Pv panels location, ground level behind house.

Whatwicklow

Hi, I have a complex roof on my south facing house, no matter the location I am compromised with a shadow.

I do own a field behind my house that has no shade, is there any reason why panels can't go at ground level or what are the thoughts on that for a solution?

I am looking to DIY a c4kw system and putting them ground level makes it a lot easier.

Thoughts?

the_amazing_raisin

In general ground mounted arrays are easier to setup than roof mounted. I haven't seen any mounting systems available but I'm sure if you looked online you could find some

Depending on what you're using the field for you'd obviously need to give room to work around them

Why not go bigger and sell some electricity back to the grid? I think they're giving 13.5c/kWh for systems above 6kWp

graememk

https://www.boards.ie/discussion/comment/118764969#Comment_118764969

the base of 13.5c /kwh is for Non Domestic connections. even farmyards that have a MIC of up to 20KVA are domestic connections.

here are some ground mount options https://solartricity.ie/ground-mount-options/

the_amazing_raisin

Missed the non domestic bit, thanks for spotting that

Whatwicklow

All good info, thanks. There are one stop shop kits available on that link. I'll give them a call and see what is recommended and what the €€€ are.

slave1

If you are handy you can drop 3/4 supporting posts into the ground and work out a tilting array without much bother, there are plenty of YT vids on it. Tilting will greatly increase your generation and when you have that option would be a crime not to incorporate in.

unkel

A roof is a free mounting system already there. For a large array, throw in a few hundred quid in parts (plus the PV panels) and you're done. The same system as a ground mount would cost a few thousand in materials alone (plus the PV panels).

Not saying you shouldn't do it, if your roof isn't feasible or not enough and you have the land, by all means go for it. Make sure you do your sums though, it will take a lot longer to pay for itself particularly if you don't fully DIY it. Possibly twice as long.

Big Lar

Few old telephone poles does the trick

bullit_dodger

You posted a similar picture before Lar and have to say, still impressed with that.

One thing I noticed though is that you might have some shading (at least in the picture there) on a few panels. This will probably go away when the months progress in the year, but have you considered or found the need for optimizers?

Whatwicklow

Went down the worm hole on yt last night looking at all sorts of complicated tracking and tilting frames cobbled together from scaffolding, bamboo, 4*2 etc, loads of solutions

That one on telco poles looks super sturdy.

Not too hung up on the structure, it's looks to be something I'll be capable of. it's the electrical kit that now seems complex,

SouthWesterly

https://www.boards.ie/discussion/comment/118779742#Comment_118779742

@irishchris did a DIY job and has photos up somewhere on the forum.

SouthWesterly

https://www.boards.ie/discussion/comment/118777251#Comment_118777251

BL what did you bolt the panels on with?

bullit_dodger

https://www.boards.ie/discussion/comment/118779742#Comment_118779742

My recommendation is to forget the "tracking" and just go for a 1-axis adjustable "tilt".

Why? Because it's simply not worth the complexity for the gains that 2x axis gives you.

Solar Trackers: What You Need to Know | EnergySage

Specifically.....

The biggest benefit of a solar tracking system is that it offers a boost in electricity production. Generally, a solar panel system with a single-axis solar tracker installed sees a performance gain of 25 to 35 percent. A dual-axis tracker bumps performance up by another five to 10 percent.

It's a return on investment thing. The complexity is higher with the gimbals, the equipment is more costly. It's easy enough to do something with some angle iron and make an adjustable 1x mount with (say) 3 settings. Winter, Spring/Autumn and Summer. This will give you a nice boost in generation for relatively easy investment and maintenance. You manually change the settings every 3 months and your done. If you really want the an extra 10%, just add on an extra panel €150 to your array and your done! (11 panels instead of 10 etc)

SouthWesterly

https://www.boards.ie/discussion/comment/118780576#Comment_118780576

What kind of angles would you need for seasons?

irishchris

https://www.boards.ie/discussion/comment/118780016#Comment_118780016

Just completed final array this week on new ground mount. A further 2.6kwp and should be the final one bringing my arrays in total up to 10kwp.

SouthWesterly

https://www.boards.ie/discussion/comment/118781073#Comment_118781073

Have you photos Chris?.

I'm buying a second hand inverter this week with a view to starting my additional panels this year. Plan to start with an additional 2kw of panels but will leave room for more.

irishchris

https://www.boards.ie/discussion/comment/118781089#Comment_118781089

Unfortunately didn't take any photos when doing it other than this one when finished but it is similar design just done a bit tidier and more efficiently as the original install which I put photos up in recent thread.

The new array is the furthest one in this photo and is 380w x 7 panels. This is one string and the other string on this inverter is the existing 12 X 360w panels.

Also then have the SAAS 2.88 on the roof.

The ground mounted array made a tidy 27kwh today considering it was a shower filled day. Now the fun part of kerbing them off and stoning the area begins.

bullit_dodger

https://www.boards.ie/discussion/comment/118781067#Comment_118781067

Couple of calculators online, but a quick search threw this up.

Solar Angle Calculator | Solar Panel Angle Calculator (solarelectricityhandbook.com)

So that would be Winter 14 deg, Spring/Autumn 37 deg and summer 60 deg. (for Dublin), you could get more granular of course, with 6 settings, but it's marginal (only 1-2% for the extra settings) . Three should see you right.

Only thing to be aware of, and I should say I don't have one myself, is that you need to be careful that the panels don't behave like a "sail" when they are veritically mounted in the wind.

SouthWesterly

https://www.boards.ie/discussion/comment/118781160#Comment_118781160

Thanks for the link.

@irishchris nice set up. I like the idea of slightly different angles on the arrays. I'm going to have to build it into my design.

Where did you get the kit?

irishchris

https://www.boards.ie/discussion/comment/118781309#Comment_118781309

Yep the 12 array is with facing and the new array is south west facing with lower 35° angle.

The 4x4 posts & 4x2 timber from topline hardware, 42mmx42mm slotted unistrut from any electrical supply shop and panels from solartricity

SouthWesterly

https://www.boards.ie/discussion/comment/118781343#Comment_118781343

Seems to be a, shadow at the end of the first array.

irishchris

https://www.boards.ie/discussion/comment/118781372#Comment_118781372

It's a trick of the light. It's actually a reflection of the trees behind them as sun is actually in front of the panels albeit it was in the middle of showers. The first week I put them in I spotted that from distance and was trying to figure out what was shading them until I walked down to them and realised there was no shade 😁

spose

Did you have to set up a way to limit export?

irishchris

https://www.boards.ie/discussion/comment/118781617#Comment_118781617

Yes set export limitation to 6kw in the inverter settings

spose

Is that a solis? Can I ask where you got the CT for it?

irishchris

https://www.boards.ie/discussion/comment/118781903#Comment_118781903

The CT for main house grid comes with the Solis hybrid inverter as standard

Big Lar

https://www.boards.ie/discussion/comment/118780018#Comment_118780018

I bought the K2 brackets for roof mounting, they had an 8mm hole for the bolts, drilled that out and used 120mm M10 Stainless Steel coach screws, bit of overkill perhaps but its done now.