We have also switched to using the ground screws. The Sunmodo racking is very similar to Ironridge, but significantly less expensive.
Chris, what do you use for a pilot hole? We often run into rock here, and have experimented with a few ways to get through it. Ideally we would just drill a 3" hole, but I don't think 3" augers exist. I had picked up a rock bit second hand and had a 5' steel shaft fabricated to attach it to. This worked out alright until we melted it all out on a site where there was more rock than soil. Right now, I have an 1-5/8" 5' rock bit for a 2" SDS max drill. which helps in some situations. If the ground screw wont go in, then we can pull it out and try to break up the rock with this bit. But if there is too much rock, then we need to last minute change over to digging it out and using concrete and sonotubes, which gets really expensive. Cheers, Dave On Thu, Oct 22, 2026 at 12:54 PM Christopher Warfel < [email protected]> wrote: > We have used them for 15 years (Krinner) For small jobs we used a adapter > for screwing in by hand. An auger made the pilot hole. For larger projects, > used an adapter to a Bobcat or similar. A pilot hole helped. For that > technique, you really have to work to keep the drive vertical. It tends to > angle due to the way the machine's attachment are works. Chris > On 10/22/2026 12:36 PM, Jason Lord wrote: > > Hi Wrenches, > > For a long time, we have installed ground-mounted arrays using 1' diameter > holes, 4' deep, filled with concrete and 2" schedule 40 pipe. Increasingly, > I am seeing ground screws as an alternative that could save time, disturb > less ground, and reduce costs. > > Has anyone made the switch to ground screws? I feel that similar equipment > would be needed for driving the screws as is used to auger the concrete > based holes. How has this worked for you in reality? > > Best regards, > Jason Lord > > -- > [image: Mendocino Solar Service] > Jason Lord > Owner > Mendocino Solar Service > (707) 937-1701 | [email protected] > mendocinosolar.com <https://www.mendocinosolar.com/> > Connecting Mendocino County to Solar Since 1994 > CA License #536983 · B, C-10 > > _______________________________________________ > List sponsored by Redwood Alliance > > Pay optional member dues here: http://re-wrenches.org > > List Address: [email protected] > > Change listserver email address & > settings:https://lists.re-wrenches.org/mailman/options/re-wrenches_lists.re-wrenches.org/ > > There are two list archives for searching. When one doesn't work, try the > other:https://www.mail-archive.com/[email protected]/https://lists.re-wrenches.org/pipermail/re-wrenches_lists.re-wrenches.org/ > > List rules & etiquette:http://www.re-wrenches.org/etiquette.htm > > Check out or update participant bios:http://www.members.re-wrenches.org > > -- > Christopher Warfel, PE > ENTECH Engineering, Inc. > PO Box 871, Block Island, RI 02807(401) 447-5773 > > _______________________________________________ > List sponsored by Redwood Alliance > > Pay optional member dues here: http://re-wrenches.org > > List Address: [email protected] > > Change listserver email address & settings: > > https://lists.re-wrenches.org/mailman/options/re-wrenches_lists.re-wrenches.org/ > > There are two list archives for searching. When one doesn't work, try the > other: > https://www.mail-archive.com/[email protected]/ > https://lists.re-wrenches.org/pipermail/re-wrenches_lists.re-wrenches.org/ > > List rules & etiquette: > http://www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > http://www.members.re-wrenches.org >
_______________________________________________ List sponsored by Redwood Alliance Pay optional member dues here: http://re-wrenches.org List Address: [email protected] Change listserver email address & settings: https://lists.re-wrenches.org/mailman/options/re-wrenches_lists.re-wrenches.org/ There are two list archives for searching. When one doesn't work, try the other: https://www.mail-archive.com/[email protected]/ https://lists.re-wrenches.org/pipermail/re-wrenches_lists.re-wrenches.org/ List rules & etiquette: http://www.re-wrenches.org/etiquette.htm Check out or update participant bios: http://www.members.re-wrenches.org
