The installation team from Akeena Solar arrived at the job site this morning to install the mounting system on our upper flat roof. Also, they pulled the ‘fish’ through the conduit to the storage space below the pantry.
At the same time, the two-person team from 88HVAC continued to connect the HDPE in the concrete piers on the West side of the house while Izzy backfilled and compacted the soil over the natural gas and electric conduit.
The week ended on a very positive note.
Installing the Solar Mounts on Our Upper Flat Roof
We worked with Akeena Solar to design our solar system so it would generate as much electricity as possible. The East/West axis of our house is positioned within 13 degrees of due East/West and, on our upper flat roof alone, we have 624 square feet available for solar panels. These factors meet two of the four requirements under LEED-H ID 1.5 Building Orientation for Solar Design.
For our latitude, the solar photovoltaic panels should be at approximately 23 degree tilt to optimize the generation of electricity. Although we could have designed the system to have a single plane of panels then it would have been taller. In addition, solar photovoltaic panels require periodic cleaning to maximize the production of electricity.
Since we had some space, but not sufficient space, on the roof to include walkway space between the four arrays of panels, we ‘terraced’ the arrays. Terracing the arrays provides space between each array (row) of panels while reducing the shading of the panels by the array in front of it.
With the terracing, we required a frame for each array of eight panels. These frames must be raised off the upper flat roof by mounts and these mounts will penetrate the roof membrane. And, the conduit going from each array to the ‘combiner box’ must penetrate the roof membrane.
Duk Lee of Akeena Solar completed the detailed design of the layout and the frames (Sheet PV-1 and Sheet PV-2). The onsite team was given the task to build the system. The first step in building the system was to install the mounts on the upper flat roof and run the conduit on the lower flat roof that will be under the tapered insulation.
Of course, the electrical and structural components of the system need to be inspected by the City of Monte Sereno …
The installation team from Akeena arrived on site as scheduled this morning. They took care to park on Winchester Boulevard so their vehicles did not use any of the precious parking space on Via Sereno. After an orientation and brief tour of the project, they set to work laying out the solar mounts. Later in the morning, Duk Lee arrived to verify the layout was as designed. As well, Ben Caschera, the installation manager with Akeena Solar came to the project site to see how his team was doing.
There were some difficulties with the ‘fish tape’ going through the dedicated conduit that will carry the DC and AC from the roof to the East Mechanical room. No problem. The installation team used a shop vacuum to pull a nylon string attached to a small plastic ‘balloon’ through the conduit. Within minutes, the fish tape was then in place.
At the end of the day, Don Henderson, the senior person on the installation team, called for an inspection for Monday afternoon with the City of Monte Sereno. After ensuring the site was clean and secure, Don called it a week.
Backfilling and Compacting the Trench for Natural Gas and Electricity
Izzy completed the backfilling and compacting of our trench this afternoon. Completing the backfilling created a significant amount of real estate at the front of the property. Also, it made the site much safer and easier to get around. Izzy’s next task was to put the 4 inch pipe in place around the perimeter of the house that will take 100% of the water from the roof to our underground cistern. He got a good start on this today and will finish it by Wednesday.
Connecting the Ground Loops
Justin and Michael from 88HVAC were on site again today. They connected two ground loops in each concrete pier on the West side of the house. Next week they will test the ground loops in each concrete pier for adequate flow and pressure. If that test is OK, then they will connect the concrete piers and bring the complete ground loop inside the house to the West Mechanical room.
Overall, we’re continuing to make progress. And progress is good.