This week, I’m sharing all of the details on our solar panel project. For the first post, click here.
When we last left off, we finally had an approved application, and we’d made it through a wicked winter. But we were running out of time to complete our panels by the end of our contract.
The first step to get ready for the install was an engineering assessment. We had to make sure that the barn was strong enough to hold the weight of the solar panels. Even though the barn is (at best guess) more than a hundred years old, it’s rock solid, so there was no concern there.
The second step was the building permit. Again, there were a couple wrinkles in the application paperwork, but our contractor was able to straighten them out
The actual solar install finally started at the end of March. First step was the inverters. These “convert the DC (Direct Current) power from your panels to AC (Alternating Current) before feeding it back into the hydro grid.” Our contractor’s web site calls the inverters “the brains” of the system.
Then came the panels. Solar panels work best if they face south. The sun is strongest and hits them most directly from this direction. Fortunately, the back roof of the barn faces exactly south. Given the long delay in our application process, we had lots of time to observe the barn, calculate sun and shadow patterns and determine the optimum position for our panels. We have a long row of very tall pines along the west side of the barn. They’re so tall that in the late afternoon they cast a shadow on the upper barn roof, so we decided to install the panels on the lower lean-to roof as far away from the pines as possible.
Three rows of racks went up on the lean-to, and then came the panels. We have a total of 40 panels, the maximum we’re allowed under the microFIT program. Panel install took about three days.
After the last panel was installed, it took another two weeks before the snow had melted enough for the trench to be dug between the barn and the hydro pole. Remember we’re feeding all of the power we generate back into the grid, so connecting into the hydro pole was essential.
Of course, it wasn’t simply a matter of waiting for the snow and frost to melt so that the trench could be dug. The trench was more than 300 feet long. Over that distance, we needed a special heavy-duty type of wire, so that we didn’t lose power. Pulling the wire through the trench was another bit of fun. When the trench was dug, the excavator laid a conduit in the bottom. It looks a bit like weeping tile.
There’s a rope running through the pipe. The trench is back-filled and the conduit is completely buried. To get the wire from the panels to the pole, our contractor had to pull it using the rope in the conduit–a heavy, 3-person job.
April 23 was connection day. Inspections had to happen. Power had to be shut off. Wires had to be hooked up. And everything had to be turned back on again. There were two or three different groups involved, along with our contractor. This was another instance where I was very glad for professional help. I would not have wanted to coordinate everyone.
But it turned out all of the scheduling didn’t matter.
Connection was a no-go. The hydro inspector wanted to see the wire and conduit laying in the trench, but the trench was back-filled. The excavator had installed a T with a small section of conduit that looked down to the bottom of the trench and the wire, but that wasn’t enough. A section of the trench had to be dug out down to the wire so that the inspector could see it. Fortunately, the trench was re-excavated April 23, and by April 24 we were connected.
April 25, our contractor came out and walked us through all of the equipment and how it worked. He flipped the breakers and we were live.
In the infamous words of Snap, I’ve got the power!