Since Bob Wise was in the Bay Area today, he had phoned in advance to schedule an inspection.  Bob has been a mentor throughout our construction and has inspected our progress on a regular basis.

Bob lives on Bainbridge Island in a house that he had built a couple years ago.  Bob’s first inspection of our project was on March 12, 2009 and he stood in the Wine Cellar.  Bryan toured Bob’s homes on February 26 and 27, 2010, when Bryan was returning from seeing the 2010 Winter Olympics in Vancouver, Canada.

Recently, Bob advised us on conduit for our low-voltage wiring throughout the house.

It was great to host Bob’s visit.

Bob Wise pushes the button to close the sliding glass doors at the back of the house.

Bob Wise, standing in the Wine Cellar. Very different from the first time Bob stood in the Wine Cellar!

Bob Wise, on the roof, inspecting the solar panels. Nothing like a blue-sky California day to generate electricity!

Darryl returned to Calgary today.  He had arrived from Canada on Friday, September 9 and had visited the job site.

We were pleased to host Uncle D’s visit and were very sad to say goodbye …

Darryl and Kate ...

Nik and Darryl, with the fixed gear bike that Darryl helped Nik to assemble.

We can stroke this one off the list – the ladder inside the vertical culvert is done.  Bryan was at the bottom of the vertical culvert on December 8, 2010.  It feels good to get this element of the project completed.  Finally.

As well, we finished off the solar installation and now we need to get connected to the grid.

Excellent progress …

The ladder and safety post are now mounted securely inside the vertical culvert.

View from the bottom of the vertical culvert (17 feet to the surface).

We put a wooden plywood deck inside the vertical culvert so we could add the electrical and other components safely and quickly.

The cast aluminum ring and manhole cover fit nicely over the vertical culvert.

Panels inside the East Mechanical room ...

Panel open with spacers over deadfront, with labeling. Ready for inspection ...

Our solar permit, which needs to be signed off and closed.

Although we are connected to the grid, this permit should be closed.

Bryan had picked up the Sequoia Vacuum SV-700 unit today and positioned it in the garage.

Initially, we didn’t think that a central vacuum was important. The more we started the learn about the value of indoor air quality, the more we understood the importance of a central vacuum with an external exhaust.

Then, of course, we dug into the cyclonic vs. filter system and determined that we wanted to keep the outside of our house clean.

While evaluating central vacuum systems, we found that the leader in central vacuum systems is Sequoia Vacuum Systems, which is located in Menlo Park, just the other side of Palo Alto.  Earlier, we had worked on installing the collection pipes for the central vacuum system.

IAQ 8.2 Indoor Contaminant Control (1 point each, maximum 2 points).
Select from the following measures:
a) Design and install permanent walk-off mats at each entry that are at least 4 feet in length and allow accessibility for cleaning (e.g., grating with catch basin).
b) Design a shoe removal and storage space near the primary entryway, separated from living areas. This space may not have wall-to-wall carpeting, and it must be large enough to accommodate a bench and at least two pairs of shoes per bedroom.
c) Install a central vacuum system with exhaust to the outdoors. Ensure that the exhaust is not near any ventilation air intake.

Sequoia Vacuum System's SV-700 unit installed in our garage.

The City of Monte Sereno reviewed our photovoltaic solar panel installation and signed off on all the components that Real Goods Solar are responsible for.  The one remaining component is a cover for the 200 amp electrical panel in the East Mechanical room.

Although the cover is required, there is no current flowing through our electrical system as we are not connected to ‘the grid’.

We were honored to have Bob Sobota and Eufermiro Cariaga from Schneider Electric, and Jim Laberty of Lighting Systems tour our project site today.  Bryan met Bob Sobota when Bryan attended the C-Bus training course in Palm Desert in March 2011; Bryan had hosted Jim’s visits to our project site previously, and it was Eric Westphal and Jim that recommended that we engage Randall Whitehead Lighting Solutions to design the lighting throughout the house.  Eufermiro and Bryan met for the first time today.

Bob works in the lighting controls division and Eufermiro is in the Juno Lighting Group.  Jim Laberty is the local distributor for both C-Bus lighting controls and Juno lighting.

Changing Our System to 100% Micro-Inverters

Solar photovoltaic panel installations are new and evolving.  One of the technology elements that is continuing to evolve is the inverter.  Usually, an entire array of panels (or string of arrays of panels) are connected to a single inverter.  The inverter takes the DC and converts it to AC.

For our installation, we changed the design from a mix of one string inverter (for 32 panels) and 16 micro-inverters, to 48 micro-inverters.  Changing to all micro-inverters reduces the conductors (wiring), increases the efficiency of the electricity generation, and increases the safety of the overall system.

One of the challenges with micro-inverters is that not many people understand how these systems work.  Liam Ryan, from Real Goods Solar, explained the details to Bryan.

Before Operating, Micro-Inverters Require a Connection to the Grid

Generally, when solar photovoltaic panels are exposed to sunlight they produce electricity.  The panels create direct current (DC) electricity and that flows to the inverter.  In the case of a micro-inverter, the transmission of DC is only a couple of feet as the micro-inverter is mounted to the panel.  The micro-inverter then creates alternating current (AC) which is connected to the building’s electrical system.

Enphase micro-inverters are ‘UL-listed’ as they have been certified (tested and approved) by Underwriters Laboratories.  Products certified by Underwriters Laboratories are identied with a UL Mark.  According to Underwriters Laboratories’ web site:

The UL Mark on a product means that UL has tested and evaluated representative samples of that product and determined that they meet UL requirements. Under a variety of programs products are periodically checked by UL at the manufacturing facility to make sure they continue to meet UL requirements. The UL Marks may be only used on or in connection with products certified by UL and under the terms of written agreement with UL. In addition to these marks, UL also provides access to the marks required in a number of other key world markets.

Liam explained that the Enphase micro-inverters in our system cannot convert the DC current to AC unless the micro-inverter has recognized the 60 Hz wave form has been stable for five minutes.  The 60 Hz wave form is present in the electrical grid throughout the U.S. and Canada.  Thus, the micro-inverter cannot create AC current unless our system is connected to the grid.

In addition, Liam explained that the micro-inverters will stop creating AC current immediately upon losing recognition of the 60 Hz wave form.  The software in the Enphase micro-inverters is what recognizes the 60 Hz wave forms and then controls the output.

Underwriters Laboratories has certified the Enphase micro-inverters that we are using.

Consequently, although we have our entire solar photovoltaic system built, installed and inspected, we cannot create electricity until we are connected to the grid.  There is no electricity present in our system.

Roseanne Prevost-Morgan and Matt Knobbe of Real Goods Solar dropped by our site to take a quick look at the installation. Bryan, of course, took their picture on the Upper Flat roof.

One of the benefits of the Enphase system is the Enlighten web-based service that shows the status of each solar photovoltaic panel.  Although Liam Ryan completed the initial configuration yesterday, Bryan added some additional details today so the reporting is robust.

Link to Enphase Enlighten System

Our Enphase Enlighten system portal is as follows:

http://enlighten.enphaseenergy.com/public/systems/j8aJ30045

The link above allows us to see the status of each individual panel so we can monitor the performance of the entire system.

Please note that the Enlighten system portal will not be dynamic until the City of Monte Sereno approves our solar installation, which should be on Monday, September 12, 2011 and Pacific Gas & Electric allows our system to be connected to their distribution system.