EnergyBible Headquarters Goes Solar
The home/office headquarters of EnergyBible.com recently installed
a new renewable energy system, a 5 Kilowatt photovoltaic solar system.
In this article we describe in detail the build out process day-by-day
as it happened. By sharing this
experience we are hoping we can help other business and home owners
get a real sense of what it is like to have a solar system installed.
It should be noted up front that in our case we built a brand new
porch and put the solar system on it. For most homeowners there
would be no need to do any construction if the solar panels are going
to be placed on an existing roof or surface.
Getting an Estimate
When we originally envisioned putting in a solar PV system we had
planned to do all of the work ourselves. However, when we moved
to California we found ourselves in a place where, unlike our old town
in New York, there were contractors with extensive local experience in
doing solar PV systems. Moreover, being new to the area, we
didn't know the local building regulations nor did we have experience
in processing the paperwork for the solar incentives the state of
California requires. Given this we decided to contract out the
project, rather than build it ourselves.
The first step in the process of contracting a solar system is to get
bids from reputable local solar providers. In many communities
there are several local solar contractors which are listed in the
yellow pages or on the Web. By far the best site to go to when
you want to find a solar professional is
http://www.findsolar.com/.
This site, which is supported by the American Solar Energy Society (ASES),
maintains an excellent database of solar contractors throughout the
U.S. for both residential and business installations. By typing
in your area code you can get a listing of all of the solar
contractors in your area and background on each contractor. To
start our project we did a search using this site and selected 3
contractors from the list to get bids from. One contractor, AM
SunPower we were already familiar with (they had done work for our
relatives) and the other two were new to us.
July 7, 2009 - Meeting with Contractor One
 The first contractor we got a
bid from (we won't mention the contractor name since they were not
ultimately selected) came out on a sunny afternoon in July. We
immediately went out to the back yard and showed the contractor the
area. We then discussed the various possibilities for placing the solar
panels. Our original thought was to mount the solar panels on a
porch. We were planning to add a porch to the house anyway
because it had far too much sun exposure to the windows on the south
facing side which made the kitchen too hot. The contractor agreed that a porch would work well as a mounting structure
and also noted that it would provide more surface area for mounting
than our roof would which was great because we wanted to put in enough
panels to completely cover our entire electric bill.
The contractor had brought with him a device called a Pathfinder
which solar professionals use to measure sun direction and shading.
His conclusion was that the location would be excellent. It was
only a few degrees off of true south which is optimal for solar panel
placement and there was almost no shading.
We had a number of questions built up and the contractor did an
excellent job of handling them. One thing that concerned us was
the time required for getting permits. Our relatives on the coast had
been forced to wait six months for approval on their system and we
were worried it would be a long wait. He assured us that the
town we lived in, Paso Robles, was very solar friendly and always very
prompt about granting permits. Another question we had was in
terms of placement of the inverter. The contractor looked at our
breaker panels and suggested hooking to a subpanel on the side of the
garage rather to the main panel which was in the laundry room.
This made a lot of sense in that there would eliminate the need to
drill through internal walls.
We discussed with the contractor what size of system we would need
and the type of panels. We had thought of possibly going with
two sided panels given that it was going to be a porch but the
contractor was concerned about the cost. The two sided panels
have glass on both sides and as a result are about 20-30% more
efficient. However, they are a relatively new innovation and
cost a bit more so there was a question as to whether or not this
would really save money. This contractor was partial to Sanyo
panels and strongly recommended them for the project. Overall we
were pleased with the review and the contractor assured us that they
could do the project.
July 9, 2009 - Meeting with Contractor Two
The second contractor we called was a company called AM SunPower.
The estimator who came out was Mark Miller. When Mark came out
we followed pretty much the same process. We went out to the
back yard and showed him what we had in mind. We made it clear that we
wanted to go with a big enough system to cover our entire electric
bill. The challenge we had was that, having just purchased the
house, we had very little baseline to work from as to what our
electric bills were going to be. We
thought we might be able to get usage history from our electric
provider, PG&E, but given that the house had been rented to several
people prior to our buying it we weren't sure that would tell us much.
Mark informed us that he had done other projects in the neighborhood
and might be able to get us usage data from other homes in the area.
One of the advantages of using a local contractor is that they may
have already done work in your neighborhood and have a good sense of
local energy costs.
 We discussed with Mark what our electric usage requirements would be.
In California air conditioning is by far the greatest draw on
electricity. We noted that we had central air with two condenser
units and two cooling zones. We also noted that the attic had
been insulated with a radiant barrier which can greatly reduce the
demand for cooling. We went over the various appliances in the house
and noted that all of the main appliances were Energy Star rated.
Since solar systems last a long time (25-30 years minimum) it was
important also to discuss future plans which might further increase
our electric use. We noted that we were planning in the future
to get a freezer and perhaps a hot tub, it is California after all!
That was about it. Later it hit us that we should probably have
thought about planning for electric cars which we want to eventually
switch to but you can't think of everything! Based on the
discussion we settled on a 5 Kilowatt system as a target.
Once we had discussed what we were looking for and our energy
requirements Mark then took some measurements using a solar Pathfinder
just as the first contractor had done. He confirmed that the porch would be just a few degrees off of true south
which meant that it would receive excellent sun during the day. The
device that Mark used was a little bit different than the other
contractor had used in that it
took a panorama of photographs so that it could show any potential
obstructions which would shade the solar panels. Later we
learned this was a requirement for submitting a request for the
financial incentives for solar systems in California. Solar
panels can be strongly effected by shade and so this was an essential
consideration. Because we were at the top of a hill there were no
trees or other obstructions that would have any impact on the solar
panels .
Once Mark had finished making these measurements we sat down with
him and discussed the potential timeline for the project. We
went over a potential time line and what the steps in the build out
would be. Like the prior contractor, Mark assured us that the Paso
Robles area was "solar friendly" and the waiting time should not be
more than a few weeks for a permit. He then told us he would be
back with a bid within a week.
July 18, 2009 - The Winning Bid
We received the two bids in about a week and reviewed them
carefully. Both bids were carefully prepared and reasonable.
After much consideration we decided to go with the one from A.M.
SunPower.
There were several things we liked about their bid. First,
they had done a good job of setting out the financial considerations
in clear language including explaining the impact of the California
and Federal solar incentives. They also charted for us the
payback point so it was clear how long it would take for the system to
pay for itself. Any such estimates are at best educated guesses
because they all depend upon on how accurately you can forecast the
price of electricity for the next 25 years (solar panels last a long
time!). Based on a conservative estimate that electric rates
will continue to rise in California at 5.9% per year the system should
have paid for itself and for the porch in about 10 years. They also
showed the payback data both with financing and without financing.
We ultimately decided to finance the system ourselves but it was nice
to see the payback comparison. I think the final deciding factor was
the design of the porch itself. We were looking for something
simple and maybe a bit western or Spanish looking. They designed a
porch that had that kind of feel and was exactly what we were looking
for.
The system they proposed was a pretty straightforward grid-tied
system. The recommended the following hardware configuration:
- System Size:
4620 Watts DC
- Solar Panels:
Sunpower 210 Watt panels
- Number of Panels:
22
- Inverter:
Sunpower 4000 watt, SPR4000m
- Array Square Footage:
3000 square feet
- Mounting System:
Smart Mount Roof Mount
- Monitoring System:
Sunpower Wireless/Internet
The SunPower solar panels seemed like a good fit. SunPower is a
major panel manufacturer and these particular panels had a very high
efficiency rating, 16.9%. Anything over 15% is generally very
good efficiency. The panels also have a good temperature
coefficient which is important out here in California where the
temperatures are high. Excessive heat can reduce a solar panel's
efficiency and these panels would compensate well for that.
However, as we looked at the porch design we noted that the panels
didn't quite cover the porch end to end. After some discussion
on the aesthetics we decided to add 2 more panels to bring the total
to 24. This added a little cost but also provided us with a
little more energy output which we figure is a good thing,
particularly once we add the hot tub! The additional panels also
necessitated a bit bigger inverter but we were comfortable with that
because it is better to have a slightly bigger inverter than what you
need so you are never having to push it to its full capacity thus
increasing its lifetime.
Once we had made these adjustments the estimate was adjusted and we
had our final numbers. Here is what the financials looked like:
- Total Cost:
$48,432
- California Rebate at $1.50 per Watt:
$6,880
- Cost After Rebate:
$41,551
-
- Tax Credit Calculation:
- After Rebate Cost:
$41,551
- Tax Credit Rate:
30%
- Estimated Tax Credit:
$12,465
- Cost After Tax Credit: $29,086
You can see from this data that the both the California and Federal Incentives have a huge impact on the cost of the system. It reduce the cost of the solar system by almost 40%.
We had waited a bit on putting in the solar system when we moved to
California because we were afraid the Federal tax incentives were
going to expire. Fortunately under the new administration the
incentives were renewed and improved so that rather than just having a
capped $3000 exemption you could take a full 30% off your taxes.
Since we were in a high tax bracket this should make a very big
difference in our taxes this year.
Once we had made the adjustments on the original proposal Mark sent
us out an updated proposal, we signed it and were on our way.
Over the next few weeks A.M. SunPower sent us a few forms to sign
including an application for a local building permit.
Tuesday - August 4, 2009 - The Work Begins
 Today was the first day of actual construction and as you would
expect it was pretty much about basics. Two trucks from A.M.
Sunpower showed up around 10:00 AM. There were three crew
members, Cory Howe, who was the Director of Installations and two
installers, Auston Taber and D.C. Summers.
The house is a pretty typical
California suburban home with stucco walls and a concrete tile roof.
The south side has two windows and a large patio door which lets in a
lot of sun during the summer necessitating a significant amount of air
conditioning. The plan is for the new solar porch to cover the entire
length of the back of the house which will shade the windows and
should help reduce our air conditioning use even before we put in the solar panels.
 The team immediately went to work measuring the area where the
porch would go and laying out the lines for the foundation. They
used snap lines and fluorescent orange paint to mark where the posts
would go for the porch foundation. Once the post hole points were
marked they began digging the holes for the posts, down to about 30
inches. I am sure this came as a surprise to our local gophers who
pretty much feel they own our back yard. Once the wholes
were dug for the posts the installers began building simple square
frames for the post foundation. Once the frames were all in place the
team called it a day given that the sun was reaching its usual 90
something degrees. Tomorrow they will return and begin pouring the
concrete foundation.
Wednesday - August 5, 2009 - A Strong Foundation
 The A.M. Sunpower team was back this morning to finish off the post
foundations for the porch. First they added in a metal
post frame made of galvanized steel. This will make it easy to
attach the posts to the foundation. Then they mixed up the
concrete in a wheelbarrow and poured it into the foundations they had
made yesterday. We had to joke that this picture was a
construction classic. Two guys standing around while one guy
does all the work :) Still, I suspect having two guys pour the
concrete probably wouldn't add a lot of value.
Soon after pouring the post foundations the wood for our porch
showed up. The wood is Douglass Fir and has already been pre-cut
including the end pieces. Once we got a look at the wood we
debated whether to leave it natural, stain it, or paint it to match
the wood trim. After much discussion we decided to match it to
the trim rather than stain it. The team will do that painting next
week. That was about it for today, but here is a look at the poured
posts still in their frame. It will take several days for the
cement to dry so the crew won't be back until Monday.
Monday - August 10, 2009 - Setting the Posts
 By Monday the concrete post foundations had been given adequate
time to dry and so the wood bracing was removed. The main task
for today was priming all of the wood for the porch. The full team was
out, paint rollers in hand, and got most of the wood primed.
They also began the job of setting up the base board where the porch
will connect with the house. Once the base board was put up the
team put in brackets that will hold the main beams for the porch.
This picture of them putting up one of the porch posts has a certain
Washington Monument feel to it don't you think!
Tuesday - August 11, 2009 - Building the Porch Frame
 Today the porch began to rise. The A.M. SunPower team began
raising the posts for the porch. The post rested on the foundations
that had been put in earlier. The picture below shows them
putting up the cross beams By the end of the day all of the main posts had been put it.
They also finished the last of the priming.
Wednesday - August 12, 2009 - Finishing the Frame
The porch, or to be more precise, the "raised solar array" really
began to take shape today. The team put up the cross beams so
that the basic framework of the porch was complete. It really
looked a lot bigger that we imagined once the framework was up.
We loved the way it framed the view of the valley. The team also
began doing some trenching to set up the electrical. The
electricity coming off of the solar array will be run around the
corner along the side of the house to a sub-panel where it will be
connected with the inverter. Part of the electrical wiring will
be run through conduit on the wall and part of it will be buried.
Today the team dug the trenches for the part which will be buried.
Thursday - August 13, 2009 - Putting on the Lathe and the Rails
The porch is nearly complete. The frame was completed
yesterday and today the team began putting up the lath crosspieces
that provide the shade. They also began putting on the final
coat of pain which will match the trim of the house. Towards the
end they started embedding the solar mounting rails that will hold the
panels. The rails are aluminum and we were pleased with how well
they blended with the lathwork. Next step, putting up the
inverter.
Tuesday - August 18, 2009 - In with the Inverter
 For the last two weeks all of the effort has pretty much been
around building the porch (raised solar array) which will hold the
solar panels. But there really hasn't been any work on the solar
components. Today though, one of the most critical solar
components, a 5 kilowatt inverter, was installed. Almost all PV
systems require an inverter. The reason is that the electricity
coming off of your solar panels is in a form of current known as
direct current (DC) but the electricity which you use in your
house and on the electrical grid is alternating current (AC).
The purpose of the inverter is to convert the DC current into AC
current which your home and the grid both use.
Inverters can be designed to be installed either inside or outside
and all are encased in a weatherproof box to protect the electrical
components. Usually the inverter is located near your main
electric panel (fuse box) or electric meter. In our case the
electric meter was located on the side of the house not too far from
the porch. There was also a subpanel by it which held breakers
for the air conditioning unit. This was great because it had
room for adding additional breakers for the solar system. For our installation we went with a 5 kilowatt
SunPower Model SPR-4000m inverter. Inverters have to be sized properly
to your system. In our installation we will be installing 3 strings of
8 solar panels. Each panel generates about 47 volts of current
so the combined voltage for 8 panels wired in serial is 376 volts.
The inverter is designed to handle input voltage in the range of
250-480 volts so that is well within the range of what we need it to
handle.
 Once the inverter was
installed the lines were run from the inverter to the sub-panel as
seen in the picture above. Two more fuses were added to the
sub-panel for the power coming in from the inverter. The inverter also has a number of overcurrent
protection devices (fuses) which will prevent any overloading from the
solar panel themselves. It also
comes with a combined DC and AC disconnect. This device allows all of the
electricity coming from the solar panels to be disconnected from your
home circuit. This is a safety consideration so that the power company
can work on your lines without danger during an outage. Most building codes
and/or power companies require this functionality.
The inverter comes with a small digital readout which will
provide information on how much power your solar panels are
generating. In our case we have decided to use a separate
wireless monitor which will allow us to monitor the power output from
our solar panels remotely but we can always look at the box itself as
well. The wireless monitoring systems are a common new feature
for solar systems. They cost a little bit extra but make it very
convenient to track how your system is doing. The SunPower
Monitoring System enables us to monitor our system either from a
remote LCD display which we can put anywhere in the house, or from the
Internet. We think it is going to be cool just to pop on the Web and
see what kind of performance we are getting from our solar system.
Thursday - August 20, 2009 - The Solar Panels Go Up
Today was a very big day for our project. Today we began
putting up the solar panels. The panels we are using for our
project are SunPower 210 Watt black panels. These panels have a
number of nice features. They are rated at 16.9% efficient which
means they convert a very significant percentage of the sun's light to
electrical energy. This is a critical feature you want to look
for in any solar panel. The panel also has a reduced
voltage-temperature coefficient which means that these panels tend to
hold up well under high temperatures. That was an important
feature given that the summer temperatures in Paso Robles can get well
over 100 degrees. The panels also are much darker than some and
come with a black frame. This gave the whole array a very
polished look which matched well with the porch.
 The panels were laid across the porch in two
rows of 12 panels each for a total of 24 panels. This made a
nice clean rectangle. We left room for an additional row should
we ever decide to increase our capacity later. From a wiring
standpoint the panels were connected into 3 serial strings of 8 panels
each. We could have wired them as two series of 12 but by doing
it in 3 strings the voltage is lower. Each panel generates 40
volts and when they are wired in a series (positive to negative) the
voltage adds up. By doing a string of 8 panels at 40 volts per
panel the total voltage
comes to 320 volts which is well within the input range of our
inverter.
After all the work in building the porch and putting up the rack
for the panels it was surprising how fast the panels went up on the
roof. Every solar panel has a connection point called a junction
box where the positive and negative leads are connected. Modern
panels come with leads which have simple snap-on plugs for making the
connection to the next panel. You simply snap the panels
together somewhat like building blocks and set them in the rack.
It couldn't be simpler.
As the panels were being put together the team took care to bury
most of the wiring into the racks used to hold the panels. This
make for a much neater look . Since the rack was sitting on a
lathe type of structure the bottom of the panels could be seen from
the porch and by putting the wires into the rack frame (which it is
designed for) the overall appearance is kept quite clean.
By the end of the day most of the solar panels were up and
connected together but not yet connected to the inverter.
Friday - August 21, 2009 - We Generate Electricity!
 The team came back today and completed the installation of the
final solar panels. Once this was done the next step was to
connect the wires from each string of panels to the inverter on the
side of the house. The metal conduit for the wire had already
been laid so it was primarily a process of connecting up the wiring at
each end of the conduit.
Once this was done the lead installer ran a series of tests on the
inverter to ensure that the output from the inverter was reading
properly. Even though it was later in the afternoon and the sun
was no longer at peak by the time they finished the panels were
already putting out 2 kilowatts of energy. It was even more fun
to look at our electric meter and see it turning backwards,
showing us that we were generating more energy than we were using.
This ability to create excess energy and feed it back to the grid and
get paid for it is the essence of the net metering program.
The whole idea is to size your system properly so that by the end of
the year you have put in as much energy as you have taken out.
When that happens your electric bill (except for the unfortunate
hook-up fees) goes away.
Monday - August 24, 2009
Today the team came back and began doing the last of the electrical
hookups, they added an additional unit next to the inverter which
houses the wireless transmitter for the inverter. The SunPower
wireless monitoring system will send the status of the system as read
by the inverter to both a wireless monitoring unit and to the wireless
network which EB uses.
The wall monitor, shown in this picture, is a small unit about 4 x
8 inches which you can hang on any wall you choose since it is
wireless. This allows us to constantly monitor the
output of our system on the Web whenever we want to. The monitor
will track throughout the day the number of kilowatt hours you are
generating with your system in total and per hour. By tapping
the monitor it will shift to additional views of your energy data
including an estimate of how many pounds of pollution you are
offsetting by having a solar energy system. I think of it as a
fun reminder that the system is doing something each day to protect
the environment.
All of this same data is available through the Web interface.
However, one thing which the Web interface provides which the wall
monitor does not is a set of charts and graphs which show you the cumulative output of your system by day, month
and year. Here is a sample of one of the charts from the Website
which shows the hourly output of our system for a single day.
Inspections
The next phase of work will involve a series of inspections.
First, the AM SunPower team will do a complete review of the system.
Then the San Luis Obispo county electrical inspectors must review the
whole system installation and bless it. Finally, PG&E, the
California electric utility must inspect the system. This
inspection is key in that the Net Metering agreement does not go into
effect until they have reviewed the installation. Also, at that time
PG&E will install a wireless digital time-of-day meter. In
California the rates you both pay (and if you are producer receive)
for kilowatt hours of electricity vary by the time of day. The
energy costs more during peak day hours because that is when
electrical demand is usually the highest because of air conditioning
loads. This type of billing is great if you have a solar system
because as an energy producer you are being paid more for the energy
you are putting on to the grid.
Another feature of these types of meters is that the utility can
monitor your energy usage remotely and in some cases use them to
manage your system. For example, during an electrical emergency
the utility can automatically disconnect your system while repairs are
being done. This type of monitoring capability of the
"smart-grid" features you may have heard of recently. The
ability for the utility company to remotely monitor and control energy
usage is key to the smart grid approach.
Conclusions on our Project
As mentioned at the beginning of this article, the build out of our
solar system at EB is probably not typical of what most homeowners
would experience in that we both built a porch and put the array on
it. For most homeowners the majority of the work we undertook to
build a fixed array would not be necessary. Most homeowners
already have a place where they can mount solar panels, either on the
roof or somewhere in their yard. That being said, there are some
things about our project that are really quite typical.
First, the tools needed to determine if your home or business has
the right orientation for solar have become quite sophisticated.
They can not only determine the shading you are likely to encounter
throughout the year, they can take photographs which show you
graphically all of the shading issues you might encounter. This
is critically important because shading can have a disproportionately
large impact on the performance of solar panels.
Another observation we had was in how simple the installation of
the panels has become. The panels all now come with
multi-junction boxes which allow you to simply snap together the leads
from one panel to another. The racks for holding the panels are
also simple to use and as a result the whole process of putting in all
24 panels took relatively little more than a day. This means
that the installation is not only simpler but likely to be much more
trouble free. The new technologies make it hard to do anything wrong.
We were impressed by how much the use of wireless technologies has
improved the consumer's ability to monitor their system. The
wireless package that came with our SunPower inverter was impressive.
It allowed us to have a remote monitor we could put anywhere in the
house and also allowed us to hook our system data directly to our
wireless home network. There is just something very cool about
being able to log on to the Web and see exactly what power your system
has generated each day. We think this ability to really know
what is going on with your system will make them more popular and far
easier to troubleshoot, not that we have had any trouble to shoot.
Finally, we would not be doing justice to our partner in this
project, A.M. SunPower, if we did not mention that having a reliable
solar contractor can make all of the difference. We were
extremely pleased by the quality of the work they did and how easy
they were to work with. They always showed up when they said
they would and were extremely easy to work with. They took time
to explain what they were doing at each step. We were also
impressed that they went out of their way to do finish work on the
porch that we had not even asked for which really added a lot of
polish to the project. All in all it was a great experience and
we would recommend A.M. SunPower to any of our readers. The system has
been working flawlessly since installed and we suspect it will
continue to do so for at least the next 30 years! If not,
we will make sure you are the first (OK maybe second) to know!
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We have been getting a lot of questions
lately as to the costs for a solar
PV system and how soon PV systems pay for themselves. It is not always
easy to tell given the host of federal and state regulations. To
provide some clarity on these cost issues we have updated our section on