Cheapest possible galvanised steel ground mount.

[Luk88]

Here are few pictures of the cheapest galvanised steel/aluminum ground mount I found to buy (for 24 2.3x1.14m panels mounted vertically in two rows)

What do you think? Especially about the "unusual" way to make the posts longer.

It consists of:
- 25 2.3m (90in or 7.5ft) fencing posts (they are 2mm/14 gauge galvanised steel).
- 24 aluminium mounting profiles.
- A2 stainless bolts/nuts
- aluminium holders, profile joining brackets

I had to cut the posts to length and drill the bolt holes.

Currently this is just the supports sitting in 80cm (31in) deep holes that will be filled with concrete. Aluminium channels will be mounted horizontally on this.

I plan to use long steel channels clamped on top to straighten and align it all. Then to pour concrete and once it sets attach aluminum channels. I'm also going to use a zink spray paint to improve the corrosion resistance where it was cut/drilled.


(behind is my old array, there will be a little shading, but I'll likely be moving it at some point).


I paid a very low price for it(a third of what a normal ground mount costs) and the seller honestly says he never did any wind load calculations, but "they've been selling it for years" with no problems. In my area things are usually designed for a max wind load of 100km/h (60mph).

I decided to give it a try as I can always make it stronger later if necessary.

 

[Luk88]

Also a question, how straight do these ground mounts have to be? I'm taking about normal panels with aluminium frames.

I've built a ground mount unit for frameless panels mounted with rubber grips. These were very forgiving.

I spent ages getting these aligned perfectly (before concrete is poured into the holes) and by the time I got to the end the middle sagged a bit as shown.


In the last picture the top rail deformation is somewhat exaggerated due to the angle.

I made sure the distance between the supports is exactly right. They are square.

And now I'm in need of a bit of advice. What is the usual tolerance these things are made to? This one is 14m long.

(I expect I might have to put some washers to ensure proper mounting here and there)

Edit: I have a couple 6m long steel channels. I plan to clamp them on the mount where I see deformation before I pour concrete. Perhaps it'll help.

 

[SunDave]

Hi Luk88,
Instead of washers under panels, consider shimming up the rails that the panels mount to before you begin mounting. You can make it look really nice yet if you spend a bit of time on it now.

You will have a nice array there.

 

[Luk88]

Thanks @SunDave

Finally concrete has set properly. I've installed white geofabric (it'll not stay white for long, but I might get some white stone for on top of it. This is becpanels are bifacial and the front gets very near the ground so I'd rather not gave to mow in front of it every 2 days).

And first two panels were installed just to see how difficult /easy is to move these monster sized panels. IMO it is completely impossible on your own. My wife has been helping, without her I wouldn't be able to do it.