Going Solar: A Chronology of Events
OR: How to look forward to getting your electric bill each month!

Download MS Excel data file here
(data file last updated 11/07; 124K)

|Below in the chronology some of this is explained, but this
graph shows quite a bit. The maximum is what you can assume the
average would have been if the day length remained the same
and it was never cloudy. The difference between the max and average
 shows the effect of clouds or shortening days. The decreasing max
between June and December is mostly due to day length and angle of
 the sun.

February 2001
I began seriously researching/pursuing the idea of installing a photovoltaic grid-intertie net-metering system for my house. I contacted Jim Harper of Sierra Solar for an estimate and obtained some background materials from Jim.

March 2, 2001
Quote from Jim for installation of a 1.5 KW system. Parts, labor, and sales tax would be $13,867 minus the $4,689 CA state buydown. Estimated production 8 kwh per day.

March 4, 2001
Quote from Jim for installation of a 1.2 KW system. $10,890 minus the $3,516 CA state buydown. Estimated production 6 kwh per day. This was more in my price range.

March 5, 2001
I faxed in the Reservation Request Form for the Emerging Renewables Buydown Program (that Jim provided) to the California Energy Commission for the 1.2 KW system. I attached a recent electricity bill and Sierra Solar proposal signed by me.

March 20, 2001
We received confirmation that my buydown reservation for $3,441 for a 1.147 KW system was granted. Jim ordered the necessary materials.

March 30, 2001
Jim obtained a building permit from Mono County.

April 17, 2001
I faxed the "application for the interconnection of a small solar or wind powered electrical generating facility" (that Jim provided) to Laura Rudison at SCE, who worked for the director of QF resources.

April 23, 2001
I wrote Jim a check for 1/2 the amount (after buydown), $3,784.50 deposit. Jim began work.

April 26, 2001
We received from SCE the confirmation that they received the application with an attached agreement.

April 27, 2001
I signed and faxed to SCE the completed "Net metering and interconnection agreement". Date system expected to be ready to operate: May 1st.

May 1, 2001
Jim was finished with the work and the system was ready to operate. Mono County Building Inspector inspected the system (The first one in Mono County!). I wrote a check for the other half, adding up to a grand total (after buydown) of $7,565.10. This amount included a building permit ($117) and California Sales Tax ($628.60). Includes 5 year warranty on all parts and labor (on top of a 25 year warranty that comes with the solar panels themselves).

May 7, 2001
Notice of Final Building Inspection from the County. I faxed this to SCE. This was all they needed to give the okay to turn it on--but I was required to wait for their official okay. We also faxed the buydown claim form, final building sign off, final purchase invoice, recent utility statement, and 5 year warranty to the California Energy Commission so Jim could get paid (the state pays the buydown directly to the contractor).

During the following two week period, I periodically called Laura Rudison at SCE to see when I would be able to turn the system on. She said her boss needed to sign the agreement, but he was on the Governor's task force and busy with more important matters. It was very frustrating to have a completely operational system that I just paid thousands of dollars for that I wasn't allowed to turn on.

May 21, 2001
I wrote a letter to the L.A. Times regarding SCE's two-week delay in giving me the okay to turn on my system during this power "emergency". I notified SCE that I wrote a letter to the L.A. Times. This letter was never printed, as far as I know. I also submitted a tongue-in-cheek question to Dr. Science's Website asking why my electrons weren't as good as SCE's, hoping to generate additional publicity over what I considered to be ridiculous behavior on the part of SCE. As far as I know this question never was answered.

May 22, 2001
5:00 pm, Laura Rudison called to tell me it was okay to connect my system to the grid. I turned on the system! I notified the L.A. Times that I received permission and they should edit my letter accordingly. I later received the agreement signed May 22nd, letter dated May 23rd. I was very happy. :-)

End of May, 2001
My May electric bill was for 152 kwh, double what it should have been if there had been no delays. This bill marked the beginning of the Net Metering agreement with SCE for billing purposes. At the end of May, 2002, I must pay for my net electricity use (if any) for the year.

May 22-June 21, 2001
Average Daily Production: 5893 wh (818w average maximum daily instantaneous)
Maximum Observed: 7907 wh (1265w instantaneous)
During this time, I received a check from Jim for $1,720.50. It turns out that Assembly Bill 29x increased the buydown from $3.50 per watt to $4.50 per watt (50% of the total system cost). This, combined with Bush's $300 tax rebate and an unexpected check from my mortgage escrow account, allowed me to pay off the low interest credit card on which I had put part of the cost of the solar. In the fall I received a letter from the California Energy Commission asking me to confirm that I did receive this additional amount.

Graphs are interpolated between readings.

June 22-July 21, 2001
Average Daily Production: 5207 wh (653w average maximum daily instantaneous)
Maximum Observed: 7135 wh (1325w instantaneous)

July 22-August 21, 2001
Average Daily Production: 4700 wh (300w average maximum daily instantaneous)
Maximum Observed: 6685 wh (1147w instantaneous)
There was a problem with the inverter. It was shutting down occasionally when it was in full sunlight. After some troubleshooting and after Jim spoke to Trace, it was determined that it was pulling power out of the panels too aggressively and shutting down. It was also possible that it was a temperature problem. Jim replaced the "aggressive" chip in the inverter with a less aggressive one on August 24, 2001. It fixed the problem and power output was much much more consistent after that.

August 22-September 21, 2001
Average Daily Production: 4955 wh (816w average maximum daily instantaneous)
Maximum Observed: 5270 wh (1173w instantaneous)
First (almost) full month with the new chip--note higher average (and instantaneous) values than previous month. This could be due to less clouds due to less thunderstorms.

September 22-October 21, 2001
Average Daily Production: 5118 wh (685w average maximum daily instantaneous)
Maximum Observed: 6086 wh (1101w instantaneous)
Note the greater production in the afternoon. This could be because SCE trimmed the trees under the power lines west of the house, or due to less afternoon thunderstorms shading the panels. Also, the angle of the roof (and the panels) is more directly pointed at the sun in the spring and fall than it is in the summer.

October 22-November 21, 2001
Average Daily Production: 4924 wh (763w average maximum daily instantaneous)
Maximum Observed: 5803 wh (1088w instantaneous)
The following graphs show PST instead of PDT. One annoying thing is that since I chose annual billing, my monthly bill always includes a letter saying that I don't need to pay at this time. You'd think they wouldn't need to waste an extra piece of paper every month to tell me the same thing--signed in blue ink, of course, so some guy is sitting at a desk signing all these unnecessary letters every month that say the exact same identical thing. I read it last month already. And the month before... I also have chosen the option to have my monthly bill directly debited from my account, which could create an interesting situation if I ever have a negative bill. So far I've only had a 0 kwh bill (October 2001), which costs $1.46 for connection fees.

November 22-December 21, 2001
Average Daily Production: 2203 wh (449w average maximum daily instantaneous)
Maximum Observed: 4303 wh (1012w instantaneous)
19 days of clouds or snow really depressed the average this month.
Somewhere around this time the fan in the inverter started getting noisy after it came on in the mornings. It seemed like at least half of the sunny mornings between 8 and 9 am it would do this. I called Jim and told him about it (and let him listen over the phone). He ordered a new fan from Trace and was planning to replace the old fan soon.

2002
The new fan still made noise in the morning, so Jim took my inverter and sent it back to Trace in March. Two months later they sent a newer model. It was awesome! 30-40% more power production and so quiet you can't hear it standing next to it!!! He also threw in a readout that I installed on a wall inside the house that keeps the daily production in memory. I haven't been as good about keeping track this year as I was last year, so the monthly graphs above won't be continuing, but in October I really tried to keep track as much as possible, so I can compare October 2002 with October 2001. I'll post the numbers and graphs here at some point. The 30-40% increase in production over last year might also be due to some pruning I did in March. I halved the height of the poplars that are just southeast of the house and shaded the panels in the morning (and used the wood to build a cool fence around my yard!).

2003
I'm getting some awesome production figures out of the system. May 2002 - May 2003 I had a net use of about 1100 kwh. I used to use three times as much electricity! I'm saving about $200-300 per year. Also, in May I switched to Time of Use (TOU) billing. SCE charges a higher rate from 10-6 on weekdays and a lower rate the rest of the time. Supposedly the system should pay for itself twice as fast, since the electricity I produce (during the day) is worth more than the electricity I use (at night). From May-November my bill was negative every month!

In the graph below you can see how TOU had an effect on costs before/after the billing switch--approximately a 2/3 reduction in cost, from $150/year to $50/year.

January 2004
I noticed since October a decrease in electricity generation of roughly 1/3. I called Jim Harper of Sierra Solar and asked him what could be the cause. He checked it out and found that I had blown a fuse, and was only running 8 of my 12 panels. He said it could have been lightning that blew the fuse. I imagine in future inverters there should be some light or alarm that comes on that tells you when you blow a fuse--otherwise if you didn't pay attention and keep notes like I do you'd never know!

May 2004
My electric bill for the year was $64.09. $32 was for electricity and the rest was other charges, including an exorbitant $24 TOU meter charge that I wasn't expecting. While still a pretty good deal, the non-electricity charges are a disincentive for people to switch to TOU net metering. I shouldn't complain, but since my goal is no net use of electricity and no bills, these fees make this goal impossible to achieve unless I disconnect from the grid and begin using batteries (I'd just spend the money on batteries instead). When the grid becomes unreliable as fossil fuels run out, I intend to do this. Unfortunately this would deprive the grid of the benefits of my system helping to satisfy peak demand and use excess electricity at night. The solution? Solar required by law to satisfy the electricity demands of all new construction.

March 2005
Average monthly net electricity use has declined from about 350 kwh prior to installation of the system (and conservation investments) to around 100 kwh. This is an average monthly savings of 250 kwh. The graph below shows monthly net use in purple and annual average monthly net use as blue dots. The peak net use each year occurs in December. Record snow and fog limited generation in January 2005 to only 17 kwh. Snow removal from the panels is not always easy. Seems like including a heating element that could be turned on to melt the snow would be cost effective for 2-story buildings.

April 2006
My Trace Suntie inverter broke. It just stopped producing power one day. I'm told my inverter has an 80-90% failure rate, and since they were only warranteed for 2 years and the contractor has to warranty them for 5 years, he's lost thousands of dollars on them. He's replaced 4 of the 5 he installed. It was an early model with lots of problems. I am getting it replaced with a newer model that has great customer satisfaction and possibly a 20% increase in power output. Ah, the risks of being an early adopter...

Jim installed the new inverter: a Xantrex GT2.5NA. It has a heat sink instead of a fan (quiet!), a higher voltage than the old one (190 volts vs. the old 70 volts), is shorter (I'm going to have to do a little painting and caulking around my vinyl siding), and doesn't have a jack for the remote monitor I have mounted on the inside wall. From reading the owners manual, it appears you can plug in a serial cable that will connect to a computer. I may attempt to do this at some point.

October-November 2006
Since I don't have the readout inside my house anymore, and I can only check the outside daily production while it is still bright out, I haven't been able to keep track of daily values as much. I noticed the following pattern, however (I tend to check more on sunny days--big numbers are exciting!):

There appeared to be a significant reduction in energy production on 10/15, even though weather conditions were similar to the previous day. Just before Thanksgiving I called Jim Harper, and he came out the day after Thanksgiving to investigate. Everything appeared normal. What is probably happening is that the old inverter separated the 12 panels in 3 arrays of 4 panels, and if one array was shaded the other two would continue producing power. The new inverter lumps all 12 panels into one array, and if some of the panels are shaded, it decreases the output of the entire array.

With the sun going down at about 2:30 pm in late November, this shading effect could be significant. "Dirty electricity" could account for the big drop from 10/14 to 10/15--if the grid voltage isn't within a specific range, the system shuts down.

While the shading effect appears to have a significant effect on winter electricity production, the new inverter's dramatic increase in summer production will hopefully balance the net effect. November's generation was the second lowest ever despite sunny weather.

More data and graphs:
Download MS Excel data file here
(data file last updated 11/07; 124K)

HOME
Copyright © 1998-2008 Gregory J. Reis