Shortly after we bought our house in 1999 in Redwood City, where the city motto is Climate Best By Government Test, we thought about adding solar photovoltaic (PV) panels to our roof. Afterall, this was California where the sun was plentiful and the electricity rates high. Also, it's good for the environment.
We'd read about other people who had done it. (Guerrilla Solar) The cost of a system would be $20K or more, and having just bought the house, we couldn't afford it. Still, we thought we might eventually do it.
Then came 2001, the year of the California Energy Crisis; a crisis quite possibly contrived by the energy companies. So in July, our electricity rates went up again in a tiered rate system, where power used over 300% of the baseline cost $0.245/kWH. Over half our electricity usage was in this top tier. With California offering $4.50/watt rebate on a solar PV system, and PG&E being required to accept hookups (because of the net metering law), solar was sounding even better. Still, a system would take roughly 14 years to pay for itself in reduced power bills, or so I thought.
I met someone who pointed out that with the California rebates and the record low mortgage rates and the mortgage interest tax deduction, you could save more on your electric bill per month than you'd have to pay on the mortgage. By my initial calculations, this wasn't exactly true, though maybe it would have been with the federal deduction you get if you have a home office. But it was true if I added in the monthly savings from refinancing our original home mortgage at the current lower interest rates. I was sold.
The rolling blackouts of 2001 were caused in part by the lousy electrical distribution system in CA. There was energy to be had, but it was difficult to get enough of it to some places that needed it the most. By generating electricity and putting it into the grid during the peak usage hours, we will do our part in reducing rolling blackouts in our area.
We also thought we'd get a natural gas powered backup generator installed at the same time as part of the whole system. The last 17 hour blackout we had, all our friends were asking "what happened to apricot.com?"
We are also planning to add a hot tub inside our gazebo. Not
wanting to drive up our electricity costs a lot with heating
the water, we also wanted to get a solar hot water heater to
mount on the roof of the gazebo.
How to find a Contractor? I searched around the web and found
the California Solar Energy Industries
Association list of member contractors. Considering only the
ones in the SF Bay Area, I went to the California State License Board site and
checked to see that they were licensed, bonded, and had
workers compensation. Next check was the Better Business Bureau site to see if they
were members and what their records were.
Still, how to narrow things down a bit more? One
recommendation was to look for contractors that are licensed
for electrical work, C10 and Solar C46. That, and my
preference for places that have websites, narrowed the list to
three. I called up SolarCraft Services and found they only do
work in Marin and Sonoma counties. Sun Power & Geothermal Energy (now called SPG Solar
) and Akeena Solar
each came to our house to discuss what we were looking for,
and to do a site survey.
Curiously, despite having a C10 electrical license, Sun Power
did not do backup generator installations, though they could
subcontract it out.
The contractors looked at our electricity bills for the past
year and entered our KWH usage by month into their
spreadsheets. They wanted to know our goal. Was it to
eliminate our electric bill entirely, or to get the most
return on the investment? We didn't think we had enough
roof space to do the first, so it was either the second, or
a third option, to cover our roof with as many panels as
would fit. Our house is 1170sq.ft. not including the
garage. Each kW of panels takes up roughly 100sq.ft.
They measured our roof, including the direction and pitch of
each face. The south facing surfaces are the best, and a 30
degree pitch is optimal. Our roof has a 22 degree pitch,
and our house faces slightly south of east. Both companies
seemed to think a system of about 5kW would give the best
return on investment, but that would not all fit on the SSW
facing roofs. Akeena felt the remaining panels should go on
the front facing roof since, by facing slightly south, it
would get more light than the back roof. Sun Power, on the
other hand, thought changing from a PG&E E-8
(old E-8) seasonal
schedule to an E-7
(old E-7) time-of-use schedule would save us the most
money, and recommended putting the remaining panels on the
back facing roof, hidden from the street.
On E7, power used during the peak usage hours of Monday
through Friday, noon through 6 p.m., is charged at the rate
of $.32524/KWH (including the 1/4/2001 energy surcharge) in
the summer, while off-peak is closer to $.095/kWH. The
thought was, with West facing panels, we could run the meter
backwards in summer during the peak hours and get credited
$.325/kwH by PG&E. However, after redoing the calculations,
Sun Power said we'd only save $100/year on the E7 schedule
vs. the E8 schedule. The E7 schedule requires a special
time-of-use meter be installed.
Still, with PG&E asking for more rate hikes, we wanted to
consider a system larger than 5kW. Akeena, which uses 2.5kW
SMA
inverters felt that 7.5kW would be the next logical step
up. They would put the additional panels on the back roof
with reverse-tilt mounts to face more southward and thus get
more power per panel than if the panels were flat against
the roof. I didn't mind having the reverse-tilt panels in
the back where they would not be visible from the
street.
Sun Power, using both 1.8kW and 2.5kW inverters thought the
next step up would be a 6.8kW system, by adding 15 panels to
our front roof. I'm asking them if they can fit 22 panels
and go up to 7.4kW system. Even at 7.5kW, most of the power
we'd be replacing would be at the highest tier surcharge
rate and a little would be at the second highest rate.
Both companies said they would handle the building permits
and the PG&E and city inspections. Installation would
take about a week, inspection would be a week or two after
that, and the $4/watt rebate would arrive a month or two
after that. They would reserve the rebate for us, and
would not start installation until the rebate is approved.
The rebate was $4.50/watt through October 2002 and then
dropped down to $4/watt. It was January, 2003. The rebate
had not yet started up for 2003, but was expected to in
February. The inverters have a 5-year manufacturer's
warranty and the PV panels a 25-year manufacturer's
warranty. In addition the contractors give a 5-year
warranty on the entire system.
Sun Power offered us a 5.2kW system at $51,475, or $28,074
after the $4 per watt California rebate(broken link?) and
the 15% California tax credit. They
estimate this will save us 9,000kWH or $2,100 per year,
reducing our annual electric bill from $5,400 to $3,400.
A 6.8kW system would cost $67,987, or $35,062 after rebate
and tax credit, cutting our annual electric bill roughly
in half by $2,700 or 11,700kWH. At my request, they later
quoted a 7.4kW system. The numbers were $73,265, or
$37,543 after rebate and tax credit with an estimated
13,700kWH or $3,100 savings.
Akeena offered a 5kW system at $52,103, or $27,472 after
rebate and tax credit or a 7.5kW system at $76,911 or $40,278
after rebate and tax credit, a little more expensive than Sun
Power. Curiously, Akeena estimated the savings to be 7,600kWH
or $1,800/yr on the 5kW system and 11,400kWH or $2,600/yr on the
7.5kW system, considerably less than Sun Power estimated for
simlarly sized systems.
The difference seems to be that Akeena used a more
conservative 5.3 solar hours per day, while Sun Power used
closer to 5.5. Also Sun Power seems to have rounded our roof
angle from 22 degrees to the nearest one on the chart in the
more favorable direction.
All savings calculations are specific to our high electric
usage, our usage pattern (pretty flat, no real spikes for
heating in winter or A/C in summer) our E8 billing
schedule, our location (5.3-5.5 typical solar hours per
day), the pitch of our roof and the directions it faces,
shade on the roof caused by trees and buildings. This is
why the site survey is necessary.
To get a feel for whether PV is for you, try out the Clean
Power Estimator
We put on a 30 year fixed rate mortgage, (6%, 0 points,
$3100 estimated closing costs) the cost of the PV system
after rebate. That's roughly $6,000/kW. We put the
rebate amount of $4,000/kW on a home equity line of
credit (.25% above prime, or currently 4.50%) to be paid
off as soon as we received the rebate. This gives us a
$36/kW monthly mortage payment.
By Sun Power's estimates, we'd save $400/kW on our annual
energy bill, or on average $33/kW each month. The mortgage
interest is tax deductible. Over the life of the loan, you
pay an average of $19/kW each month in mortgage interest. At
an incremental tax rate of 27% federal, 9.3% CA state, you
would save $7/kW each month in taxes. That give a total
savings of $33+7-36=$2/kW of installed PV each month.
It's not much, but it's something. I didn't want to go through
the hassle of loan approval and $3100 closing costs for either
refinancing our original home loan, or putting up PV, but
somehow, putting the two together makes it seem worth it. Our
cash flow will improve, but our debt will get larger.
I have not done a Net Present Value (NPV) analysis, mainly
because there are so many assumptions to be made, and a slight
change in one makes a huge difference. However, Akeena did a
NPV analysis with the assumption of financing the system with
a 30 year fixed rate loan at 6.00%, an annual increase in PG&E
rates of 5% (It actually has gone up 5.5% on average over the
past 40 years), a discount rate of 7% (look that one up
yourself. I think it's an assumption that I could have
invested that money elsewhere and made a 7% return), and a
marginal combined federal/state tax rate of 39%. For the
7.5kW system, they came up with a NPV of $28K over a 30 year
life of the system. Also in those 30 years we'd avoid
producing 227 tons of CO2 (carbon dioxide, a greenhouse gas).
I tried to make a more apples-to-apples comparison of the
systems. The results were very close.
In the end we went with Akeena, despite their price being
slightly higher. Perhaps it's a reflection on their
salesmanship. They were quicker at figuring out just what we
were looking for, rather than what people with similar homes
might have wanted. They seemed to take into account more
properly, the fact that our house was not facing due East.
Their layout would more easily allow for expansion, though
that may be unfair, since we hadn't told either company about
our plans for expanding the house in the mythical future.
Being more engineering-oriented, Akeena also was able to
understand Scanner's request to have the raw data from the
inverters go directly by serial port to one of his unix
computers where he could generate reports and graphs to study
the data, particularly in combination with other data we
gather in our house ourselves.
Akeena also made the process easy. When they presented the
proposal, they gave us a binder with details including a
project time line with estimates on how long each phase would
take and exactly how much money we would pay them at each
milestone. They had the Purchase Agreement and other forms
relating to the PG&E and the rebate all ready to sign, and in
duplicate so we could keep one copy to read after giving them
one signed copy. They even included the form for the 15% tax
credit.
We will likely use Sun Power for the solar hot water for the
hot tub. However, since it is not likely to have more than a
5-year warranty, I do not want to put it on a 30 year
mortgage. There are currently no CA state incentives for
solar thermal systems. Sun Power however, wanted to battle for our business
As soon as the CEC started accepting new applications March
3rd, Akeena turned in ours. We got confirmation on March 26
that the rebate had been reserved in our name. Our loans were
approved the first week in March at a rate of 5.75%, which is
lower than the 6.00% I was using for calculations. Our
contract was contingent on the rebate and the loan
approval.
Then we hit a glitch. Akeena came out and took some more
detailed measurements of our roof and took some plans to the
city to start the building permit process. The associate
planner told them they can not put PV panels on the front of
the house or on reverse tilt mounts. Now I've got to find out
the exact ordinances and regulations that apply. I've seen PV
panels on homes in our town visible from the street, but I'm
not absolutely sure any of them are on front facing roofs.
I found a photo on the web of a house with solar panels on the
front roof. The photo was labelled as being of Redwood City.
I took the photo to City Hall. The associate planner was not
in that day, so I spoke with the zoning administrator who said
that you can put panels on the front roof, but they must
conform to the pitch of the roof. She also wanted them to
look more tidy with fewer gaps between them. She didn't want
any reverse-tilt mounts visible from the street.
Akeena came back to our house to take more measurements on
March 25. We decided to try using the new Sharp 185W panels instead of the Sharp 165W panels of the same size. That
way we could use fewer panels to get the same power, to avoid
having panels hanging off the top corners of the roof.
We also changed the reverse-tilt mount panels on the back roof
to flat mount so we could fit in more panels there, despite
losing about 14% collected energy because of the less
favorable orientation. It seemed a good tradeoff. That still
left 8 panels on the NNE facing roof since we couldn't fit
them all some place else. Changing those from reverse-tilt to
flat mount costs a 33% loss in collected energy per panel. I
am not happy about that and would like to see if we could move
some of those panels to a more favorable orientation.
Remeasurement of the location of the vents on our
front roof proved that we had more space than expected on the
front, and that we could arrange the panels without gaps
between them.
I re-did the comparison of the systems. The redesign
gives us 8% energy less than the original Akeena proposal, and
also less energy than the SunPower proposal.
A few days later Akeena sent me a new roof PV
layout. The PV array operates more efficiently if all the
panels on each string are facing the same direction. So they
put 2 strings of 8 facing front, 1 string facing back, 2
facing SSW and 1 NNE. This layout would give us 7% less
energy than the original Akeena proposal.
I still wasn't happy with one string being on the NNE side, so
I sent them a proposal to move the string to the back. They
sent me another layout just slightly different
from my proposal. This one while giving us 5% less energy
than the original Akeena proposal, gives us virtually the same
annual $savings. This is because more of the power is
generated in the summer when the electricity rates are
higher.
Akeena submitted the building permit application on April 2.
The planning department didn't like the look of all the panels
on the front, but would accept an orderly 2 x 4 rectangular
array of panels in the front. Akeena got them to accept
moving the second string of 8 from the front to the NNE side
of the house, flush mounted. Akeena sent me the final
design on April 9. Since 8 of the panels are once again
on the NNE roof, we are back at losing 8% of the energy bill
savings compared with the original Akeena proposal.
The panels and other materials were ordered to arrive on
April 25, but rain delays on other customer's projects have
pushed the start of installation to May 8, 2pm.
The first day they brought the mounting rails and started
taking measurements on the roof to determine exactly where to
attach the rails to the roof rafters. A few brackets were up
on the roof by the time they left. They also brought some
paperwork for us to read and sign for the $4/watt rebate.
Then there was the invoice for the building permit $340.75,
which I figure they paid to Redwood City, and the Design Fee
$2730. The second day they put up some rails on the
front and side of the house. They didn't come Monday or
Tuesday because of some emergency at their office. Wednesday, late morning they came back. They brought the
inverters and 16 of the panels on the first trip in their van.
Despite the photo in Sharp's brochure, the silicon chips on
the panels look black, not dark dark blue. So I was planning
to pay the $55,964 charge for the equipment today, but the
installation guys disappeared around 3:30pm without a word.
During the day, they brought up 8 of the panels to the roof and
installed 3 of them on the garage. They put up a large piece
of plywood on the side of our house and mounted the 3
inverters, the DC cut off switch and the AC cut off switch on
it.
Thursday, they came earlier than usual, around 9:30, or maybe
earlier. Not seeing the Akeena van, I didn't know anyone was
here until we saw the ladder was set up again. Scanner talked
with John, who was working on the electrical stuff and they
agreed the plywood would be painted gray to match the vinyl
siding. Later while admiring the 4 panels installed on the
front roof, John asked me if I got the feel for how it would
look. I commented that I wasn't sure RWC would like the way
the corner of one of the panels on the garage appeared to stick out. John called up to
Julio on the roof to tell him he had the "fun new job" of
moving the rails over by a foot. As you can see, there is space to move the rails. I
gave them the check for the equipment as well as the second
copies of some forms that I had thought were our copies, but
apparently PG&E needs both copies. At the end of the day
there were 15 or 16 panels installed. I don't see how they
can finish the job in the 5 days they originally estimated,
but I figure that's because they were estimating based on a
typical project with fewer panels and/or lower percentage of
roof space covered.
Friday they appeared at 9am. With the 8 panels on the front
roof, passersby were stopping to ask about them. "How many
panels?", "Will they use batteries?", "How much does it
cost?", "Wow, that meter is spinning fast, will it really spin
backwards?" Yes, it will, every sunny day of the year.
The panels on the garage roof were moved so they would not be
visible from the front of the house. 8 panels more panels
were put up on the South facing roof, which is nice, since the
plan showed only 7 at that location, while a String is 8. Nice
to have them all lined up in one spot. A conduit was
installed through the roof to the switchbox, and a bunch of
wiring was done. 20 panels on the roof at the end of the day.
John had to leave early at 3pm to get ready for a trade show.
Julio left at 4pm.
Saturday Julio and another installer spent a couple of hours
of overtime and put up 3 more panels.
Monday they came at 1pm, since their weekly Monday morning
meeting ran late. They took measurements of the back roof
where 15 panels will be fit "like a puzzle", and marked off in
red where the rails and mounting hardware would go. Some more
wiring went on at the side of the house.
Tuesday they showed up bright and early around 7:30am and
brought the remaining 16 panels with them. They put the
brackets in the back roof, and then the rails, and then the
clamps. Suzanne, the office manager showed up to see how an
installation goes. It was hot out, as was Monday. Barry, the
President of Akeena dropped by to see how things were going,
but it seems I missed him again. Then around 2pm, Gabe showed
up to help with the installation. The newly delivered panels
went up on the roof. Seven were installed on the bottom row
where the drawing only shows 6. The 7th one is
visible from the street. In total, 30 of the 48 panels are
installed.
Wednesday, two started working at 8:30am. Looks like they did
some wiring of the panels and then started questioning how to
get 2 strings of 8 panels in the south facing direction,
considering they had fit 8 panels instead of 7 on the bottom
row and they had not reverse tilted the panels on the small
north-facing roof. It would be great if they could fit 4
panels on the top row instead of 3. They put in some brackets
on the final north roof and left at 3pm saying it was too hot.
Thursday they arrived before 8am again and put up rails and 4
of the 8 panels on the north roof. They managed to fit the 4
panels on the top row of the south roof, so they removed the
no-longer needed rails and panels from the small north-facing
roof. They also removed the panel and rails from the small
west roof, which I take to mean they feel they can fit all 16
panels on the large west-facing back roof. The shifted the 7
panels on the lowest row of that back roof over to so the last
panel would show as little as possible from the street. A lot
of ground wiring went up, and the Sunnyboy Control unit was
installed.
Friday they put up 7 panels on the middle row and 2 panels on
the top row on the back roof for a total of 16 on that roof.
The top panels are just barely visible from the street. The
last of the 7 panels on the middle row is more visible from
the street. After putting up the 8 panels on the north roof,
they trimmed off all the excess rail. With all the panels
installed, only wiring should be left.
Memorial Day, they actually came and worked almost the entire
day on wiring. Tuesday they were back again for another hot
day that hit 90F by the time they left at 2:45pm. They said
they will be back for two more days to redo some of the wiring
to make it safer and add some more junction boxes. I must say
I'm a bit puzzled, considering all last week even on Friday,
they kept saying they thought they'd finish that week.
Suddenly there's four extra days. Still, if it's for safety
I'd rather have it done right even though it takes longer
Wednesday they finished up on another 93F day. They called
the city to request an inspection on Friday, although since
they called before 3pm, they actually could get the inspection
on Thursday.
Apparently the city inspector came unannounced on Thursday,
which we didn't find out until John from Akeena showed up on
Friday and called the city to find out what was going on. The
inspector marked off a couple items on the permit, including
some labelling which Akeena had planned to do on Friday while
waiting for the inspector to show up. Friday, May 30, John
did a brief commissioning test run. Despite it being an
overcast morning, I could see our electric meter noticeably
slow down. He also showed us where the fuses were in the
unlikely case they ever blew.
Monday, promptly at 9am, the Redwood City inspector arrived.
Seeing no changes, he was about to write up the same items as
on Thursday. Fortunately John from Akeena arrived a few
minutes later with the labels and a 50A breaker while the
inspector was still there and got a signoff on the permit. He
also sealed the joint on the EMT conduit on the AC side and
tightened some joints. There was also talk of a lightning
arrestor. Many locales require this, but Redwood City does
not. We rarely have lightning storms.
In all the excitement I forgot to give John the check for
completion of the installation and the permit signoff. I can
mail it in.
I called Akeena later in the week to find out when PG&E would
come for an inspection. Apparently there was a bit of
miscommunication and PG&E hadn't been notified yet, because
the right person hadn't received the building permit signoff
yet. But that got straightened out and we waited for the call
from PG&E. Meanwhile the usually monthly meter reading on the
18th came and went.
Finally we got the call and the PG&E guy came out on June 20.
He asked us to turn off our lights and computers and other
power-using appliances. Then he had us turn on our solar
system. It takes about 8 minutes for the inverters to come up
and start feeding power into the house. We watched as the
meter started turning backwards. He then threw the main house
breaker off to verify that when there is no power from the
grid, the inverters also shut off power from the PV array.
This is to ensure that during power outages, the PV array does
not feed power into the grid endangering utility workers. It
worked just fine.
Then he had us turn the solar system off. He was surprised at
the meter was still spinning forward at a decent speed. We
figured it was because off all those devices that always on,
even when they are off, such as all the A/V equipment, the
UPSs, things with clocks in them, such as the microwave, and
the "wall-wart" chargers.
We both read the old meter before he swapped out our old meter
for a new meter which was guaranteed to measure power usage
accurately in both directions, running foward and backwards.
I take this to mean that while our old meter ran backwards and
seemed accurate enough to me, it was not guaranteed to be
accurate when running backwards. He had us turn our solar
system back on and he put a tag on our new electric meter
stating that our house is approved to interconnect our power
generating system to the grid. It's official! Just in time
for the first day of summer, the longest day of the year.
The first month, we generated 1376kWH, averaging almost 46kWH
per day. Not quite as high as predicted, but quite nice. We
reached as high as generating 49kWH on our best day.
We received an electric power bill for the two days between
the last regular meter reading and when the new meter was
installed. Curiously, our power consumption has gone down,
not even considering the solar. This is likely due to
decommissioning two of our oldest power-hungriest computers,
and the failure and disconnection of one of our old UPS
(uninterruptible power supplies)
After a full month we got our first bill under the net
metering. Instead of the usual small envelope, it was a
10"x13" envelope with the usual small bill enclosed, and seven
8.5"x11" sheets of details relating to the net metering bill.
Basically it charged us for the $.45733/day rate we have for
just being connected on the E-8 schedule plus the related
legislated reductions, surcharges and taxes. This came out to
$12.11 for 28 days for us. We actually generated 73 KWH of
energy more than we used. This was listed as a "Current
Unbilled Credit is: $-8.63". It's a nice thing to see.
It's ironic, since we used less power than we historically have, we
only saved $231 on our bill vs $317 if we had continued to use
80KWH/day. This means that our payback period on the solar
panels will be even longer. But I'm not looking a gift horse
in the mouth. A smaller electric bill is a smaller electric bill.
For the month of July, we generated 1325 kWH of energy which
is 9% less than the 1459 I predicted. Some of this might be
because the trees in our back yard have grown taller and do
cast a shadow on our west-facing panels in the late afternoon.
Some of it might just be natural variations. It should help
if we rinse off the panels which have gotten dusty.
Since we do not have a time-of-use meter, I don't think we can
ask PG&E for a rate comparison of E-8 vs E-7 for us after 12
months. However, Scanner did install a device that will send our
house power usage information to his computer. Combined with
the data from the Sunnyboy Controller, we should be able to do
the rate-schedule comparison ourselves.
On August 8 we received the $4/watt rebate check. Not bad.
That's less than the 2 months we were warned it might take for
PG&E to cut the check. It's nice to get a $29,472 check. Now we
can pay off the home equity line of credit.
I noticed the check was smaller than I expected. Somewhere
between February, when I first calculated the rebate, and June
when Akeena submitted the paperwork for the rebate, the CEC
changed their inverter efficiency ratings from 3 significant
digits to 2. So the CEC listed efficiency for the Sunnyboy
inverter went from 94.4% to 94%. That missing 0.4% has cost
us $126 worth of rebate. That just adds a few more weeks to
our payback period.
UPDATE 2005 - I no longer think we actually used less energy after
putting in the solar arrays. For one thing, another UPS died in 2005
and I did not see a significant drop in our power usage. I also got
a Kill-a-Watt meter in 2005 and found that the percentage difference
between VA and RMS Watts is about the same as the percentage difference
in our KWH/day before PV vs after PV. A friend who has some knowledge
of electric meters told me that a lot of the old dial-type meters
measure VA, while the new digital meters measure RMS Watts. Suddenly I get
the feeling that we've been over-paying for electricity for years.
During our first year on the net-metered billing, our solar
panels generated 10,536KWH of energy. That's 7.5% less than
Akeena originally estimated. This is not surprising since
they weren't assuming that any of the panels would be facing
north. The idea was that they could be reverse-tilted.
However Redwood City didn't like the reverse-tilt idea. The
10,536KWH generated was also 6.5% less than the 11,270KWH I
estimated using the nrel PVWATTS calculator. We still haven't tried
calculating how much of this is caused by the shade from our
neighbor's tree in the late afternoon.
We saved $2,010 in that first year, compared with what our
electric bill would have been if we had no solar panels. This
is 23% less than Akeena predicted, but besides the 7.5% lost
because of the north-facing panels, the prediction is off
because it was based on our using close to 80KWH/day which
would put is in the top billing tier with its 12.505 cents/KWH
surcharge. If all the energy the PV panels generated had gone
to offset top-tier power usage, we would have saved $2,390. We
actually averaged 45KWH/day in energy consumption.
Our electric bills from 5/21/2002 to 5/19/2003 totalled
$5,517. Our bills from 6/18/2003 to 6/17/2004 totalled $817,
$668 of that was for the net energy used, $149 was for just
being connected to the grid. So compared with the previous
year we saved $4,700. As previously mentioned $2010 of that
was savings from the PV production which means $2690 was from
conservation, or using less electricity. Update 2005 -
or from the old dial meter overcharging us based on VA instead
of Watts.
If we had been on an E-7 billing schedule, we could have saved
roughly another $500 which would have brought our annual
electric bill to a total a little over $300. However, I knew
we were getting a jacuzzi (it was installed on June 3), which
increases our power consumption and I want to make sure that
the E-7 schedule will still make sense before I change to it.
Once we change to E-7 we can't change back to E-8.
Now that I've done the analysis, I realize I didn't have to wait.
I could have figured it out 6 months ago when I had a full
half year's data from the longest day to the shortest day of
the year. It is highly unlikely that we'd ever use enough
additional power to wipe out the $500/year E-7 vs E-8 savings.
If we increased our power usage by 35KWH/day, from our current
45KWH/day to our previoius 80KWH/day, and if that power were
spread out evenly throughout the day (as uninterruptible power
supplies (UPSs) and computers always on might be) then we'd
lose about $168 of that $500 savings. We'd still save $332/yr
with the E-7 schedule. To wipe out the $500 savings we'd have
to either use 104 more KWH/day than we do now (spread evenly
throughout the day) or use 11 more KWH/day during peak hours
(that's like having 2670 more watts on continuously during
peak hours).
Towards the end of July 2004, I called up PG&E customer
service and asked to switch to the E-7 Time-of-Use schedule. The lady on
the phone offered to send me a rate comparison to see if
changing billing rate schedules would save us money. I was
surprised. I didn't think they'd have the data to be able to
send me such a comparison, but I said, "Sure!". While trying
to send that out to me, she realized she couldn't, and that I
had to call the Business Customer Center, whose number is on
the multipage 8.5"x11" bills I get once a month right after
the smaller residential bill arrives.
So I called up the Business Customer Center and they said I
needed to fill out a new form and send a check for $277, and
no they couldn't send me a rate comparison. The form arrived
in the mail the very next day! I sent in the form, which came
back the next week with their signatures on it.
I wondered what was next? Would they call to schedule a day
to switch the meter? No, they just showed up one morning,
10:40am, Tuesday, August 3rd. I suppose they would have
knocked on the door first before switching the meter, but
Scanner happened to be walking out the door just that minute. We
shut down as much as we could in the house (other than phantom
loads and such), turned off the solar system, and they swapped
out the meter. It was nice to see after just 4 hours that we
had already sold 14 KWH of power to PG&E. (50000 on the meter
is what we'd normally think of as 0.)
A couple of days later the bill detailing the $277 showed up.
$152.96 was for the meter, CIAC tax on that was $52.01, which
comes out to 34%. Wow! "CIAC" seems to stand for
"Contribution in Aid to Construction" and is some kind of
Federal tax. The remaining $72.03 was for installation costs.
Since I expect that the E-7 schedule will save us about
$500/year more than the E-8, the $277 should pay for itself in
about 7 months.
Another thing we've noticed, is that spraying the solar panels
with water is not enough to clean them after months of no
rain. We've been using a squeegee to help clean the panels we
can reach from a ladder.
The first E-7 TOU bill showed up. I noticed that the
surcharge rates dropped for usage above 130% of baseline.
This is one of those gifthorses not to look in the mouth. The
good news is slightly lower bills, the bad news is that it
makes the financials of the PV look less attractive. Adding
the effects of the lower surcharge rate and us going to the
E-7 schedule, I think we come out ahead. (The lower surcharge
rates has something to do with the politics involved with PG&E
getting approval to get out of bankruptcy. Someone demanded
that the ratepayers get something out of the deal.)
We had the meter swapped out half way between two regularly
scheduled meter readings. For the last two weeks on the E-8
schedule we had a "current unbilled charge" of $30.97. For
the first two weeks on the E-7 schedule we had a "current
unbilled credit" of $20.15. We saved $43.50 with the E-7 vs
the E-8 in those two weeks alone. It's always nice to see a
credit.
Surcharges started going up again in June 2005 and then
October. In January 2006 it rose above the June 2001
surcharge rates and in March they went even higher. Now on
the E-7 TOU schedule, in the summer during peak hours, the
highest tier rate is 50.5 cents/KWH.
I have mixed
feelings about this. On one hand our electric bill is going
up, and on the other hand, that means the solar panels are
paying for themselves faster. While this was expected, I had chosen not to depend on it for my payback calculations.
Hidden among all these
changes in surcharges, they added in a change in
calculation method that I don't have mixed feelings about.
They are definitely adding to my bill and reducing my savings
by artificially lowering my baseline quantities and thus
increasing my surcharges. Details at When Net Metering is Not Truly Net
Metering.
I sent a formal complaint letter to PG&E with my calculations
of just how much I believe they overcharged me and how much they
decreased my Total Baseline Quantity. If they say that the CPUC approved
the changes, I want it in writing. I haven't found anyone else who says
the same thing has happened to them, but I suspect that it's not because I'm
the only one. I think it's because the 16 page bills are difficult to verify.
I take http://debris.com/journal/1453 as evidence that it's happened to this solar blogger. A $400+ error was caused by one meter misreading followed by a correct reading. There wouldn't be such a huge error if it were truly net metering.
PG&E sent me a letter acknowledging that they received my complaint.
A month later, I still hadn't heard from the CPUC.
As of May, customers can no longer switch to the E-7 schedule, but
those of us already on it, can stay on it. Instead they have reopened
the E-8 Seasonal schedule and opened an E-6 Time-of-Use schedule that
has peak hours, partial peak hours and off-peak hours. I did some
calculations and found that the E-6 schedule would cost us more than the E-7
schedule.
Two months after I sent in the letter complaining about the changes in billing
calculations, I got a phone call from the PG&E executive office. They
apologized for the delay. I was pleased to hear that I was not the
only customer to complain and that PG&E's tariff department agreed
with me that the billing is incorrect. Since they are a regulated utility,
they have to file a petition with the CPUC to change the billing calculations
and the CPUC has to approve it. Then PG&E will go through the billing
records back to October 2005, look at all the customers and credit the
accounts accordingly. This should happen by the end of the year.
Meanwhile, I was promised a letter in writing explaining
what happened. The verbal explanation didn't make much sense to me.
Yes, I understand that the new calculation method works fine for most
people, and is only a problem for those of us who generate power and
send that power back into the grid from time to time, but that does
not explain why a perfectly good calculation method before October 2005
was changed at all.
For our July 19 to August 16 bill, I noticed that the baseline calculations have reverted back to the old correct way. This is different from the change that PG&E said they'd do in the letter they sent me.
I wonder instead if this is the result of more games with baselines
and surcharges. On August 15, PG&E issued a news release stating
Our bill for the month covering the heat wave was $71 for the
electricity. If they had calculated it the same way that they had for
the previous few months, it would have been $101. By charging us
correctly that month, they get to send us a smaller refund check in
October. If they go back to the incorrect way of billing the next
month, it will be very hard to convince me that they aren't playing
games with baselines for their financial benefit.
Well, they didn't go back to the incorrect way of billing, and we
got our October refund check, but we have not ever gotten a credit
for all the months that they over billed us.
In February 2007, suddenly the usual 17 page bill became a 2 page
bill with extremely few details. At least their dollar amount for
the month matched mine. But are they preparing for more funny business
with billing and making it so there's no way for us to see what their
mischievous calculations are? Despite the bills with no calculation details, there has not
been any more funny business these past few years. My calculation
for the bill come to within a few cents of their bill.
The differences can be attributed to rounding errors.
In 2009 electricity rates went up again. The highest tier rate on
the E-7 schedule went to 61 cents per KWH during summer peak hours.
In the sixth year, 2008-2009, we saved on our electric bill 42 cents
per KWH generated by the PV array. In the seventh year, we saved 47
cents per KWH generated.
Federal and all States
Incentives for Renewable Energy
California Incentives for Renewable
Energy
Calculators
Solar Contractors in the US CalSEIA solar contractors in the San
Francisco Bay Area:
Glossaries
Non-traditional technologies
Custom Production
Future technologies
Other interesting pages
last changed 2009.12.21Looking for Contractors
Site Survey
Proposals-Cost & Savings
Financing
Decision
Bureaucracy
Redesign
Installation
Official Production
The First Month
The First Year
The Second Year (TOU)
The Third and Fourth Years (Games with Baselines and Surcharges)
Per our conversation today, PG&E is in the process of filling (sic)
with the CPUC to "requests authority to revise Special Condition 2
entitled 'Net Energy Metering and Billing' to address baseline
allocation where a net energy metering (NEM) customer's net usage for
all time-of-use periods totals zero (i.e. when net generation in one
or more periouds exactly offsets the net usage in all other periods),
then the value of usage and/or generation will be calculated using
Tier 1 rates (as set forth in the otherwise applicable rate
schedule.)
Considering that there were positive and negative usage values in my
bill for Tiers 2, 3 and 4, this does not appear to be the result of
the new filing.
The utility plans to provide a one time bill credit of 15% for all
residential customers... The prolonged regional heat wave in late July
caused a spike in electricity consumption as customers were struggling
to stay comfortable in the blazing temperatures. Comparing July to
June, PG&E residential customers' electricity usage increased by an
average of 28% per customer from 537 kwh to 690 kwh as a result of the
high temperatures and average bills increased an average of 44%, from
about $79 to $114....The proposal enables PG&E to accelerate the
credit that customers would normally receive at a later date. PG&E
anticipates that the total amount credited to customers in October
will be approximately $125 million.
The Fifth, Sixth and Seventh Years
Links
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Power & Geothermal Energy, now SPG Solar
