Another Ground-Mount Fan
I am glad I stumbled on this thread from Poway, and I noticed the similarity to lkstaack's ground array. Both of you attached some great photos of your install progress. My proposed 7.32KW array is also on a slope ( 27 degrees ), however it is reversed ( north slope of Puente Hills ). I know this sounds absurd, but the hillside was terraced in 1929 for an avocado grove, so rather than being a continuous hillside, it consists of 8 flat terraces and 9 (roughly) 45 degree slopes. The trees are long gone, and the slopes have become more rounded, but the terrace I have chosen for my array-site still has a good 15' of level space between slopes. The comparison of the excavating methods used by Poway & lkstaack are particularly of interest to me, as I have been likewise studying both approaches ( hand-dig, machine-trenching, auger-boring ). Unlike the soil conditions in Poway ( granite, decomposed granite ), the soil at my chosen elevation ( 879' AMSL) is designated as Upper Fernando conglomerate; river-washed sandstone & limestone, evenly graded from silt up to 15" boulders ( with an occasional two-footer ).
Using IronRidge's design-assistant, I concluded that my ideal foundation dimension should be 16" diameter x 42" deep. With the larger diameter I should be able to use a two-man gas auger to dig out most of the 8 holes required for the IronRidge pipe foundation. If I encounter a large boulder, I have a 1-1/4" x 6' wrecking bar that should be able to handle it. I am planning on using 16" x 4' Sonotubes to form up the concrete, so I will be able to compensate for any "super holes" that are caused by large rocks. I once contemplated renting a Ditch-Witch trencher to dig out the 95' run from the array to my back walkway, but opted instead for a hand-dig, since I am the "contractor" for the job, am unwilling to run the risk of a "downhill runaway trencher" accident.
I finished surveying the site & setting grade-stakes today, & estimate that I will have to move between 1-1/2 to 2 yards of earth from the back of the terrace to level-out the site.
I am glad I stumbled on this thread from Poway, and I noticed the similarity to lkstaack's ground array. Both of you attached some great photos of your install progress. My proposed 7.32KW array is also on a slope ( 27 degrees ), however it is reversed ( north slope of Puente Hills ). I know this sounds absurd, but the hillside was terraced in 1929 for an avocado grove, so rather than being a continuous hillside, it consists of 8 flat terraces and 9 (roughly) 45 degree slopes. The trees are long gone, and the slopes have become more rounded, but the terrace I have chosen for my array-site still has a good 15' of level space between slopes. The comparison of the excavating methods used by Poway & lkstaack are particularly of interest to me, as I have been likewise studying both approaches ( hand-dig, machine-trenching, auger-boring ). Unlike the soil conditions in Poway ( granite, decomposed granite ), the soil at my chosen elevation ( 879' AMSL) is designated as Upper Fernando conglomerate; river-washed sandstone & limestone, evenly graded from silt up to 15" boulders ( with an occasional two-footer ).
Using IronRidge's design-assistant, I concluded that my ideal foundation dimension should be 16" diameter x 42" deep. With the larger diameter I should be able to use a two-man gas auger to dig out most of the 8 holes required for the IronRidge pipe foundation. If I encounter a large boulder, I have a 1-1/4" x 6' wrecking bar that should be able to handle it. I am planning on using 16" x 4' Sonotubes to form up the concrete, so I will be able to compensate for any "super holes" that are caused by large rocks. I once contemplated renting a Ditch-Witch trencher to dig out the 95' run from the array to my back walkway, but opted instead for a hand-dig, since I am the "contractor" for the job, am unwilling to run the risk of a "downhill runaway trencher" accident.
I finished surveying the site & setting grade-stakes today, & estimate that I will have to move between 1-1/2 to 2 yards of earth from the back of the terrace to level-out the site.
Comment