2009 Bay Area Solar Installation Data was released in July 2009
California has offered financial incentives for grid-tied solar electric systems (PV) since 1998, and in January 2007, the state implemented a new incentive program through the California Public Utilities Commission (CPUC) called the California Solar Initiative (CSI). The CSI is a ten-year $2.2 billion incentive program with the goal of installing 1,940 megawatts of solar power on the equivalent of one million rooftops. The CSI has been a much heralded program due to its size, length, and cutting-edge policy goal of establishing a sustainable solar industry. It is administered by Pacific, Gas & Electric (PG&E) in Northern California. For more detailed information about the California Solar Initiative, please visit www.gosolarcalifornia.com.

This report by the Northern California Solar Energy Association (NorCal Solar) uses publicly available solar incentive data to describe the number and amount of grid-tied solar photovoltaic (PV) installations from the start of the CSI through 12/31/2008 in ten Bay Area counties and 163 cities and communities.[1]

According to our analysis, in 2007 and 2008, the entire state installed 17,245 PV systems producing over 178 megawatts (MW) of power at a cost of $1.64 billion.[2] The 10 counties of the Bay Area have installed 6,904 PV systems producing over 55 megawatts (MW) of power at a cost of $514 million representing 31% of the solar installed in the state during this period.

Total Solar Installed in California in 2007 & 2008





Cost ($M)

Bay Area








In 2008, 8,907 PV systems producing over 110 megawatts of power were installed statewide at a cost of $1.04 billion. 3,630 PV systems producing over 31 megawatts of power were installed in the Bay Area representing 28% of the solar installed in the state and a 26% growth over 2007.

Total Solar Installed in California in 2008




Cost ($M)

Bay Area








Data Analysis and Rationale

NorCal Solar focused on ten Bay Area counties because this region leads the growing wave of solar adoption across the state. Apparent reasons for strong solar adoption in the Bay Area include solar-friendly utility rates, net metering, ample sun exposure, supportive local governments, a strong environmental ethic, and the attention brought to PV technology through the Vote Solar initiative in 2000.

In comparing communities equitably, we defined the parameters for cities based on population using the guidelines of the League of California Cities:

  • small - 2,500 - 25,000
  • medium -25,000 - 100,000
  • large – more than 100,000

Data for cities smaller than 2,500 citizens is included in the "county" analysis only. [3]

One of the key features of the California incentive programs is that they seek to stimulate increased economies of scale and resulting reductions in the price of PV installations over time. That is why the incentives are designed to ratchet down over time on a dollar/watt basis.  With this report, we start tracking the average total installed cost so that readers may evaluate the extent to which installed costs actually drop over time. The values for 2008 are shown below:

Average Cost/Watt for 2008:

< 10 kW - $10.45
10 kW - 30 kW -  $9.91
> 30 kW - $ 8.67

The raw data for this report includes records from the California Solar Initiative (CSI), the Self-Generation Incentive Program (SGIP) [4], the Emerging Renewables Program (ERP) and from the municipal owned City of Palo Alto Utilities (CPAU). The other two municipal owned utilities in the Bay Area (Silcon Valley Power or Alameda Municipal Power) were given the opportunity, but did not provide solar installation data. The records used in the CSI data set were limited to "Completed" or "PBI - In Payment" in the Status field as of the end of 2008. PBI means Permormance Based Incentive. PBIs are paid over 5 years verses Expected Performance-Based Buydown (EPBB) incentives which are paid upon completion of the system. The "CSI Rating" was used for watt calculations.

The latest data sets were used to calculate the cumulative installed solar since January 1, 2007. For some cities and counties, this led to slightly different numbers than were published last year due to corrections made by PG&E. The difference in data is 1% - 2% and did not change any of last year's winners. Also, it is important to note that the CPUC and PG&E are countng "Payment Pending" and "Incentive Claim Form Submissions and Review" records as "completed systems". This leads to NorCal's numbers being around 30% less than what is stated by the CPUC and PG&E. We plan to review and discuss this issue for next year's report. It is also important to note that in performing this analysis, over 200 errors to the Bay Area's data set were reported and corrected by the CPUC and PG&E. Mostly typos in the city name and/or incorrect or missing counties.

On the Bay Area Solar Installation pages for 2007-2008 and for 2008 only, we have provided the raw data used for the reports, Excel Pivot Tables totaling the relevant data and sortable Lists for both cities and counties.  Readers can use these resources to sort and search for specific regional data.

The process to determine the winners was as follows:

1. Limit the CSI, SGIP & ERP (this does not include NSHP data) and CPAU data sets to the 10 Bay Area counties and merge them together.
2. Clean the data by correcting city spelling errors and incorrect or missing county entries & remove any irrelevant fields.
3. Create an Excel Pivot Table from the data set and create a sortable list.
4. Create a worksheet with population data for the per capita analysis.
5. Create worksheets for small, medium, and large cities and counties and create sort able lists for the various columns.
6. Sort the columns of interest by descending order based on the ranking data item to determine the winners.
7. Verify the data accuracy by checking our summary data against the original raw data. [5]
8. Calculate the totals for all of California to determine the percent installed in the Bay Area

NorCal Solar plans to update this data annually.


NorCal Solar’s Board of Directors is pleased to report on the commendable and steady progress in PV installations in the entire state and specifically in the Northern California region. This report and subsequent editions seek to raise awareness of the success of
various communities in implementing solar PV technology.

The annual BASI report is intended the ongoing progress of PV installations in the Bay Area. Most importantly, NorCal Solar’s Board of Directors and staff are confident that the trend of increased PV installations will continue over the years to come as this technology
represents an important cornerstone to an environmentally sound and sustainable society. NorCal Solar believes that these goals can be achieved through ongoing supportive state policies and favorable education programs that will enable consumers to increasingly
utilize solar energy in its many forms.


The Bay Area Solar Installation (BASI) report has been published annually since 2006 as part of the City Solar Awards (CSAs) which are inteded to recognize cities and counties for their leadership efforts in promoting solar adoption within their borders. The BASI report concept was an idea brought to NorCal Solar by volunteer member Bill LaCommare, president of MediaWorks Software in Pleasanton. Under the supervision of NorCal Solar, Mr. LaCommare completed the first analysis in July 2006 for completed solar installations under 15 kW in 7 Bay Area counties from 1998 - 2005. In July 2009, the 4th report was completed using rebate data from 3 data sets from the start of 2007 which is when the California Solar Initiative (CSI) began.

The 1st Annual City Solar Awards ceremony was held at the Berkeley City Club in October, 2007 and was attended by over 160 people with significant sponsor support. Public Relations was handled by ElevatorPR, and in 2007, the BASI report received front-page, headline story coverage in the SF Chronicle and many other news outlets.


NorCal Solar’s Board of Directors thanks the staff and volunteer members who have made this report possible. We have listed them below. The Board would also like to thank Molly Sterkel of the California Public Utilities Commission, Lisa Shell and Chuck Hornbrook of Pacific Gas and Electric, and Lindsay Joye from Palo Alto Utilities for data assistance.

•    Data Collection, Cleaning, Merging and Analysis: Bill LaCommare
•    Assistance and Support with Data Acquisition: CPUC, PG & E, and CPAU

•    Report, WebPages, and Educational Materials: Elisabeth Holmgren, Carla Brown, Bill LaCommare, and NorCal Solar’ Board of Directors including: Claudia Wentworth, Elaine Hebert, Patty Chin, Marvin Hamon, Darren Malvin, Bruce Lymburn, and Rachel Huang.


The views expressed in this report are based on the data set provided as of July 2, 2009 and do not necessarily reflect the views of our members, sponsors, or those who provided review. All attempts were made to present the actual incentive data within the specified parameters. Please report any missing incentive data to \n // --> This email address is being protected from spambots. You need JavaScript enabled to view it. This e-mail address is being protected from spam bots, you need JavaScript enabled to view it

[1] Data Sources: CSI, ERP, CPAU and SGIP

[2] Statewide totals only include data from the CSI, ERP and SGIP data sets and not from municipal owned utilities like CPAU and SMUD.

[3] Population data from the city's website or Census data from 2000 & 2006

[4] SGIP records are from 1/01/07 through 8/31/08. 45 records in PG&E's service territory did not include city information and were excluded from analysis. Verve Consulting tracked down city info for 14 of theses records for 2007 indicated in Red in the data set. Including the remaining 31 records would increase the total solar in Northern California by 6.9 megawatts. The Center for Sustainalble Energy, who manages the SGIP data set, was alerted to the problem, but has not provided the missing information as of this time.

[5] After correctling city spelling errors and incorrect counties, we estimatate the BASI report is within 3-5% margin of the original records.

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