Posts Tagged ‘Solar’

Operating Our Solar Photovoltaic System!

Friday, October 7th, 2011

PG&E inspected our solar photovoltaic system and installed a bi-directional electric meter so we can be a generator of electricity and send power into the grid.

The following web site shows our electricity production through Enphase’s Envoy reporting system:


Our 'smart meter' that is calibrated accurately in both directions. PG&E installed the meter thi\s afternoon.

Continuing to Work with PG&E

Wednesday, October 5th, 2011

Nothing is easy.  We thought we were there with PG&E and, surprise, we’re not there yet.

We did start to move the control system for our sliding glass doors at the back of the house into the permanent location in the East Storage room.

Yes, it poured rain, starting at ~3:00 am for a couple hours.  Our site handled the rain just fine.

Moving the Door Control System into East Storage Room

When the control system for the three sliding glass doors at the back of the house was set up, we were not ready to mount the control system in its permanent location, which is in the East Storage room.  Now, it is time to do so.

The control system, made by Doors in Motion, requires a dedicated 15 amp circuit and has four wires going from the DC electric motor to the control system, including the switch.  The four wires, which have multiple conductors, are for the power (the transformer to DC and backup battery are housed in the control system), the door switch (open, close, stop, lock, reset), the motion detector, and the encoder unit itself.

We decided to run the wires in a dedicated conduit containing only low-voltage wires.  The conduit is the flexible, orange corregated one-inch conduit by Carlon.  We’ve been obtaining our low voltage products from ADI in Santa Clara.  Hank Malloy and Jordan have been extremely helpful in sourcing the correct products for us.

The conduit included the four wires for the door and the CAT5e wires for the lighting control system (C-bus).  The lighting control system includes a pink CAT5e and a yellow CAT5e.  The pink wire is for the main system and the yellow wire is for a backup (redundant).  All other data CAT6, with a spline, will be blue.

When connecting the wires to the door control system, we found a problem.  Jason Cruz, who installed the door control system, helped Bryan to isolate the problem.  They didn’t solve the problem yet and should complete it tomorrow.

Installing Our Permanent Electric Meter

Although the two-person crew from PG&E installed our permanent electric meter on Monday, October 3, they didn’t have the correct meter for a 400 amp service.  Knowing that the meter would be changed again to a bi-directional meter for our solar photovoltaic generation system, they put in a 200 amp meter.  However, PG&E’s process and internal systems still show our temporary service in place as the correct meter had not been installed.

Thus, PG&E dispatched a meter technician to our job site to install the permanent meter for our 400 amp service.  The meter technician, AJ, smiled as he installed the correct meter saying, ‘I’ll be back in a couple days to install the bi-directional meter that will measure your generation and your electric vehicle consumption.’

We’re just following the process …

Motor for our sliding glass pocket doors at the back of the house. We need to have the wires to connect the control system to the motor in a dedicated conduit.


The path for the flexible conduit will go through the Dining Room, into the soffit and through to the East Storage room.


The one-inch orange conduit will join the two-inch 'smurf' tubes in the soffit going to the East Mechanical room.



The door control system will be located permanently in the wall to the left of the three lighting control system panels.


We're taking the opportunity to install the 1-1/2 inch polyisocyanate insulation against the concrete throughout the lower level (basement). We removed this insulation from the roof and stored it so we could use it again. This insulation will be covered with spray foam, encapsulating it. Note there is two inches of rigid foam insulation outside the concrete wall.


The meter technician from PG&E, AJ, installs the correct Smart Meter for our 400 amp service. This meter replaced the 200 amp meter that was installed on Monday. The next meter that will be installed is the bi-directional smart meter for our solar photovoltaic generation and time-of-use electric vehicle (E-9) rate service.



Installing Our Permanent Electric Meter

Monday, October 3rd, 2011

With our permanent meter in place, we’re a step closer to our rebate.  Every day we seem to get closer …

It rained today and is forecasted to rain through Wednesday.  We are prioritizing our activities to keep our materials dry … bone dry.

Installing Our Permanent Electric Meter

Before we can have an electric meter for our solar generation, we need to have a permanent electric meter in place.  To have a permanent electric meter, we required a ‘meter release’ from the City of Monte Sereno.  The meter release was issued by the City of Monte Sereno on September 29, which was our rebate filing deadline.

Bryan called PG&E several times this morning and learned that our permanent meter was scheduled to be installed on Wednesday, October 5.  Knowing this was delay, Bryan started to call our various contacts at PG&E.  When speaking with the scheduler, Barbara Aker, Bryan explained that if a crew was available at the last minute then we would be ready to have our meter installed.

To our delight, Barbara called and said that a crew came available and they could install our permanent meter today.

Way cool!

Portable Charger for a Nissan LEAF

While getting some parts for Al at Electrical Distributors in San Jose, Bryan noticed a Nissan LEAF in the parking lot.  Bryan spoke with the owner of the LEAF, who explained that he was assembling a portable charging station that could plug into various types of 240 volt circuits.  Further, he explained, the benefit would be to use 240 volt circuits that are available in RV/trailer parks.

For people who buy the LEAF from Arizona used Nissan Dealers, or anywhere else in the country, it can be frustrating not having many charging stations easily available when driving. The portable charging station can fix all of that.

Installing charging stations in RV/trailer parks could be done quickly and easily, which would help deploy the infrastructure for electric vehicles across the U.S.

An interesting idea …

The two-person truck arrived at our job site at ~ 11:30 am this morning.


The service entrance panel had to be secured and then sealed before the meter could go in.


Our permanent meter is in! This meter will be replaced with a 'net meter' that will measure the electricity that we generate and send into the grid.


Charging station that can be used in RV/trailer parks for charging a Nissan LEAF.


Buttoning Up the Ladder in the Vertical Culvert

Friday, September 16th, 2011

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.


Inspecting Our Photovoltaic Solar Panel Installation

Tuesday, September 13th, 2011

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.


Installing the Enphase Inverters

Wednesday, September 7th, 2011

The team from Real Goods Solar completed the racking today, and also installed the remaining 40 Enphase micro-inverters.  They ran wires through the conduit to the East gable, and installed the load center under the North gable.  They did well during a very hot and sunny day.

When Bryan returned to the site after attending an ‘administrative matter’ in downtown San Jose, he was delighted to find that our new aluminum manhole ring and cover were delivered today.  The manhole cover goes over our vertical culvert.

Using Enphase Micro-Inverters

In our original design for our solar photovoltaic panels, we had planned to have two inverters, both located in the East Mechanical room.  After learning more about photovoltaic panels, we decided to use micro-inverters on two of our six arrays, which would have been 16 micro-inverters.  After Jonas Villalba reviewed our installation plans, he recommended that we go to 100% micro-inverters.  The benefit of micro-inverters is that it makes each of the photovoltaic panels in the system independent of the performance of the other photovoltaic panels.

In an array of photovoltaic panels that are connected to a single inverter, the electricity generated is a function of the performance of the photovoltaic panel producing the least amount of electricity.  This means that is one panel is dirty or has degraded performance, for whatever reason, all of the other panels in the array connected to that inverter will have their output reduced.

During the time from the original design to the change to 100% micro-inverters, the cost of micro-inverters dropped.

Thus, we increased the number of Enphase micro-inverters to 48.

Each of these micro-inverters has to be installed individually, which was completed today.

Our Aluminum Manhole Cover

The water from under the foundation goes through a drainage system and ends up in our vertical culvert.  From the vertical culvert, we have two sump pumps (one is redundant) that pump the water up and into our underground cistern.  From the underground cistern, we irrigate our draught-tolerant landscaping.

The vertical culvert is approximately 17 ft deep and has an inside diameter of 36 inches.  We have a ladder that goes inside the vertical culvert for maintenance and servicing of the sump pumps.  The vertical culvert needs a safe and secure cover.  We decided to have Barry Foundry of Birmingham, Alabama manufacture our manhole cover using aluminum.  We chose aluminum to reduce the weight of the manhole cover and to avoid corrosion.

The aluminum manhole cover, and ring, arrived today.

Way cool …


The aluminum manhole cover and ring, sitting on top of the vertical culvert. We need to cut the vertical culvert so the manhole cover is at grade.


The vertical culvert, and aluminum manhole cover, is at the top of the stairs and will be a feature of the house.


The project manager for the on-site work by Real Goods Solar, Bryan McFarland, sets up to pull the first set of conductors through to the array on the East gable roof.


The racks to hold the photovoltaic panels are completed on the Upper Flat roof. The Enphase micro-inverters are installed on the racking system.


The Enphase micro-inverters are being installed on the racking system. Note the Enphase box, which holds 10 micro-inverters.