Low cost ground mount idieas?

[bonaire]

General thought. If the $1/Watt ground-mount cost add-on for the system makes it basically "too costly" for payback period, consider not doing it. What about doing an energy review and attempt to cut energy usage instead? Whether it is putting timers on devices like DVRs to cleaning refrigerator coils to using all LED lighting, etc. If you don't do cost-cutting first, no real reason to try to save money with Solar because you have to size a system larger than you really need.

Going with roof mounting instead doesn't remove $1/Watt - it has a lower cost associated but it does have cost. With roof mount, you don't lose the ground-space involved in the ground mount. Some people have to build-up their roofing lumber if the engineering says that the weight of the panels goes beyond the home's original construction specs. That adds cost as well.

I know of a guy living on a farm in Virginia who is off-grid and did ground mount decades ago and recently bought some more panels. He's a unique guy but he does, at times, lay his panels flat on the ground in the summer-time. I wonder if you could do something like a "cold frame" or basic ballasted flat-mount rather than an angled ground mount which are more expensive due to wind-load engineering?

[SolarJoe]

Phillip, you might want to start with a professional have them install, insure, maintain and monitor the system. The company that installed my system was xxxxxxxxxxxxxxxxxx

Mod note - last warning - forget the solar company ad.

[maple flats]

Those thinking of PT lumber for a ground mount, consider this. The PT found at Lowes or Home Depot is not even rated for ground contact. The best PT I've seen is rated 30 years. Solar panels are 50 yrs+, the first panels made in the 40's are still making power. Igf going ground mount use solar mounts unless you plan to re build the mount every 20 yrs or so.

[maple flats]

I used and like the Haticon system, for my original 1480 watts and my current expansion in the works now, moving from off grid at 1480 watts to 6.32 KW grid tied, net metered is using the Haticon.

[Naptown]

Those will need to be included in the bonding.
Use all stainless hardware with isolation washers that are either non metallic or stainless.

[LeRoy]

Thanks so much for the replies.

Do you think there would be any micro-inverter issues when using a pressure treated wood rack?

[inetdog]

Since the spacers would not experience much force, would a small counter-sunk galvanized lag with washer be enough?

I'm not sure I know what you mean by: "you will need to bond each panel individually".

Not sure how the galvanized lag and washer would react with the copper compounds either, but at least the aluminum would be protected.

Re bonding: If you fasten an aluminum panel frame to a metallic structure using the right fittings, you have bonded them together electrically and only one ground wire is needed. If you bolt them to a wood frame, you must run wire bonding jumpers to interconnect the frames so that you can ground them.

[LeRoy]

Since the spacers would not experience much force, would a small counter-sunk galvanized lag with washer be enough?

I'm not sure I know what you mean by: "you will need to bond each panel individually".

[Naptown]

That will work but how are you going to bolt them to the wood and you will need to bond each panel individully.

[LeRoy]

spacers between panels and pressure treated wood

Thanks, Rich. How about nylon or fiberglass spacers between panels and pressure treated wood?

[Naptown]

Pressure treated wood unless properly isolated from the aluminum will cause many problems with the aluminum frames of the modules due to galvanic corrosion.
Copper which is a primary ingredient in pressure treated lumber is about as far away on the galvanic scale from aluminum as one can get. Meaning of this is the aluminum will be sacrificial to the copper. Dissimilar metal when in the presence of moisture which will happen outdoors will create a battery. The aluminum in this case is the anode which will corrode.

[LeRoy]

Pressure treated lumber PV racks

I am considering using properly graded 4 x 4 or 4 x 6 pressure treated lumber for ground based racks for a 4.5 Kw system. The array will need to be two panels high (roughly 10' maximum height above ground). Has anyone had any experience with this idea?

[Philip]

I may have to break down and call in one of my mechanical engineer friends on Superstrut. We used it all the time so I'm sure they are familiar with it. ULA looks like it may do the trick though.

ULA does look much better, more like 70 cents/W list. If it is discounted enough, that could do the trick.

Thanks all, this is the help I was looking for. I'll still also follow up with Haticon when the time comes. There stuff looks very good as well.

[Naptown]

Again, that's over a buck a watt! Yikes that's expensive!

One way the quote from their tool is flawed though, is that it only seems to allow landscape layout, which requires twice the rails and rail-roof attachments it needs in portrait.

I'll do a layout and submit it to them for feedback. I'll do the same for Haticon, their system looks much cleaner for ground mount.

If you are looking at the pricing on Unirac's website that is list price. generally you can find it for about 35-40% off list.

[Naptown]

Again, that's over a buck a watt! Yikes that's expensive!

One way the quote from their tool is flawed though, is that it only seems to allow landscape layout, which requires twice the rails and rail-roof attachments it needs in portrait.

I'll do a layout and submit it to them for feedback. I'll do the same for Haticon, their system looks much cleaner for ground mount.

That is done to keep the overall height and therefore moment down. yes the rails run vertically but many modules are not designed to be mounted from the ends they need to be balanced over the rails or the loading from wind and snow is reduced by half or more. However the rail length per module is about half of what it would be running the other way ( basic module dimensions of 39 x65 with rails running across the module on the short dimension = 78" per module running the other way is 135"