Installing the Solar Mounts on Our Upper Flat Roof

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.

A non-terraced set of four arrays of solar panels would be taller than a terraced set and not allow easy access for cleaning the solar photovoltaic panels.

A non-terraced set of four arrays of solar panels would be taller than a terraced set and not allow easy access for cleaning the solar photovoltaic panels.

Terracing the set of four arrays lowers the overall height but requires more area for the panels. The wider the spacing between each array lowers the height of each subsequent array (the shading angle is 23 degrees for our latitude).

Terracing the set of four arrays lowers the overall height but requires more area for the panels. The wider the spacing between each array lowers the height of each subsequent array (the shading angle is 23 degrees for our latitude).

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.

Detailed design on the mounts and frame for the arrays on the upper flat roof.

Detailed design on the mounts and frame for the arrays on the upper flat roof.

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.

Starting to lay out where the mounts will be located on the upper flat roof. The cool night resulting in very heavy condensation on the newly Tyveked roof.

Starting to lay out where the mounts will be located on the upper flat roof. The cool night resulting in very heavy condensation on the newly Tyveked roof.

Izzy was backfilling and compacting the trench for the natural gas and underground electric conduit.

Izzy was backfilling and compacting the trench for the natural gas and underground electric conduit.

The team from Akeena Solar installs the mounts on the upper flat roof. It was a beautiful, blue-sky California day (again).

The team from Akeena Solar installs the mounts on the upper flat roof. It was a beautiful, blue-sky California day (again).

The acorn nuts can now be covered with the tapered foam insulation such that the member will not be damaged over time.

The acorn nuts can now be covered with the tapered foam insulation such that the member will not be damaged over time.

Don Henderson, from Akeena Solar, on the upper flat roof.

Don Henderson, from Akeena Solar, in an animated telephone conversation on our upper flat roof.

Conduit that will take the AC lines from the North gable roof to the East Mechanical room.

Conduit that will take the AC lines from the North gable roof to the East Mechanical room.

Don reviews progress.

Don reviews progress.

The solar mounts are looking good! The tapered insulation will cover the solar mounts.

The solar mounts are looking good! The tapered insulation will cover the solar mounts.

Don Henderson calls it a day. And a week. The team from Akeena Solar will be back on Monday to finish the last items and then the City of Monte Sereno will inspect the progress on Monday afternoon.

Don Henderson calls it a day. And a week. The team from Akeena Solar will be back on Monday to finish the last items and then the City of Monte Sereno will inspect the progress on Monday afternoon.

Other than the location for the new electric service box, the trench with the natural gas and electric is backfilled and compacted. The pile of dirt is much smaller now!

Other than the location for the new electric service box, the trench with the natural gas and electric is backfilled and compacted. The pile of dirt is much smaller now!

After taking the flag down, Bryan smiled and took one last picture of the solar mounts on the upper flat roof.

After taking the flag down, Bryan smiled and took one last picture of the solar mounts on the upper flat roof.

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