My Broken Solar Panel: Mounting it to the ground
Making the 4 threaded rod attachments
The next step in the experiment with this broken solar panel is to mount it to the ground in my back yard so it can collect sunlight. I'll use threaded rod 3/8 inch diameter to attach the base of the frame to concrete posts. B-Line material of the frame has factory punched holes ready to accept bolts of this size.
Threaded rod is easily obtained at any local home improvement center. They usually have a good selection of various diameters and lengths. I chose 3/8 inch diameter by 3 feet long because it will be cut in half for this project, so I only need to buy two of them.
[ photo of frame with threaded rod installed ]
I'll start by attaching the threaded rods into the four corners of the frame. In the photo above you'll see there is a flat washer attached to the end with two nuts holding it secure. The purpose of the washer is so I can use the frame itself for marking the ground for digging the holes.
[ photo of 4 anchor brackets for the frame ]
After digging is finished, the washers will be replaced with the anchor brackets shown in the photo above. These brackets will be buried deep within the concrete resulting in a very secure bond and they will add some strength as well.
[ photo of frame in place for marking where to dig ]
This photo shows the frame sitting on top of cinder blocks in the location where it will be installed. There are small blocks of wood under each side to precisely level the frame. Leveling is important to get the correct angle to the sun.
[ photo of threaded rod marking the spot to dig ]
I used a metal stake to mark the ground where to dig. We'll move the frame out of the way when we're ready to start digging the holes.
[ photo of fence post hole digger inside one of the holes ]
A fence post hole digger is really the best tool for making nice small round holes in the ground. Since we are installing a single solar panel the hole doesn't have to be very deep. The massive weight of the concrete will do most of the work holding the panel in place while the shallow holes will keep it from wandering.
[ photo of frame back in place ]
When the four holes in the ground are finished we'll set the frame back on top of the cinder blocks to check our work. If all went well the four legs will align with the four holes in the ground. If the legs don't line up with the holes we would have some problems to deal with.
[ photo left end of frame legs alignment with holes ]
[ photo right end of frame legs alignment with holes ]
[ photo right rear leg alignment with hole ]
[ photo close up of right rear leg ]
Now that the holes are finished and the alignment is checked we're OK for the next step, prepare the legs. Remove the washers we used for hole alignment and attach the anchor brackets to the threaded rod as shown here. The anchor brackets will extend almost to the bottom of the hole. This adds steel reinforcement to the concrete post and ensures the threaded rod will remain firmly in place.
[ photo of frame leg with anchor bracket installed ]
[ photo of two frame legs with anchor bracket installed ]
Concrete will fill the holes we dug for the legs but we'll need some concrete forms for above the ground. The base of the mounting frame will sit about 16 inches above ground. We'll use round tube concrete forms about 8 inches in diameter to do this. Home improvement centers have this type of material available in various sizes. I chose the smallest diameter they had, 8 inches, almost too big for this project.
[ photo of 8 inch diameter concrete form tube ]
One concrete form tube is 4 feet long. Instead of buying more of them to get 16 inches, we'll cut them into 12 inch lengths and make up the difference in height another way. We'll use a little less concrete because of this too.
[ photo of form tube after cut to length ]
I used a tape measure to mark one foot lengths around the diameter, then a battery operated circular saw to cut the cardboard tube. It is fairly thick material so a utility knife just won't do the job. For the next step a utility knife or scissors will clean up the ragged edges left by the circular saw.
[ photo of form tubes in place outside ]
Sometimes the best plans run into a snag and make you think, "why didn't I see that before?" In the photo above the form closest to the camera looks different than the others. That's because the length came up a little short due to a slope in the ground. Yeah, it's pretty subtle and I didn't see it until now.
To make all four tubes end at the same height below the solar panel mounting frame I had to extend the length of that one tube about 3 inches. I cut two strips from a heavy cardboard box and taped them to one end of the concrete form tube. Lots of 2 inch wide shipping tape! When concrete is poured into the form it will be very wet. Cardboard gets soggy when it gets wet. So, lots of tape...
[ photo of concrete pouring tools ]
Here are the tools we need to pour concrete into the forms. The solar panel mounting frame is in place and leveled up. The legs are centered in the form tubes as best as possible. The form tubes are sitting straight up and down as possible. Ready for the concrete.
I'll use the small shovel in the foreground to transfer the concrete from the wheelbarrow into the form tubes. The straight copper tube with closed off end will be used to settle the concrete by tamping it down as the tube fills up. This has the effect of removing trapped air in the concrete which would otherwise leave empty spaces when it cures. The trowel will be used for the finishing touches on the top surface of the concrete to make it smooth to look nice.
[ photo of wheelbarrow and hoe ]
Mixing concrete one bag at a time is fairly easy with a garden hoe and a wheelbarrow. The garden hose in the previous photo is the water supply for this process. In the past I've tried measuring water in a bucket to mix concrete but it didn't seem to be the right consistency. Now I just spray the hose into the wheelbarrow, stir with the hoe, and repeat until it's just right. Somewhere between clumpy and runny is the sweet spot. If a clump from a shovel full can stand on its own with out flattening too much, that's the spot.
[ photo of first hole filled with concrete ]
We want to fill the hole a little at a time, then use the tamping pole to settle the concrete. A few more shovel fulls then tamp again. Yeah, you can probably tell there's a story behind this procedure. I didn't do this when I installed the big system that powers my home. And yes, there were air gaps in the poured concrete. Some of them appeared when I removed the cardboard form tubes after the concrete dried. Doesn't look very nice but it works OK.
[ photo of right end with bubble level ]
[ photo from rear showing all four concrete posts ]
Well that's it. Now we wait for the concrete to dry.
The next step is to mount the solar panel to the frame, wire it up, and attach it to the battery bank.
Gregg Scholfield 2-13-2013
[ photo of frame with threaded rod installed ]
I'll start by attaching the threaded rods into the four corners of the frame. In the photo above you'll see there is a flat washer attached to the end with two nuts holding it secure. The purpose of the washer is so I can use the frame itself for marking the ground for digging the holes.
[ photo of 4 anchor brackets for the frame ]
After digging is finished, the washers will be replaced with the anchor brackets shown in the photo above. These brackets will be buried deep within the concrete resulting in a very secure bond and they will add some strength as well.
Set the frame in place to mark post holes
[ photo of frame in place for marking where to dig ]
This photo shows the frame sitting on top of cinder blocks in the location where it will be installed. There are small blocks of wood under each side to precisely level the frame. Leveling is important to get the correct angle to the sun.
[ photo of threaded rod marking the spot to dig ]
I used a metal stake to mark the ground where to dig. We'll move the frame out of the way when we're ready to start digging the holes.
And now we'll start digging the post holes
[ photo of fence post hole digger inside one of the holes ]
A fence post hole digger is really the best tool for making nice small round holes in the ground. Since we are installing a single solar panel the hole doesn't have to be very deep. The massive weight of the concrete will do most of the work holding the panel in place while the shallow holes will keep it from wandering.
[ photo of frame back in place ]
When the four holes in the ground are finished we'll set the frame back on top of the cinder blocks to check our work. If all went well the four legs will align with the four holes in the ground. If the legs don't line up with the holes we would have some problems to deal with.
[ photo left end of frame legs alignment with holes ]
[ photo right end of frame legs alignment with holes ]
[ photo right rear leg alignment with hole ]
[ photo close up of right rear leg ]
Install the anchor brackets on the legs
[ photo of frame leg with anchor bracket installed ]
[ photo of two frame legs with anchor bracket installed ]
Prepare concrete forms for the legs
Concrete will fill the holes we dug for the legs but we'll need some concrete forms for above the ground. The base of the mounting frame will sit about 16 inches above ground. We'll use round tube concrete forms about 8 inches in diameter to do this. Home improvement centers have this type of material available in various sizes. I chose the smallest diameter they had, 8 inches, almost too big for this project.
[ photo of 8 inch diameter concrete form tube ]
One concrete form tube is 4 feet long. Instead of buying more of them to get 16 inches, we'll cut them into 12 inch lengths and make up the difference in height another way. We'll use a little less concrete because of this too.
[ photo of form tube after cut to length ]
I used a tape measure to mark one foot lengths around the diameter, then a battery operated circular saw to cut the cardboard tube. It is fairly thick material so a utility knife just won't do the job. For the next step a utility knife or scissors will clean up the ragged edges left by the circular saw.
[ photo of form tubes in place outside ]
Sometimes the best plans run into a snag and make you think, "why didn't I see that before?" In the photo above the form closest to the camera looks different than the others. That's because the length came up a little short due to a slope in the ground. Yeah, it's pretty subtle and I didn't see it until now.
To make all four tubes end at the same height below the solar panel mounting frame I had to extend the length of that one tube about 3 inches. I cut two strips from a heavy cardboard box and taped them to one end of the concrete form tube. Lots of 2 inch wide shipping tape! When concrete is poured into the form it will be very wet. Cardboard gets soggy when it gets wet. So, lots of tape...
And now let's pour the concrete
[ photo of concrete pouring tools ]
Here are the tools we need to pour concrete into the forms. The solar panel mounting frame is in place and leveled up. The legs are centered in the form tubes as best as possible. The form tubes are sitting straight up and down as possible. Ready for the concrete.
I'll use the small shovel in the foreground to transfer the concrete from the wheelbarrow into the form tubes. The straight copper tube with closed off end will be used to settle the concrete by tamping it down as the tube fills up. This has the effect of removing trapped air in the concrete which would otherwise leave empty spaces when it cures. The trowel will be used for the finishing touches on the top surface of the concrete to make it smooth to look nice.
[ photo of wheelbarrow and hoe ]
Mixing concrete one bag at a time is fairly easy with a garden hoe and a wheelbarrow. The garden hose in the previous photo is the water supply for this process. In the past I've tried measuring water in a bucket to mix concrete but it didn't seem to be the right consistency. Now I just spray the hose into the wheelbarrow, stir with the hoe, and repeat until it's just right. Somewhere between clumpy and runny is the sweet spot. If a clump from a shovel full can stand on its own with out flattening too much, that's the spot.
[ photo of first hole filled with concrete ]
We want to fill the hole a little at a time, then use the tamping pole to settle the concrete. A few more shovel fulls then tamp again. Yeah, you can probably tell there's a story behind this procedure. I didn't do this when I installed the big system that powers my home. And yes, there were air gaps in the poured concrete. Some of them appeared when I removed the cardboard form tubes after the concrete dried. Doesn't look very nice but it works OK.
[ photo of right end with bubble level ]
[ photo from rear showing all four concrete posts ]
Well that's it. Now we wait for the concrete to dry.
The next step is to mount the solar panel to the frame, wire it up, and attach it to the battery bank.
Gregg Scholfield 2-13-2013
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