The more Annette and I read, heard, and saw about what some are calling "climate change", others "climate catastrophe", the more we were getting concerned. No matter, what the right word might be to accurately describe the present climate situation, we believe we can only slow down (or bring to a halt) the numerous factors that will eventually turn the "change" into a "catastrophe", if several things happen: As much fossile energy as possible must be saved, renewable energy must become affordable for everyone, both governments and individuals must take a decisive stand, and much more. That way "going green" will eventually gain sufficient traction or - to use a contemporary word - will become cool!
Well, while hiking up to the peak of Mount Sustainability (ask us about that expression!), it is probably as cool as it gets to have photo-voltaic [PV] panels on our roof knowing that those are producing most of the electricity we are consuming. If there is a surplus, it is being fed back into the local electricity grid to "help some neighbors out". Annette and I did some calculating and decided to take the plunge.
Quick status of the 487N9th "solar plant" (in this frane) or in a new frame, in case you want to explore indenpendently (hosted by SMA Germany, the company which built our converter and is offerring the hosting for free when purchasing their "webbox")
California Solar Initiative: PG&E's description of the CSI, a ten-year, $2.1 billion solar incentive program for existing residential homes and others in California.
California ISO status: This is a page that shows the current load of the California high-voltage wholesale power grid. More about the California ISO (CA Independent System Operator) here.
CSI EPBB (Expected performance-based buydown calculator): Handy tool to estimate the amount of money that you might expect the State of California to contribute to your installation. In our case, the filled form looked like this, the returned results added up to this.
Commercial
Renewable Power Solutions: Our contractor. Very knowledgeable and friendly folks that have answers for all our questions.
SMA USA: The manufacturing company of the inverter that we will be using.
Sunny Portal: SMA also provides a portal, where the data of a solar installation can be collected, presented, and administered. Free of charge, in this case.
Fat Spaniel: A San Jose-based company that provides monitoring services for residential solar installation. For some, this might be an alternative to the Sunny Portal (look at an example for their monitoring visualization). However, we like the flexibility of the approach provided for free by SMA/Sunny Portal.
Solar modules: SHARP ND167U1 (STC: 167 W, PTC: 147.1 W).
Monitoring/communications: SMA Sunny WebBox: Integrated webserver, providing options to send data to a monitoring facility or notification emails. Has a long, but good manual.
Monitoring portal: SMA maintains Sunny Portal, a monitoring server facility (their manual), which allows for data access of your installation around the clock from any connected computer world-wide. We are planning to use this free service, upload and keep our data there, and make them available to us and others.
Equipment installed, plant characteristics, and ratings
PV panels: Sharp ND167U1, installed: Two strings with 12 panels each
Inverter: SMA SB4000US (240V)
Maximum power voltage (per panel): 23.5 V
Maximum power (per panel): 167 W
Minimum power (per panel): 150.3 W
Maximum power current (per string): 7.1 A
Plant maximum power voltage (23.5 V * 12 panels): 282 V
Plant maximum power current (7.1 A * 2 strings): 14.2 A
Plant Maximum Power, STC-rating(167 W * 24 panels): 4008 W (4 kW)
Plant Maximum Power, PTC-rating*(147.1 W * 24 panels): 3530.4 W (3.53 kW)
Plant Power, PTC-rating, incl. Inverter Efficiency*(96%): 3389.184 W (3.39 kW)
Plant Power, PTC, incl. Inverter Efficiency and EPBB* Design Factor(0.094): 3334.957 W (3.33kW)
* All based on site-specific calculations performed at http://www.csi-epbb.com STC-Rating = "Factory Standard Test Conditions" = 1000 watts per square meter solar irradiance, 1.5 Air Mass and 25 degree C. cell temperature PTC-Rating = "PV USA Test Conditions" (University of Davis, California) = 1000 watts per square meter solar irradiance, 1.5 Air Mass, 20 degree C. cell temperature at 10 meters above ground level and wind speed of 1 meter per second.
PG&E rates
These are a science in itself: The rate schedules E-1, E-6, or E-7 may apply to non-solar- (E-1) or solar-based (E-7, E-6) installations. The rate schedules define which price you pay for the electricity you may still need. Make sure to do the right thing (which is?). Since installation of the TOU Meter (on July 16), we are now on an E-7 rate schedule.
Time-Of-Use (TOU) Meter
Part of a solar installation is a more sophisticated meter, to measure the electricity coming into and going out of your system, depending on the time of the day (TOU = time of use). The tariffs E-6 and E-7 are based on a time-of-use model. The day is divided into peak (generally, 12 noon to 6 p.m., higher price per kWh) and off-peak (all other times, lower price per kWh), sometimes even part-peak periods. Some pictures and explanations about the meter.
Electricity bills will look different
With the arrival of your new solar installation, we will also get an additional "bill" from PG&E each month. Well, it is not really a bill, but an additional monthly statement which will detail our net-generation and net-consumption. It will also track our total charges/credits throughout the true up period. Gas usage, fees, and all other "miscellaneous items" will continue to be listed on our regular bill. True up period? Yep, another new term: The true up is the annual reconciliation of all charges and/or credits accrued at the end of your 12-month billing cycle, usually coinciding with the anniversary date of our first connection to the external grid. Can we say the moment of truth?
A short description of the events following our decision to "go solar" up to the point where we were connected to the power grid and got the permission to feed surplus electricity into it. Almost three months from start to finish, given the overall project size, its complexity, and the number of parties involved ... not so bad, not so bad at all ;-).
April 24, 2007 (Day 1)
Site inspection through Renewable Power Solutions (a San Jose-based contractor), looking at the roof and access to it, measuring orientation of the house, calculating the required number of panels (Q: "Do you want to bring your bill down to the baseline or are you striving to ideally generate the equivalent of 100% of your consumed energy?", A: "The latter."), initial numbers of a) installable capacity (4kW, based on a consumption of 6408 kWh from 2006/05 through 2007/04, calculated: 12 mo kWh/(0.18*8760), b) approximate costs in $$, and c) some information about how much money to expect from the State of California and as a tax incentive.
Waiting to hear from another contractor to provide similar information.
April 30, 2007 (Day 7)
Power Solutions gave us some information about the parts, he was planning to propose for the installation. With that information, we went to the "California Solar Initiative - Expected Performance Based Buydown Calculator", or EPBB, for short. It is a handy tool to estimate the amount of money that you might expect California to contribute to your installation. We entered the required information (parts, number of modules, roof orientation, module tile: it all looked like this), and received an expected amount back from the calculator, adding up to this.
Of course, at the same time, you should keep track of the "California Solar Initiative / Self-Generation Incentive Program / Statewide Trigger Point Tracker": The page is updated daily and provides an interested "operator" with information, when the current level of funding through California (2.50 US $ per Watt max.) will be running out and replaced by a level with smaller incentives. The California approach consists of 10 phases, the last one supporting your installation with a mere 0.20 US $ per Watt. Better to join the club early!
May 3, 2007 (Day 10)
Discussed proposal, switched from the Fat Spaniel monitoring options to the one SMA (the inverter manufacturer) is offering. Fat Spaniel seems to have only limited options for an owner to configure and use the options of the proprietary hardware, they also start charging for the software license after five years. SMA offers more open hardware that can be configured in many ways, data collection on their servers is offered free of charge for an unlimited period of time. Their monitoring product, WebBox, is basically an integrated webserver that also provides options to send data to a monitoring facility or notification emails to everybody who needs to get them.
Decision was made, we signed the contract and the required forms. Paperwork will go out to PG&E soon.
May 10, 2007 (Day 17)
May 10 was the day that we (our contractor) got the confirmation from PG&E that they had received our reservation request for our project (A-0970, 3.335 kW [their kW number is different from our calculation, since PG&E is basing their calculations on geographical region within California, orientation, and tilt of the installation, while our kW number is based on the nominal values of the components]). There are sporadically updated PG&E resources on the we indicating that there currently might be a six week backlog in handling applications and have them appear in statistics, spreadsheets, etc. Hence, our (moderately optimistic) best guess that we might get our project approved around June 20. Waiting ...
June 21, 2007 (Day 59)
Finally: Our contractor called today that he had received the initial approval (from PG&E) of our application and was ready to start the construction. Over the last weeks, he had also received the permit from the city of San Jose for the required changes to our house. All in all: Ready to go! Announced starting day: Monday or Tuesday, June 25/26.
June 26, 2007 (Day 64)
Construction/installation started today. Discussed positioning of the inverter (avoid sun exposure to prevent "derating"!) and ways to run the wires. The crew is getting the support structure for the panels in place. And ... we have an alien in our backyard, check out the pictures below.
June 27, 2007 (Day 65)
As of the end of today, all solar panels and the inverter are installed.
June 29, 2007 (Day 67)
The work has been progressing steadily. Today, the system actually started to generate power and, yes, the meter started spinning backward. The WebBox is connected and has started to push data to SMA's "Sunny Portal", where we have started to make some OeverMeyer statistics available for the public. Some loose ends need to be picked up here and there, but basically: We are up and running. Things left to do are getting through the building permit inspection of the City of San Jose, then through a PG&E inspection. At some point, we will get a new digital meter installed, will have to switch to a new electricity rate schedule, and then get different and (hopefully) lower utility invoices. The feeling to have a base camp below Mount Sustainability: Priceless!
July 5, 2007 (Day 73)
Inspection #1: A City of San Jose inspector stopped by early to sign-off on the modifications to the house and the electrical installation of the solar "plant". It was a calm and smooth procedure, with only a few minor changes required (the inspector waited for them to be completed before he signed). The approved building permit is now the missing piece to both complete the application for the CSI incentive funds and for the modifications in the context of the "Net-Metering Agreement" with PG&E (the contract between us and PG&E that we are officially allowed to feed electricity into the grid and that our electricity import and export will be measured by a new digital meter, based on a time-of-use schedule).
July 16, 2007 (Day 84)
PG&E installed a new meter, a so-called TOU (Time-of-use) Meter. The installation was announced by a letter from the PG&E Solar Initiative project management, but no appointment was made, neither was a phone call received to talk about scheduling or other details. On the other hand, it did not seem necessary to do so, though. First thing that alerted me to the installation was a power outage that I noticed on the Sunny Portal pages. In any case, the meter is installed. Tags on the meter also indicate that E-7 will be our rate schedule (as assumed elsewhere on this page).
July 18, 2007 (Day 86)
We received the "express written permission to operate" our 4 kW photovoltaic plant from PG&E in the mail. Contrary to what we heard before from other folks, PG&E's turn-around time continues to be quite short. We can not complain here at all: Responsiveness overall was quite good.
The written permission was the last thing we needed to have our contractor claim our rebate from the California Solar Initiative. That package is now on its way and we are waiting for the check, let's see how long this one will take.
August 4, 2007 (Day 113)
August 4 marks the official end day of the 487 North 9th solar plant project: PG&E's rebate check has arrived. At the same time, our monthly electricity billing has ceased: What we will be getting from now on is a monthly "net energy metering electric statement", which is not a bill, but a summary of our monthly electricity consumption vs. production during peak and off-peak hours. After 12 months, at the end of the " true-up period", we will get an actual bill telling us the amount due (or not?) for the last 12 months. Well, still 11 months to go until then. For the time being, we are continuing to enjoy the "priceless feeling" ... (see above).
The meter is cycling through six displays, the first of which not shown here, since it is simply a display test (all LED segments turned on). Note the handwritten hint that E-7 is the rate schedule this meter has been programmed to apply. (Move your cursor over the images to zoom in on meter details.)
(Display ID 99) Current kW
Value here is -0.27, indicating the plant is producing 0.27 kW more than we are actually consuming. These 0.27 kW are currently being fed into the grid.
Corresponding (and replacing the old rotating wheel), the bottom left area of the display shows a left arrow, together with "moving blocks" next to it (compare with the following pictures) indicating that energy is being exported to PG&E.
(Display ID 01) Meter date Well, the current date seems to be 07/16/07. Which is the month which is the year? Time will tell, don't get me started.
By the way, "A" in the upper left corner indicates that we are in the peak hours of the E-7 rate schedule (12 noon to 6 pm). A "C" below the "A" would indicate off-peak hours.
(Display ID 02) Meter time 17.20
(Display ID 04) Total kWh Indicating the net total of all kWh, we have sent to or taken from the grid. When installed, the meter is set to 50000 initially, in order to provide some padding for "kWh over-producers".
(Display ID 05) TOU (Time of use) kWh - Peak Indicating the net kWh, sent to and taken from the grid during peak hours (12 noon to 6 pm). Off-peak hours are being calculated, by the way, through subtracting this number from the total kWh (display 04).
