Add Panels on Steel Tech Shed

ah, wouldnt worry.

K2 micro rails are the easiest install ever. The self tapping screws have a built in rubber washer that ensures water proofing. This is also the cheapest possible way to mount panels. So not only DIY friendly, but also giving the shortest possible pay back time.

A well timed thread. I was planning similar but didn't get as far as looking at rails, except I spotted this on watuneed.

I presume that these shed based systems will be on microinverters?

I like that - respect.

Good stuff. Make sure that there's no water ingress onto that wood. Last thing you want is over a few years for the wood to rot and then it becomes brittle and a good wind takes the lot away. Bolts are better (if that's an option)

Sounds like you got it covered. I was also paranoid with my own DIY installation for water egress. Like you my shed roof is very accessible and I don't mind popping up to check it, but at the same time want to get decades out of it.

I am as happens wondering if I should open more ventilation along with adding the panels. it seems the only current ventilation is at the eaves, some at the ridge would be better as its an oven in the summer. but probably best putting a vent in each gable end.

I hate to bring it up, but how are people dealing with earthing, or more precisely equipotential bonding, on sheds with micro-inverters? I'm not an electrician, but I'd be of the opinion that the shed needs to be bonded to the CPC/earth on the AC feed cable, but that there may be instances where the shed requires a local earth.

The risks of getting this wrong and having a cable fault and short to the shed or to the mounting hardware far outweigh the gains, hence I'm asking.

I ran 6 sq swa cable out to the microinverters, used that to earth the frame of the shed. Between the swa and the 6 sq earth it should be more than adequate. Having a low enough earth loop impedance is the critical factor here so your overcurrent device will trip in the required time in the event of a fault. Each panel is bonded, as is the metal sheeting under the timber frame. The mounting rails should also be connected.

Well, this is part of my question, specifically for microinverters.

I think that the metal of the shed is considered to be an extraneous-conductive-part and needs to be earthed (ie, parts of it connected with 10mm2 earthing cable), but that the metal support frame for the solar panels, where the microinverters are installed to and the AC cable clipped to, would need to be bonded back to the SWA and CPC.

I had a look at the specific microinverters I am using (enphase m215). They don't have a dedicated ground attachment, and their product sheet says they have integrated ground.. so do not need separate grounding. They've ground fault protection also. They do say that by code, the panels and rails should still be grounded, I think the same applies whether microinverters are used or not. So, I'll stick with the earth in the ac cable for the inverters , and add a separate ground for the shed frame.

Following this one with interest as part of my own plan for my panels is splitting my panels across 2 south facing roofs. 1 on the house and the other the south aspect of a Steeltech shed. The consumer unit in the shed is earthed via 10sq back to the main house. I'd never considered a 2nd earth rod for the shed might be needed 🤔

I'm of the same opinion 10-10-20 (love the name btw). Earth is earth, so routing back via your consumer's (house AC earth) should be the same. That said, if there was something that I'm missing for example some ELCB vulnerability where you could get "trips" from some leakage from the DC side, I'd like to know that. The documentation/information I've seen on the topic seems misleading/confusing. So appreciate the question being asked here.

However, I think the main thing is to make sure that the rails & panels are earthed in some fashion. House's AC earth or it's own DC earth for the shed. That's the main thing

I am a little different from you though. I don't have rails. My panels are screwed onto 2x4's for me, which in turn are affixed to wooden mountings, and they are connected to wooden rafters inside the dual layer perspex roof, on a cement shed. So I wouldn't have the same path to earth as you would. That said, I wouldn't want a 50v charge on the panels either, should I ever go up on the roof to check something and get zapped :-)

Ya the same thought crossed my mind, and from the reading I did on this, I came to the the conclusion that the panels are no more likely to be hit by lightning than any other part of the house. A type 1 surge protector would help but a direct strike would probably destroy everything. It should protect against an indirect strike. I would like to speak with a lightning protection expert on this, as it wouldn't cost much to add a lightning rod and a bit of tape.

Everything I'm reading including 10 10 20s posts here and in electrical forum is suggesting that separate earth for shed just isn't done in Ireland. Ive 3 core swa out to the shed, the inverters are actually an earlier revision, they do need grounding. They suggest ground via separate swa or direct to racking and I have the washers so the latter is what I will do, then bond panels and racking to ground via existing swa/cpc .

Mine are at 15 degrees on a Steeltech shed. Haven't noticed any dirt other than a few leaves which have come off quickly enough.

I notice though that the shed has slightly less generation in Nov and Dec than the roof panels at 35 degrees, but it has been very mixed in terms of generation during Winter anyway.

Microinverter into a socket as the shed is already wired for mains. It's only a 700w microinverter in my case, not a mini-power-plant like graememk. 😁

I went under garden into the garage and then along the eaves to the consumer unit

could it go into an outdoor light?