kWh.  That's about £657 per year.

The panels could pay for themselves in 10 years.

(use barrel but splice ferrules and heat shrink apply si grease around metal then a 50mm length of 4:1 adhesive sleeves - these make a water resistant cover

Are you sure such an arrangement would meet BS 7671 requirements for joints (526.5)?

   - Andy.

Simon Barker said:

The panels could pay for themselves in 10 years.

Have you amortised the total cost of installation inc wiring switchgear inverter (fails in 5 years maybe) panels need replacing etc?  Batteries?

AJJewsbury said:

Are you sure such an arrangement would meet BS 7671 requirements for joints (526.5)?

I cant justify purchase of IEE regs plus add plus the user manual, not a practising designer anymore

can you quote the relevant excerpt 526.5 that outlaws crimped joints?

OBTW what I meant was "paraphrase" the relevant passage (mustnt violate copyright), but explaining/discussing an extract is ok

can you quote the relevant excerpt 526.5 that outlaws crimped joints?

It wasn't the crimp I was alluding to, but the method of enclosure...

526.5 Every termination and joint of a live conductor or a PEN conductor shall be made within one of the following or a combination thereof:

(i) A suitable accessory complying with the appropriate product standard

(ii)An equipment enclosure complying with the appropriate product standard

(iii) An enclosure partially formed or completed with building material which is non-combustible when tested to BS 476-4.

which a bit of heatshrink doesn't obviously meet, if used on its own to extend tails to reach your marshalling boxes.

   - Andy.

(mustnt violate copyright)

I think we're OK with small extracts for the purpose of academic discussions

  - Andy.

Surely this doesnt apply to ELV <50V systems?  You refer to heatshrink protection.  Some of the quality products seem to be very well suited to outdoors UV resistant, adhesive forms a sealed clamp on a round sheath.  I would put additional coat of Si grease on the metal parts of the barrel and around wire strands after crimping and use a 50mm length sleeve - seems belt and braces to me.  But then electrolytic corrosion can only occur with a positive and negative splice being close together in the event of a moisture path - seems remote risk.  You dont see auto wiring harnesses suffer unless in extreme circumstances.

Rob Tes said:

Have you amortised the total cost of installation inc wiring switchgear inverter (fails in 5 years maybe) panels need replacing etc?  Batteries?

Panels should have a warranty of 20 - 25 years.  Inverters these days tend to come with a 10 warranty, or more.  I assumed no battery.

Rob Tes said:

Have you amortised the total cost of installation inc wiring switchgear inverter (fails in 5 years maybe) panels need replacing etc?  Batteries?

Panels should have a warranty of 20 - 25 years.  Inverters these days tend to come with a 10 warranty, or more.  I assumed no battery.